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  • 1.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Howells, Tim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures2019In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 131, no 2, p. 604-611Article in journal (Refereed)
    Abstract [en]

    Objective: Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.

    Methods: Fifty-two patients with severe TBI (median age 24 years, range 9–61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.

    Results: All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%–13%, p = 0.004) and young age (−0.2% of GMT with ICP > 20 mm Hg, 95% CI −0.07% to −0.3%, p = 0.002) were associated with increased ICP.

    Conclusions: Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

    Abbreviations: ADC = apparent diffusion coefficient; CPP = cerebral perfusion pressure; DAI = diffuse axonal injury; DWI = diffusion-weighted imaging; EVD = external ventricular drain; GCS = Glasgow Coma Scale; GMT = good monitoring time; GOSE = Glasgow Outcome Scale–Extended; ICC = intraclass correlation coefficient; ICP = intracranial pressure; MAP = mean arterial blood pressure; NICU = neurointensive care unit; SN-T = substantia nigra and mesencephalic tegmentum; SWI = susceptibility-weighted imaging; TBI = traumatic brain injury; T2*GRE = T2*-weighted gradient echo.

  • 2.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Virhammar, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology.
    Cesarini, Kristina G
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Brain tissue Aβ42 levels are linked to shunt response in idiopathic normal pressure hydrocephalus2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, p. 1-9Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE The authors conducted a study to test if the cortical brain tissue levels of soluble amyloid beta (Aβ) reflect the propensity of cortical Aβ aggregate formation and may be an additional factor predicting surgical outcome following idiopathic normal pressure hydrocephalus (iNPH) treatment. METHODS Highly selective ELISAs (enzyme-linked immunosorbent assays) were used to quantify soluble Aβ40, Aβ42, and neurotoxic Aβ oligomers/protofibrils, associated with Aβ aggregation, in cortical biopsy samples obtained in patients with iNPH (n = 20), sampled during ventriculoperitoneal (VP) shunt surgery. Patients underwent pre- and postoperative (3-month) clinical assessment with a modified iNPH scale. The preoperative CSF biomarkers and the levels of soluble and insoluble Aβ species in cortical biopsy samples were analyzed for their association with a favorable outcome following the VP shunt procedure, defined as a ≥ 5-point increase in the iNPH scale. RESULTS The brain tissue levels of Aβ42 were negatively correlated with CSF Aβ42 (Spearman's r = -0.53, p < 0.05). The Aβ40, Aβ42, and Aβ oligomer/protofibril levels in cortical biopsy samples were higher in patients with insoluble cortical Aβ aggregates (p < 0.05). The preoperative CSF Aβ42 levels were similar in patients responding (n = 11) and not responding (n = 9) to VP shunt treatment at 3 months postsurgery. In contrast, the presence of cortical Aβ aggregates and high brain tissue Aβ42 levels were associated with a poor outcome following VP shunt treatment (p < 0.05). CONCLUSIONS Brain tissue measurements of soluble Aβ species are feasible. Since high Aβ42 levels in cortical biopsy samples obtained in patients with iNPH indicated a poor surgical outcome, tissue levels of Aβ species may be associated with the clinical response to shunt treatment.

  • 3.
    Andersson, Nina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Department of Biomedical Engineering and Informatics, Umeå University Hospital.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Department of Biomedical Engineering and Informatics, Umeå University Hospital.
    Dependency of cerebrospinal fluid outflow resistance on intracranial pressure2008In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 109, no 5, p. 918-922Article in journal (Refereed)
    Abstract [en]

    OBJECT: The outflow resistance (Rout) of the cerebrospinal fluid (CSF) system has generally been accepted by most investigators as independent of intracranial pressure (ICP), but there are also those claiming that it is not. The general belief is that this question has been investigated numerous times in the past, but few studies have actually been specifically aimed at looking at this relationship, and no study has been able to provide scientific evidence to elucidate fully this fundamental and important issue. The objective of this study was to investigate the relationship between ICP and CSF outflow in 30 patients investigated for idiopathic normal-pressure hydrocephalus. METHODS: Lumbar infusion tests with constant pressure levels were performed, and ICP and corresponding flow were measured on 6 pressure levels for each patient. All data were standardized for comparison. RESULTS: In the range of moderate increases from baseline pressure (approximately 5-12 mm Hg, mean baseline pressure 11.7 mm Hg), the assumption of a pressure-independent Rout was confirmed (p = 0.5). However, when the pressure increment from baseline pressure was larger (approximately 15-22 mm Hg), the relationship had a nonlinear tendency (p < 0.05). CONCLUSIONS: The results of this study support the classic textbook theory of a pressure-independent Rout in the normal ICP range, where the CSF system is commonly operating. However, the theory might have to be questioned in regions where ICP exceeds baseline pressure by too much.

  • 4.
    Andisheh, Bahram
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Brahme, Anders
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    Bitaraf, Mohammad Ali
    Mavroidis, Panayiotis
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    Lind, Bengt K
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    Clinical and radiobiological advantages of single-dose stereotactic light-ion radiation therapy for large intracranial arteriovenous malformations. Technical note2009In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 111, no 5, p. 919-926Article in journal (Refereed)
    Abstract [en]

    OBJECT:

    Radiation treatment of large arteriovenous malformations (AVMs) remains difficult and not very effective, even though seemingly promising methods such as staged volume treatments have been proposed by some radiation treatment centers. In symptomatic patients harboring large intracranial AVMs not amenable to embolization or resection, single-session high-dose stereotactic radiation therapy is a viable option, and the special characteristics of high-ionization-density light-ion beams offer several treatment advantages over photon and proton beams. These advantages include a more favorable depth-dose distribution in tissue, an almost negligible lateral scatter of the beam, a sharper penumbra, a steep dose falloff beyond the Bragg peak, and a higher probability of vascular response due to high ionization density and associated induction of endothelial cell proliferation and/or apoptosis. Carbon ions were recently shown to be an effective treatment for skull-base tumors. Bearing that in mind, the authors postulate that the unique physical and biological characteristics of light-ion beams should convey considerable clinical advantages in the treatment of large AVMs. In the present meta-analysis the authors present a comparison between light-ion beam therapy and more conventional modalities of radiation treatment with respect to these lesions.

    METHODS:

    Dose-volume histograms and data on peripheral radiation doses for treatment of large AVMs were collected from various radiation treatment centers. Dose-response parameters were then derived by applying a maximum likelihood fitting of a binomial model to these data. The present binomial model was needed because the effective number of crucial blood vessels in AVMs (the number of vessels that must be obliterated to effect a cure, such as large fistulous nidus vessels) is low, making the Poisson model less suitable. In this study the authors also focused on radiobiological differences between various radiation treatments.

    RESULTS:

    Light-ion Bragg-peak dose delivery has the precision required for treating very large AVMs as well as for delivering extremely sharp, focused beams to irregular lesions. Stereotactic light-ion radiosurgery resulted in better angiographically defined obliteration rates, less white-matter necrosis, lower complication rates, and more favorable clinical outcomes. In addition, in patients treated by He ion beams, a sharper dose-response gradient was observed, probably due to a more homogeneous radiosensitivity of the AVM nidus to light-ion beam radiation than that seen when low-ionization-density radiation modalities, such as photons and protons, are used.

    CONCLUSIONS:

    Bragg-peak radiosurgery can be recommended for most large and irregular AVMs and for the treatment of lesions located in front of or adjacent to sensitive and functionally important brain structures. The unique physical and biological characteristics of light-ion beams are of considerable advantage for the treatment of AVMs: the densely ionizing beams of light ions create a better dose and biological effect distribution than conventional radiation modalities such as photons and protons. Using light ions, greater flexibility can be achieved while avoiding healthy critical structures such as diencephalic and brainstem nuclei and tracts. Treatment with the light ion He or Li is more suitable for AVMs <or= 10 cm(3), whereas treatment with the light ion Li, Be, or C may be more appropriate for larger AVMs. A binomial model based on the effective number of crucial vessels in the AVM may be used quite well to predict AVM obliteration probabilities for both small and large AVMs when therapies involving either photons or light ions are used.

  • 5.
    Arnell, Kai
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Wester, Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Sjölin, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Infectious Diseases.
    Treatment of cerebrospinal fluid shunt infections in children using systemic and intraventricular antibiotic therapy in combination with externalization of the ventricular catheter: efficacy in 34 consecutively treated infections2007In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 107, no 3, p. 213-219Article in journal (Refereed)
    Abstract [en]

    OBJECT: There are no randomized studies comparing the efficacy of different antibiotic regimens for the treatment of cerebrospinal fluid (CSF) shunt infections, and in the studies that have been reported, efficacy data are limited. The aim of this study was therefore to report the authors' experience using a specific protocol for the management of shunt infections in children. Standard treatment included a two-stage procedure involving externalization of the ventricular catheter in combination with intraventricular and systemic administration of antibiotic medication followed by shunt replacement. Intraventricular treatment consisted of daily instillations of vancomycin or gentamicin with trough concentrations held at high levels of 7 to 17 mg/L for both antibiotic agents. METHODS: During a 13-year study period, the authors treated 34 consecutive intraventricular shunt infections in 30 children. Infections with coagulase-negative staphylococci predominated, and Gram-negative bacterial infection occurred in five children. Ten of the children were initially treated with intravenous antibiotic therapy for at least 3 days, but this treatment did not sterilize the CSF. After externalization of the ventricular catheter, high-dose intraventricular treatment was given for a median of 8 days (range 3-17 days) before shunt replacement. RESULTS: The CSF was found to be sterile (cultures were negative for bacteria) in one of three, seven of eight, 20 of 20, and six of six cases after 1, 2, 3, and more than 3 days' treatment, respectively. In no case was any subsequent culture positive after a negative result had been obtained. Clinical symptoms resolved in parallel with the sterilization of the CSF. There were no relapses or deaths during the 6-month follow-up period, and there have been none as of April 2007. CONCLUSIONS: Despite the ventricular catheter being left in place and the short duration of therapy, the treatment regimen described by the authors resulted in quick sterilization of the CSF, a low relapse rate, and survival of all patients in this series.

  • 6.
    Asplund, Pär
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Linderoth, Bengt
    Bergenheim, A Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    The predictive power of balloon shape and change of sensory functions on outcome of percutaneous balloon compression for trigeminal neuralgia2010In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 113, no 3, p. 498-507Article in journal (Refereed)
    Abstract [en]

    The authors have demonstrated that using a pear-shaped balloon when performing percutaneous balloon compression for trigeminal neuralgia results in longer pain relief than non-pear-shaped balloons. Other surgical parameters seemed less important with respect to pain relief. Balloon compression also, in many cases, results in hypesthesia.

  • 7.
    Backlund, EO
    Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery. Linköping University, Faculty of Health Sciences.
    Letter: Gamma hypophysectomy2004In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 100, no 6, p. 1133-1134Article in journal (Other academic)
    Abstract [en]

    n/a

  • 8.
    Behrens, Anders
    et al.
    Blekinge Hosp, Sweden; Umea Univ, Sweden.
    Elgh, Eva
    Umea Univ, Sweden.
    Leijon, Göran
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Neurology in Linköping.
    Kristensen, Bo
    Aalborg Univ Hosp, Denmark.
    Eklund, Anders
    Umea Univ, Sweden.
    Malm, Jan
    Umea Univ, Sweden.
    The Computerized General Neuropsychological INPH Test revealed improvement in idiopathic normal pressure hydrocephalus after shunt surgery2020In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 132, no 3, p. 733-740Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE The Computerized General Neuropsychological INPH Test (CoGNIT) provides the clinician and the researcher with standardized and accessible cognitive assessments in patients with idiopathic normal pressure hydrocephalus (INPH). CoGNIT includes tests of memory, executive functions, attention, manual dexterity, and psychomotor speed. Investigations of the validity and reliability of CoGNIT have been published previously. The aim of this study was to evaluate CoGNITs sensitivity to cognitive change after shunt surgery in patients with INPH. METHODS Forty-one patients with INPH (median Mini-Mental State Examination score 26) were given CoGNIT preoperatively and at a postoperative follow-up 4 months after shunt surgery. Scores were compared to those of 44 healthy elderly control volunteers. CoGNIT was administered by either a nurse or an occupational therapist. RESULTS Improvement after shunt surgery was seen in all cognitive domains: memory (10-word list test, p amp;lt; 0.01); executive functions (Stroop incongruent color and word test, p amp;lt; 0.01); attention (2-choice reaction test, p amp;lt; 0.01); psychomotor speed (Stroop congruent color and word test, p amp;lt; 0.01); and manual dexterity (4-finger tapping, p amp;lt; 0.01). No improvement was seen in the Mini-Mental State Examination score. Preoperative INPH test scores were significantly impaired compared to healthy control subjects (p amp;lt; 0.001 for all tests). CONCLUSIONS In this study the feasibility for CoGNIT to detect a preoperative impairment and postoperative improvement in INPH was demonstrated. CoGNIT has the potential to become a valuable tool in clinical and research work.

  • 9. Bjellvi, Johan
    et al.
    Flink, Roland
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Clinical Neurophysiology.
    Rydenhag, Berth
    Malmgren, Kristina
    Complications of epilepsy surgery in Sweden 1996-2010: a prospective, population-based study2015In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 122, no 3, p. 519-525Article in journal (Refereed)
    Abstract [en]

    OBJECT Detailed risk information is essential for presurgical patient counseling and surgical quality assessments in epilepsy surgery. This study was conducted to investigate major and minor complications related to epilepsy surgery in a large, prospective series. METHODS The Swedish National Epilepsy Surgery Register provides extensive population-based data on all patients who were surgically treated in Sweden since 1990. The authors have analyzed complication data for therapeutic epilepsy surgery procedures performed between 1996 and 2010. Complications are classified as major (affecting daily life. and lasting longer than 3 months) or minor (resolving within 3 months). RESULTS A total of 865 therapeutic epilepsy surgery procedures were performed between 1996 and 2010, of which 158 were reoperations. There were no postoperative deaths. Major complications occurred in 26 procedures (3%), and minor complications in 65 (7.5%). In temporal lobe resections (n = 523), there were 15 major (2.9%) and 41 minor complications (7.8%); in extratemporal resections (n = 275) there were 9 major (3.3%) and 22 minor complications (8%); and in nonresective procedures (n = 67) there were 2 major (3%) and 2 minor complications (3%). The risk for any complication increased significantly with age (OR 1.26 per 10-year interval, 95% Cl 1.09-1.45). Compared with previously published results from the same register, there is a trend toward lower complication rates, especially in patients older than 50 years. CONCLUSIONS This is the largest reported prospective series of complication data in epilepsy surgery. The complication rates comply well with published results from larger single centers, confirming that epilepsy surgery performed in the 6 Swedish centers is safe. Patient age should be taken into account when counseling patients before surgery.

  • 10.
    Blomstedt, Patric
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Transnasal surgery2012In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 117, no 2, p. 381-382Article in journal (Refereed)
  • 11. Eklund, A
    et al.
    Ågren Wilsson, A
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Andersson, N
    Bergenheim, AT
    Koskinen, LO
    Malm, J
    Two computerized methods used to analyze intracranial pressure B waves: comparison with traditional visual interpretation2001In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 94, no 3, p. 392-396Article in journal (Refereed)
    Abstract [en]

    OBJECT: Slow and rhythmic oscillations in intracranial pressure (ICP), also known as B waves, have been claimed to be one of the best preoperative predictive factors in idiopathic adult hydrocephalus syndrome (IAHS). Definitions of B waves vary widely, and previously reported results must be treated with caution. The aims of the present study were to develop a definition of B waves, to develop a method to estimate the B-wave content in an ICP recording by using computer algorithms, and to validate these procedures by comparison with the traditional visual interpretation. METHODS: In eight patients with IAHS, ICP was continuously monitored for approximately 20 hours. The ICP B-wave activity as a percentage of total monitoring time (B%) was estimated by using visual estimation according to the definition given by Lundberg, and also by using two computer algorithms (Methods I and II). In Method I each individual wave was classified as a B wave or not, whereas Method II was used to estimate the B-wave content by evaluating the B-wave power in 10-minute blocks of ICP recordings. CONCLUSIONS: The two computerized algorithms produced similar results. However, with the amplitude set to 1 mm Hg, Method I yielded the highest correlation with the visual analysis (r = 0.74). At least 5 hours of monitoring time was needed for an acceptable approximation of the B% in an overnight ICP recording. The advantages of using modern technology in the analysis of B-wave content of ICP are obvious and these methods should be used in future studies.

  • 12. Engstrand, Thomas
    et al.
    Kihlstrom, Lars
    Neovius, Erik
    Skogh, Ann-Charlott Docherty
    Lundgren, T. Kalle
    Jacobsson, Hans
    Bohlin, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Åberg, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Development of a bioactive implant for repair and potential healing of cranial defects2014In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 120, no 1, p. 273-277Article in journal (Refereed)
    Abstract [en]

    The repair of complex craniofacial bone defects is challenging and a successful result is dependent on the size of the defect, quality of the soft tissue covering the defect, and choice of reconstruction method. The objective of this study was to develop a bioactive cranial implant that could provide a permanent reconstructive solution to the patient by stimulating bone healing of the defect. In this paper the authors report on the feasibility and clinical results of using such a newly developed device for the repair of a large traumatic and therapy-resistant cranial bone defect. The patient had undergone numerous attempts at repair, in which established methods had been tried without success. A mosaic-designed device was manufactured and implanted, comprising interconnected ceramic tiles with a defined calcium phosphate composition. The clinical outcome 30 months after surgery revealed a restored cranial vault without postoperative complications. Computed tomography demonstrated signs of bone ingrowth. Examination with combined 18F-fluoride PET and CT provided further evidence of bone healing of the cranial defect.

  • 13.
    Fahlström, Andreas
    et al.
    Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala University Hospital, Uppsala, Sweden.
    Redebrandt, Henrietta Nittby
    Department of Clinical Sciences Lund, Neurosurgery, Lund University, Skane University Hospital, Lund, Sweden.
    Zeberg, Hugo
    Department of Neuroscience, Karolinska Institutet, Sweden.
    Bartek, Jiri
    Karolinska University Hospital, Stockholm, Sweden; Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
    Bartley, Andreas
    Sahlgrenska University Hospital, Gothenburg, Sweden.
    Tobieson, Lovisa
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery.
    Erkki, Maria
    Umeå University Hospital, Umeå, Sweden.
    Hessington, Amel
    Uppsala University Hospital, Uppsala, Sweden.
    Troberg, Ebba
    Skane University Hospital, Lund, Sweden.
    Mirza, Sadia
    Karolinska University Hospital, Stockholm, Sweden.
    Tsitsopoulos, Parmenion P.
    Uppsala University Hospital, Uppsala, Sweden.
    Marklund, Niklas
    Uppsala University Hospital, Uppsala, Sweden; Skane University Hospital, Lund, Sweden.
    A grading scale for surgically treated patients with spontaneous supratentorial intracerebral hemorrhage: the Surgical Swedish ICH Score2019In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Journal of Neurosurgery JNSArticle in journal (Refereed)
    Abstract [en]

    OBJECTIVE

    The authors aimed to develop the first clinical grading scale for patients with surgically treated spontaneous supratentorial intracerebral hemorrhage (ICH).

    METHODS

    A nationwide multicenter study including 401 ICH patients surgically treated by craniotomy and evacuation of a spontaneous supratentorial ICH was conducted between January 1, 2011, and December 31, 2015. All neurosurgical centers in Sweden were included. All medical records and neuroimaging studies were retrospectively reviewed. Independent predictors of 30-day mortality were identified by logistic regression. A risk stratification scale (the Surgical Swedish ICH [SwICH] Score) was developed using weighting of independent predictors based on strength of association.

    RESULTS

    Factors independently associated with 30-day mortality were Glasgow Coma Scale (GCS) score (p = 0.00015), ICH volume ≥ 50 mL (p = 0.031), patient age ≥ 75 years (p = 0.0056), prior myocardial infarction (MI) (p = 0.00081), and type 2 diabetes (p = 0.0093). The Surgical SwICH Score was the sum of individual points assigned as follows: GCS score 15–13 (0 points), 12–5 (1 point), 4–3 (2 points); age ≥ 75 years (1 point); ICH volume ≥ 50 mL (1 point); type 2 diabetes (1 point); prior MI (1 point). Each increase in the Surgical SwICH Score was associated with a progressively increased 30-day mortality (p = 0.0002). No patient with a Surgical SwICH Score of 0 died, whereas the 30-day mortality rates for patients with Surgical SwICH Scores of 1, 2, 3, and 4 were 5%, 12%, 31%, and 58%, respectively.

    CONCLUSIONS

    The Surgical SwICH Score is a predictor of 30-day mortality in patients treated surgically for spontaneous supratentorial ICH. External validation is needed to assess the predictive value as well as the generalizability of the Surgical SwICH Score.

  • 14.
    Fornander, Lotta
    et al.
    Karolinska Institute.
    Nyman, Torbjörn
    Östergötlands Läns Landsting, Anaesthesiology and Surgical Centre, Department of Anaesthesiology and Intensive Care VHN.
    Hansson, Thomas
    Linköping University, Department of Biomedicine and Surgery, Division of surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Ragnehed, Mattias
    Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Faculty of Health Sciences.
    Brismar, Tom
    Karolinska Institute.
    Age- and time-dependent effects on functional outcome and cortical activation pattern in patients with median nerve injury: a functional magnetic resonance imaging study Clinical article2010In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 113, no 1, p. 122-128Article in journal (Refereed)
    Abstract [en]

    Object. The authors conducted a study to determine age- and time-dependent effects on the functional outcome after median nerve injury and repair and how such effects are related to changes in the pattern of cortical activation in response to tactile stimulation of the injured hand. Methods. The authors studied 11 patients with complete unilateral median nerve injury at the wrist repaired with epineural suture. In addition, 8 patients who were reported on in a previous study were included in the statistical analysis. In the entire study cohort, the mean age at injury was 23.3 +/- 13.4 years (range 7-57 years) and the time after injury ranged from 1 to 11 years. Sensory perception was measured with the static 2-point discrimination test and monofilaments. Functional MR imaging was conducted during tactile stimulation (brush strokes) of Digits II-III and IV-V of both hands, respectively. Results. Tactile sensation was diminished in the median territory in all patients. The strongest predictor of 2-point discrimination was age at injury (p less than 0.0048), and when this was accounted for in the regression analysis, the other age- and time-dependent predictors had no effect. The activation ratios (injured/healthy hand) for Digit II-III and Digit IV-V stimulation were positively correlated (rho 0.59, p less than 0.011). The activation ratio for Digit II-III stimulation correlated weakly with time after injury (p less than 0.041). The activation ratio of Digits IV-V correlated weakly with both age at injury (p less than 0.048) and time after injury (p less than 0.033), but no predictor reached significance in the regression model. The mean ratio of ipsi- and contralateral hemisphere activation after stimulation of the injured hand was 0.55, which was not significantly different from the corresponding ratio of the healthy hand (0.66). Conclusions. Following a median nerve injury (1-11 years after injury) there may be an initial increase in the volume of the cortical representation, which subsequently declines during the restoration phase. These dynamic changes may involve both median and ulnar nerve cortical representation, because both showed negative correlation with time after injury. These findings are in agreement with animal studies showing that cortical plasticity is an important mechanism for functional recovery after peripheral nerve injury and repair.

  • 15.
    Fridriksson, Steen
    et al.
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Säveland, Hans
    Jakobsson, Karl-Erik
    Edner, Göran
    Zygmunt, Stefan
    Brandt, Lennart
    Hillman, Jan
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Intraoperative complications in aneurysm surgery: a prospective national study2002In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 96, no 3, p. 515-522Article in journal (Refereed)
    Abstract [en]

    Object. With increasing use of endovascular procedures, the number of aneurysms treated surgically will decline. In this study the authors review complications related to the surgical treatment of aneurysms and address the issue of maintaining quality standards on a national level.

    Methods. A prospective, nonselected amalgamation of every aneurysm case treated in five of six neurosurgical centers in Sweden during 1 calendar year was undertaken (422 patients; 7.4 persons/100,000 population/year). The treatment protocols at these institutions were very similar. Outcome was assessed using clinical end points. In this series, 84.1% of the patients underwent surgery, and intraoperative complications occurred in 30% of these procedures. Poor outcome from technical complications was seen in 7.9% of the surgically treated patients. Intraoperative aneurysm rupture accounted for 60% and branch sacrifice for 12% of all technical difficulties. Although these complications were significantly related to aneurysm base geometry and the competence of the surgeon, problems still occurred apparently at random and also in the best of hands (17%). The temporary mean occlusion time in the patients who suffered intraoperative aneurysm rupture was twice as long as the temporary arrest of blood flow performed to aid dissection.

    Conclusions. The results obtained in this series closely reflect the overall management results of this disease and support the conclusion that surgical complications causing a poor outcome can be estimated on a large population-based scale. Intraoperative aneurysm rupture was the most common and most devastating technical complication that occurred. Support was found for a more liberal use of temporary clips early during dissection, regardless of the experience of the surgeon. Temporary regional interruption of arterial blood flow should be a routine method for aneurysm surgery on an everyday basis. A random occurrence of difficult intraoperative problems was clearly shown, and this factor of unpredictability, which is present in any preoperative assessment of risk, strengthens the case for recommending neuroprotection as a routine adjunct to virtually every aneurysm operation, regardless of the surgeon's experience.

  • 16.
    Gasslander, Johan
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience. Departments of Cardiology and Health, Medicine and Caring Services, Linkoping University, Vrinnevi General Hospital Norrköping.
    Sundström, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Koskinen, Lars-Owe D.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Risk factors for developing subdural hematoma: a registry-based study in 1457 patients with shunted idiopathic normal pressure hydrocephalus2020In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, p. 1-10Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Subdural hematomas and hygromas (SDHs) are common complications in idiopathic normal pressure hydrocephalus (iNPH) patients with shunts. In this registry-based study, patients with shunted iNPH were screened nationwide to identify perioperative variables that may increase the risk of SDH.

    METHODS: The Swedish Hydrocephalus Quality Registry was reviewed for iNPH patients who had undergone shunt surgery in Sweden in 2004-2014. Potential risk factors for SDH were recorded preoperatively and 3 months after surgery. Drug prescriptions were identified from a national pharmacy database. Patients who developed SDHs were compared with those without SDHs.

    RESULTS: The study population consisted of 1457 patients, 152 (10.4%) of whom developed an SDH. Men developed an SDH more often than women (OR 2.084, 95% CI 1.421-3.058, p < 0.001). Patients on platelet aggregation inhibitors developed an SDH more often than those who were not (OR 1.733, 95% CI 1.236-2.431, p = 0.001). At surgery, shunt opening pressures had been set 5.9 mm H2O lower in the SDH group than in the no-SDH group (109.6 ± 24.1 vs 115.5 ± 25.4 mm H2O, respectively, p = 0.009). Antisiphoning devices (ASDs) were used in 892 patients but did not prevent SDH. Mean opening pressures at surgery and the follow-up were lower with shunts with an ASD, without causing more SDHs. No other differences were seen between the groups.

    CONCLUSIONS: iNPH patients in this study were diagnosed and operated on in routine practice; thus, the results represent everyday care. Male sex, antiplatelet medication, and a lower opening pressure at surgery were risk factors for SDH. Physical status and comorbidity were not. ASD did not prevent SDH, but a shunt with an ASD allowed a lower opening pressure without causing more SDHs.

  • 17.
    Gunnarsson, Thorsteinn
    et al.
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Theodorsson, Annette
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Karlsson, Per
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Fridriksson, Steen
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Boström, Sverre
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Persliden, Jan
    Linköping University, Department of Medicine and Care, Radio Physics. Linköping University, Faculty of Health Sciences.
    Johansson, Ingegerd
    Hillman, Jan
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Mobile computerized tomography scanning in the neurosurgery intensive care unit: increase in patient safety and reduction of staff workload2000In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 93, no 3, p. 432-436Article in journal (Refereed)
    Abstract [en]

    Object. Transportation of unstable neurosurgical patients involves risks that may lead to further deterioration and secondary brain injury from perturbations in physiological parameters. Mobile computerized tomography (CT) head scanning in the neurosurgery intensive care (NICU) is a new technique that minimizes the need to transport unstable patients. The authors have been using this device since June 1997 and have developed their own method of scanning such patients.

    Methods. The scanning procedure and radiation safety measures are described. The complications that occurred in 89 patients during transportation and conventional head CT scanning at the Department of Radiology were studied prospectively. These complications were compared with the ones that occurred during mobile CT scanning in 50 patients in the NICU. The duration of the procedures was recorded, and an estimation of the staff workload was made. Two patient groups, defined as high- and medium-risk cases, were studied. Medical and/or technical complications occurred during conventional CT scanning in 25% and 20% of the patients in the high- and medium-risk groups, respectively. During mobile CT scanning complications occurred in 4.3% of the high-risk group and 0% of the medium-risk group. Mobile CT scanning also took significantly less time, and the estimated personnel cost was reduced.

    Conclusions. Mobile CT scanning in the NICU is safe. It minimizes the risk of physiological deterioration and technical mishaps linked to intrahospital transport, which may aggravate secondary brain injury. The time that patients have to remain outside the controlled environment of the NICU is minimized, and the staff's workload is decreased.

  • 18.
    Gunnarsson, Tove
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Psychiatry . Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Psychiatry.
    Leszniewski, W
    Linkoping Univ Hosp, Dept Neurosurg, S-58185 Linkoping, Sweden Linkoping Univ Hosp, Dept Radiol, S-58185 Linkoping, Sweden Linkoping Univ Hosp, Dept Pathol, S-58185 Linkoping, Sweden.
    Bak, J
    Davidsson, L
    Linkoping Univ Hosp, Dept Neurosurg, S-58185 Linkoping, Sweden Linkoping Univ Hosp, Dept Radiol, S-58185 Linkoping, Sweden Linkoping Univ Hosp, Dept Pathol, S-58185 Linkoping, Sweden.
    An intradural cervical chordoma mimicking a neurinoma - Case illustration2001In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 95, no 1, p. 144-144Other (Other academic)
  • 19.
    Gunnarsson, Tove
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery UHL.
    Leszniewski, W
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery UHL.
    Bak, Julia
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Molecular and Immunological Pathology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Davidsson, L
    An intradural cervical chordoma mimicking a neurinoma. Case illustration.2001In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 95, p. 144-144Article in journal (Refereed)
  • 20.
    Hansson, Thomas
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Brismar, T
    Loss of sensory discrimination after median nerve injury and activation in the primary somatosensory cortex on functional magnetic resonance imaging2003In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 99, no 1, p. 100-105Article in journal (Refereed)
    Abstract [en]

    Object. The aim of this study was to assess the effects of median nerve injury and regeneration on neuronal activation in the somatosensory cortex by means of functional magnetic resonance (fMR) imaging and somatosensory evoked potentials (SSEPs). Methods. Ten injured male patients (mean age 26 years) were examined 15 to 58 months after a total transection of the median nerve at the wrist that was repaired with epineural sutures. Two-point discrimination was lost in Digit II-III and sensory nerve conduction displayed decreased velocity (-29%) and amplitude (-84%) in the median nerve at the wrist. The fMR images were obtained during tactile stimulation (gentle strokes) performed separately on the volar surface of either Digit II-III or Digit IV-V (eight patients: two were excluded because of movement artifacts). The SSEPs were obtained using electrical stimulation proximal to the median nerve lesion. Conclusions. Patients with loss of sensory discrimination after median nerve damage and regeneration had larger areas of activation in fMR imaging near the contralateral central sulcus during tactile stimulation of the injured compared with the noninjured hand. The increase relative to the unaffected hand was 43% (p < 0.02) for Digit II-III stimulation and 46% (p < 0.02) for Digit IV-V stimulation. The SSEP data showed normal latency and amplitude. The enlarged area of cortical activation may be the result of reorganization, and it may indicate that larger cortical areas are involved in the discriminatory task after a derangement of the peripheral input.

  • 21.
    Hillman, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery UHL.
    Population-based analysis of arteriovenous malformation treatment2001In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 95, no 4, p. 633-637Article in journal (Refereed)
    Abstract [en]

    Object. The author sought to describe overall management data on cerebral arteriovenous malformations (AVMs) and to focus the actuarial need for different treatment modalities on a population-based scale. Such data would seem important in the planning of regional or national multimodality strategies for the treatment of AVMs. This analysis of a nonselected, consecutive series of patients representing every diagnosed case of cerebral AVM in a population of 1,000,000 over one decade may serve to shed some light on these treatment aspects. Methods. During the 11-year period from 1989 to 1999, data from every patient harboring a cerebral AVM that was presented clinically or discovered incidentally in a strictly defined population of 986,000 people were collected prospectively. No patient was lost to follow up. There were 12.4 de novo diagnosed AVMs per 1,000,000 population per year (135 AVMs). Large high-grade AVMs (Spetzler-Martin classification) were rare, and Grade 1 to 3 lesions represented 85% of the caseload. Hemorrhage was the initial manifestation of AVM in 69.6% of the cases. Intracerebral hematoma was the most common hemorrhagic manifestation occurring in 78 patients. There were 4.4 cases per 1,000,000 population per year of hematomas needing expedient surgical evacuation. In the remaining patients who did not require hematoma surgery, small, critically located Grade 3 and Grade 4 lesions amounted to 1.6 cases per 1,000,000 population per year. There were 5.8 cases per 1,000,000 population per year of Grade 1 to 2 and larger noncritically located Grade 3 malformations. There were 0.5 cases per 1,000,000 population per year of Grade 5 AVMs. The overall outcome in 135 patients was classified as good according to the Glasgow Outcome Scale (Score 5) in 61% of the cases, and the overall mortality rate was 9%. Conclusions. In centers with population-based referral, AVM of the brain is predominantly a disease related to intracranial bleeding, and parenchymal clots have a profound impact on overall management outcome. The rupture of an AVM is as devastating as that of an aneurysm. Aneurysm ruptures are more lethal, whereas AVM rupture tends to result in more neurological disability due to the high occurrence of lobar intracerebral hematoma. In an attempt to quantify the need for different modalities of AVM treatment based on a population of 1,000,000 people, figures for surgeries performed range from six to 10 operations per year and embolization as well as gamma knife surgery procedures range from two to seven per year, depending on the strategy at hand. When using nonsurgical approaches to Grade 1 to 3 lesions, the number of patients requiring treatment with more than one method for obliteration increases drastically as does the potential risk for procedure-related complications.

  • 22.
    Hillman, Jan
    et al.
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Fridriksson, Steen
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Nilsson, Ola
    Neurosurgical Department, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Yu, Zhengquan
    Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Linköping University, Faculty of Health Sciences.
    Säveland, Hans
    Neurosurgical Department, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Jakobsson, Karl-Erik
    Neurosurgical Department, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Immediate administration of tranexamic acid and reduced incidence of early rebleeding after aneurysmal subarachnoid hemorrhage: a prospective randomized study2002In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 97, no 4, p. 771-778Article in journal (Refereed)
    Abstract [en]

    Object. By pursuing a policy of very early aneurysm treatment in neurosurgical centers, in-hospital rebleeds can be virtually eliminated. Nonetheless, as many as 15% of patients with aneurysm rupture suffer ultraearly rebleeding with high mortality rates, and these individuals are beyond the reach of even the most ambitious protocol for diagnosis and referral. Only drugs given immediately after the diagnosis of subarachnoid hemorrhage (SAH) has been established at the local hospital level can, in theory, contribute to the minimization of such ultraearly rebleeding. The object of this randomized, prospective, multicenter study was to assess the efficacy of short-term antifibrinolytic treatment with tranexamic acid in preventing rebleeding.

    Methods. Only patients suffering SAH verified on computerized tomography (CT) scans within 48 hours prior to the first hospital admission were included. A 1-g dose of tranexamic acid was given intravenously as soon as diagnosis of SAH had been verified in the local hospitals (before the patients were transported), followed by doses of 1 g every 6 hours until the aneurysm was occluded; this treatment did not exceed 72 hours. In this study, 254 patients received tranexamic acid and 251 patients were randomized as controls. Age, sex, Hunt and Hess and Fisher grade distributions, as well as aneurysm locations, were congruent between the groups. Outcome was assessed at 6 months post-SAH by using the Glasgow Outcome Scale (GOS). Vasospasm and delayed ischemic neurological deficits were classified according to clinical findings as well as by transcranial Doppler (TCD) studies. All events classified as rebleeding were verified on CT scans or during surgery.

    Conclusions. More than 90% of patients reached the neurosurgical center within 12 hours of their first hospital admission after SAH; 70% of all aneurysms were clipped or coils were inserted within 24 hours of the first hospital admission. Given the protocol, only one rebleed occurred later than 24 hours after the first hospital admission. Despite this strong emphasis on early intervention, however, a cluster of 27 very early rebleeds still occurred in the control group within hours of randomization into the study, and 13 of these patients died. In the tranexamic acid group, six patients rebled and two died. A reduction in the rebleeding rate from 10.8 to 2.4% and an 80% reduction in the mortality rate from early rebleeding with tranexamic acid treatment can therefore be inferred. Favorable outcome according to the GOS increased from 70.5 to 74.8%. According to TCD measurements and clinical findings, there were no indications of increased risk of either ischemic clinical manifestations or vasospasm that could be linked to tranexamic acid treatment. Neurosurgical guidelines for aneurysm rupture should extend also into the preneurosurgical phase to guarantee protection from ultraearly rebleeds. Currently available antifibrinolytic drugs can provide such protection, and at low cost. The number of potentially saved lives exceeds those lost to vasospasm.

  • 23.
    Hillman, Jan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery UHL.
    Åneman, Oscar
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion.
    Persson, Mikael
    Anderson, Chris
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Division of dermatology and venereology. Östergötlands Läns Landsting, Centre for Medicine, Department of Dermatology and Venerology in Östergötland.
    Dabrosin, Charlotta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Oncology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Mellergård, Pekka
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Neurosurgery. Östergötlands Läns Landsting, Reconstruction Centre, Department of Neurosurgery UHL.
    Variations in the response of interleukins in neurosurgical intensive care patients monitored using intracerebral microdialysis2007In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 106, no 5, p. 820-825Article in journal (Refereed)
    Abstract [en]

    Object. The aim of this study was to make a preliminary evaluation of whether microdialysis monitoring of cytokines and other proteins in severely diseased neurosurgical patients has the potential of adding significant information to optimize care, thus broadening the understanding of the function of these molecules in brain injury. Methods. Paired intracerebral microdialysis catheters with high-cutoff membranes were inserted in 14 comatose patients who had been treated in a neurosurgical intensive care unit following subarachnoidal hemorrhage or traumatic brain injury. Samples were collected every 6 hours (for up to 7 days) and were analyzed at bedside for routine metabolites and later in the laboratory for interleukin (IL)-1 and IL-6, in two patients, vascular endothelial growth factor and cathepsin-D were also checked. Aggregated microprobe data gave rough estimations of profound focal cytokine responses related to morphological tissue injury and to anaerobic metabolism that were not evident from the concomitantly collected cerebrospinal fluid data. Data regarding tissue with no macroscopic evidence of injury demonstrated that IL release not only is elicited in severely compromised tissue but also may be a general phenomenon in brains subjected to stress. Macroscopic tissue injury was strongly linked to IL-6 but not IL-1b activation. Furthermore, IL release seems to be stimulated by local ischemia. The basal tissue concentration level of IL-1b was estimated in the range of 10 to 150 pg/ml, for IL-6, the corresponding figure was 1000 to 20,000 pg/ml. Conclusions. Data in the present study indicate that catheters with high-cutoff membranes have the potential of expanding microdialysis to the study of protein chemistry as a routine bedside method in neurointensive care.

  • 24.
    Howells, Tim
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Elf, Kristin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Jones, Patricia
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Piper, Ian
    Nilsson, Pelle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Andrews, Peter
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma2005In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 102, no 2, p. 311-317Article in journal (Refereed)
    Abstract [en]

    OBJECT: The aim of this study was to compare the effects of two different treatment protocols on physiological characteristics and outcome in patients with brain trauma. One protocol was primarily oriented toward reducing intracranial pressure (ICP), and the other primarily on maintaining cerebral perfusion pressure (CPP).

    METHODS: A series of 67 patients in Uppsala were treated according to a protocol aimed at keeping ICP less than 20 mm Hg and, as a secondary target, CPP at approximately 60 mm Hg. Another series of 64 patients in Edinburgh were treated according to a protocol aimed primarily at maintaining CPP greater than 70 mm Hg and, secondarily, ICP less than 25 mm Hg for the first 24 hours and 30 mm Hg subsequently. The ICP and CPP insults were assessed as the percentage of monitoring time that ICP was greater than or equal to 20 mm Hg and CPP less than 60 mm Hg, respectively. Pressure reactivity in each patient was assessed based on the slope of the regression line relating mean arterial blood pressure (MABP) to ICP. Outcome was analyzed at 6 months according to the Glasgow Outcome Scale (GOS). The prognostic value of secondary insults and pressure reactivity was determined using linear methods and a neural network. In patients treated according to the CPP-oriented protocol, even short durations of CPP insults were strong predictors of death. In patients treated according to the ICP-oriented protocol, even long durations of CPP insult-mostly in the range of 50 to 60 mm Hg--were significant predictors of favorable outcome (GOS Score 4 or 5). Among those who had undergone ICP-oriented treatment, pressure-passive patients (MABP/ICP slope > or = 0.13) had a better outcome. Among those who had undergone CPP-oriented treatment, the more pressure-active (MABP/ICP slope < 0.13) patients had a better outcome.

    CONCLUSION: Based on data from this study, the authors concluded that ICP-oriented therapy should be used in patients whose slope of the MABP/ICP regression line is at least 0.13, that is, in pressure-passive patients. If the slope is less than 0.13, then hypertensive CPP therapy is likely to produce a better outcome.

  • 25.
    Höybye, Charlotte
    et al.
    Departments of Endocrinology and Diabetology, Otorhinolaryngology and Head and Neck Surgery, and Neurosurgery, Karolinska Hospital, Stockholm.
    Grenbäck, Eva
    Departments of Endocrinology and Diabetology, Otorhinolaryngology and Head and Neck Surgery, and Neurosurgery, Karolinska Hospital, Stockholm.
    Thorén, Marja
    Departments of Endocrinology and Diabetology, Otorhinolaryngology and Head and Neck Surgery, and Neurosurgery, Karolinska Hospital, Stockholm.
    Hulting, Anna-Lena
    Departments of Endocrinology and Diabetology, Otorhinolaryngology and Head and Neck Surgery, and Neurosurgery, Karolinska Hospital, Stockholm.
    Lundblad, Lars
    Departments of Endocrinology and Diabetology, Otorhinolaryngology and Head and Neck Surgery, and Neurosurgery, Karolinska Hospital, Stockholm.
    Änggård, Anders
    von Holst, Hans
    Transsphenoidal surgery in Cushing disease: 10 years of experience in 34 consecutive cases2004In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 100, p. 634-638Article in journal (Refereed)
    Abstract [en]

    Object. Cushing disease is a rare disorder. Because of their small size the adrenocorticotropic hormone (ACTH)—producing tumors are often not detectable on neuroimaging studies. To obtain a cure with transsphenoidal surgery (TSS) may therefore be difficult. In this report the authors present 10 years of experience in the treatment of patients with Cushing disease who were followed up with the same protocol and treated by the same surgeon.

    Methods. Thirty-four patients, 26 of them female and eight of them male (mean age 40 years, range 13–74 years) were studied. All had obvious clinical signs and symptoms of Cushing syndrome. Magnetic resonance (MR) imaging was performed in all patients, and inferior petrosal sinus (IPS) sampling was done in 14.

    In 12 patients MR imaging indicated a pituitary tumor; 10 were microadenomas and two were macroadenomas. In six patients with no visible tumor, the results of IPS sampling supported the diagnosis. All patients underwent TSS; the mean follow-up duration was 6 ± 0.5 years. Selective adenomectomy was performed in 32 and hemihypophysectomy in the other two patients. A cure was obtained in 31 patients (91%) after one TSS and in two more patients after further TSS; one patient was not cured despite two TSSs and one underwent bilateral adrenalectomy. Disease recurrence was seen in two patients after 3 years, and they were successfully treated with stereotactic gamma knife surgery. Half of the patients had an ACTH deficiency postoperatively, whereas one third had other pituitary hormone insufficiencies. There were no serious complications attributable to the surgical intervention.

    Conclusions. Transsphenoidal surgery with selective adenomectomy is an effective and safe treatment for Cushing disease. In the patients presented in this study, the surgical outcome seemed to depend on careful preoperative evaluation and the surgeon's experience. For optimal results in this rare disease the authors therefore suggest that the endocrinological, radiological, and surgical procedures be coordinated in a specialized center.

  • 26.
    Jacobsson, Johan
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Qvarlander, Sara
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Comparison of the CSF dynamics between patients with idiopathic normal pressure hydrocephalus and healthy volunteers2019In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 131, no 4, p. 1018-1023Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Intracranial pressure (ICP), outflow resistance (Rout), and amplitude of cardiac-related ICP pulsations (AMPs) are established parameters to describe the CSF hydrodynamic system and are assumed, but not confirmed, to be disturbed in idiopathic normal pressure hydrocephalus (INPH). The aim of this study was to compare the CSF hydrodynamic profile between patients with INPH and healthy volunteers.

    METHODS: Sixty-two consecutive INPH patients (mean age 74 years) and 40 healthy volunteers (mean age 70 years) were included. Diagnosis was made by two independent neurologists who assessed patients’ history, neurological status, and MRI studies. A CSF dynamic investigation through the lumbar route was performed: ICP and other CSF dynamic variables were blinded to the neurologists during the diagnostic process and were not used for establishing the diagnosis of INPH.

    RESULTS: Rout was significantly higher in INPH (Rout 17.1 vs 11.1; p < 0.001), though a substantial number of INPH subjects had normal Rout. There were no differences between INPH patients and controls regarding ICP (mean 11.5 mm Hg). At resting pressure, there was a trend that AMP in INPH was increased (2.4 vs 2.0 mm Hg; p = 0.109). The relationship between AMP and ICP was that they shared the same slope, but the curve was significantly shifted to the left for INPH (reduced P0 [p < 0.05]; i.e., higher AMP for the same ICP).

    CONCLUSIONS: This study established that the CSF dynamic profile of INPH deviates from that of healthy volunteers and that INPH should thus be regarded as a disease in which intracranial hydrodynamics are part of the pathophysiology.

    Clinical trial registration no.: NCT01188382 (clinicaltrials.gov)

  • 27.
    Karlsson, Bengt
    et al.
    Natl Univ Singapore Hosp, Div Neurosurg, Dept Surg, Singapore, Singapore..
    Johansson, Arne V.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Yang, Huai-Che
    Vet Gen Hosp, Dept Neurosurg, Taipei, Taiwan..
    Jokura, Hidefumi
    Furukawa Seiryo Hosp, Jiro Suzuki Mem Gamma House, Osaki, Japan..
    Yamamoto, Masaaki
    Katsuta Hosp Mito GammaHouse, Ibaraki, Japan..
    Martinez-Alvarez, Roberto
    Ruber Int Hosp, Madrid, Spain..
    Kawagishi, Jun
    Furukawa Seiryo Hosp, Jiro Suzuki Mem Gamma House, Osaki, Japan..
    Guo, Wan-Yuo
    Vet Gen Hosp, Dept Radiol, Taipei, Taiwan..
    Beute, Guus
    ETZ Elizabeth, Tilburg, Netherlands..
    Pan, David H. C.
    Vet Gen Hosp, Dept Neurosurg, Taipei, Taiwan..
    Chung, Wen-Yuh
    Vet Gen Hosp, Dept Neurosurg, Taipei, Taiwan.;Vet Gen Hosp, Dept Radiol, Taipei, Taiwan..
    Soderman, Michael
    Karolinska Hosp, Stockholm, Sweden..
    Aiyama, Hitoshi
    Katsuta Hosp Mito GammaHouse, Ibaraki, Japan..
    Yeo, Tseng Tsai
    Natl Univ Singapore Hosp, Div Neurosurg, Dept Surg, Singapore, Singapore..
    A novel method to determine the natural course of unruptured brain arteriovenous malformations without the need for follow-up information2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 129, p. 10-16Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE There is a strong clinical need to accurately determine the average annual hemorrhage risk in unruptured brain arteriovenous malformations (AVMs). This need motivated the present initiative to use data from a uniquely large patient population and design a novel methodology to achieve a risk determination with unprecedented accuracy. The authors also aimed to determine the impact of sex, pregnancy, AVM volume, and location on the risk for AVM rupture. METHODS The present study does not consider any specific management of the AVMs, but only uses the age distribution for the first hemorrhage, the shape of which becomes universal for a sufficiently large set of patients. For this purpose, the authors collected observations, including age at first hemorrhage and AVM size and location, in 3425 patients. The average annual risk for hemorrhage could then be determined from the simple relation that the number of patients with their first hemorrhage at a specific age equals the risk for hemorrhage times the number of patients at risk at that age. For a subset of the patients, the information regarding occurrence of AVM hemorrhage after treatment of the first hemorrhage was used for further analysis of the influence on risk from AVM location and pregnancy. RESULTS The age distribution for the first AVM hemorrhage was used to determine the average annual risk for hemorrhage in unruptured AVMs at adult ages (25-60 years). It was concluded to be 3.1% +/- 0.2% and unrelated to AVM volume but influenced by its location, with the highest risk for centrally located AVMs. The hemorrhage risk was found to be significantly higher for females in their fertile years. CONCLUSIONS The present methodology allowed the authors to determine the average annual risk for the first AVM hemorrhage at 3.1% +/- 0.2% without the need for individual patient follow-up. This methodology has potential also for other similar types of investigations. The conclusion that centrally located AVMs carry a higher risk was confirmed by follow-up information. Follow-up information was also used to conclude that pregnancy causes a substantially greater AVM hemorrhage risk. The age distribution for AVM hemorrhage is incompatible with AVMs present at birth having the same hemorrhage risk as AVMs in adults. Plausibly, they instead develop in the early years of life, possibly with a lower hemorrhage risk during that time period.

  • 28.
    Larsson, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Israelsson, Hanna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Epilepsy, headache, and abdominal pain after shunt surgery for idiopathic normal pressure hydrocephalus: the INPH-CRasH study2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 128, no 6, p. 1674-1683Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Adverse events related to shunt surgery are common and might have a negative effect on outcome in patients with idiopathic normal pressure hydrocephalus (INPH). The authors' objectives were to establish the frequencies of epilepsy, headache, and abdominal pain and determine their impact on patient quality of life (QOL), in long-term follow-up after shunt surgery for INPH.

    METHODS One hundred seventy-six shunt-treated patients with INPH (mean age 74 years) and 368 age- and sex-matched controls from the population were included. The mean follow-up time after surgery was 21 months (range 6-45 months). Each participant answered a questionnaire regarding present frequency and severity of headache and abdominal pain. Confirmed diagnoses of epilepsy and all prescriptions for antiepileptic drugs (AEDs) before and after shunt surgery for INPH were gathered from national registries. Equivalent presurgical and postsurgical time periods were constructed for the controls based on the date of surgery (the division date for controls is referred to as virtual surgery). All registry data covered a mean period of 6 years (range 3-8 years) before surgery/virtual surgery and 4 years (range 2-6 years) after surgery/virtual surgery. Provoked epileptic seizures were excluded. Patient QOL was assessed with the EuroQoL 5-dimension 5-level instrument.

    RESULTS Epilepsy was more common in shunt-treated patients with INPH than in controls (4.5% vs 1.1%, respectively; p = 0.023), as was treatment with AEDs (14.8% vs 7.3%, respectively; p = 0.010). No difference was found between the populations before surgery/virtual surgery (epilepsy, 2.3% [INPH] vs 1.1% [control], p = 0.280; AED treatment, 8.5% [INPH] vs 5.4% [control], p = 0.235). New-onset epilepsy and new AED treatment after surgery/virtual surgery were more common in INPH (epilepsy, 2.3% [INPH] vs 0.0% [control], p = 0.011; AED, 8.5% [INPH] vs 3.3% [control], p = 0.015). At follow-up, more patients with INPH than controls experienced headache several times per month or more often (36.1% vs 11.6%, respectively; p < 0.001). Patients with INPH and unilateral headache had more right-sided headaches than controls (p = 0.038). Postural headache was experienced by 16% (n = 27 of 169) of the patients with INPH. Twenty percent (n = 35) of the patients with INPH had persistent abdominal pain. Headache was not correlated to lower QOL. The study was underpowered to draw conclusions regarding QOL in patients with INPH who had epilepsy and abdominal pain, but the finding of no net difference in mean QOL indicates that no correlation between them existed.

    CONCLUSIONS Epilepsy, headache, and abdominal pain are common in long-term follow-up in patients after shunt surgery for INPH and are more common among patients with INPH than in the general population. All adverse events, including mild and moderate ones, should be considered during postoperative follow-ups and in the development of new methods for shunt placement.

  • 29.
    Lenfeldt, Niklas
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology. Neurologi.
    Andersson, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Ågren-Wilsson, Aina
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology. Neurologi.
    Bergenheim, A Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery. Neurokirurgi.
    Koskinen, Lars-Owe D
    Neurokirurgi.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology. Neurologi.
    Cerebrospinal fluid pulse pressure method: a possible substitute for the examination of B waves2004In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 101, no 6, p. 944-950Article in journal (Refereed)
    Abstract [en]

    Object. The appearance of numerous B waves during intracranial pressure (ICP) registration in patients with idiopathic adult hydrocephalus syndrome (IAHS) is considered to predict good outcome after shunt surgery. The aim of this study was to describe which physical parameters of the cerebrospinal fluid (CSF) system B-waves reflect and to find a method that could replace long-term B-wave analysis.

    Methods. Ten patients with IAHS were subjected to long-term registration of ICP and a lumbar constant-pressure infusion test. The B-wave presence, CSF outflow resistance (Rout), and relative pulse pressure coefficient (RPPC) were assessed using computerized analysis. The RPPC was introduced as a parameter reflecting the joint effect of elastance and pulsatory volume changes on ICP and was determined by relating ICP pulse amplitudes to mean ICP.

    Conclusions. The B-wave presence on ICP registration correlates strongly with RPPC (r = 0.91, p < 0.001, 10 patients) but not with CSF Rout. This correlation indicates that B waves—like RPPC—primarily reflect the ability of the CSF system to reallocate and store liquid rather than absorb it. The RPPC-assessing lumbar short-term CSF pulse pressure method could replace the intracranial long-term B-wave analysis.

  • 30.
    Luciano, Mark G.
    et al.
    Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
    Dombrowski, Stephen M.
    Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
    Qvarlander, Sara
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
    El-Khoury, Serge
    Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
    Yang, Jun
    Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
    Thyagaraj, Suraj
    Department of Mechanical Engineering, The University of Akron, Ohio.
    Loth, Francis
    Department of Mechanical Engineering, The University of Akron, Ohio.
    Novel method for dynamic control of intracranial pressure2017In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 126, no 5, p. 1629-1640Article in journal (Refereed)
    Abstract [en]

    OBJECT Intracranial pressure (ICP) pulsations are generally considered a passive result of the pulsatility of blood flow. Active experimental modification of ICP pulsations would allow investigation of potential active effects on blood and CSF flow and potentially create a new platform for the treatment of acute and chronic low blood flow states as well as a method of CSF substance clearance and delivery. This study presents a novel method and device for altering the ICP waveform via cardiac-gated volume changes.

    METHODS The novel device used in this experiment (named Cadence) consists of a small air-filled inelastic balloon (approximately 1.0 ml) implanted into the intracranial space and connected to an external programmable pump, triggered by an R-wave detector. Balloons were implanted into the epidural space above 1 of the hemispheres of 19 canines for up to 10 hours. When activated, the balloons were programed to cyclically inflate with the cardiac cycle with variable delay, phase, and volume. The ICP response was measured in both hemispheres. Additionally, cerebral blood flow (heat diffusion and laser Doppler) was studied in 16 canines.

    RESULTS This system, depending on the inflation pattern of the balloon, allowed a flattening of the ICP waveform, increase in the ICP waveform amplitude, or phase shift of the wave. This occurred with small mean ICP changes, typically around ± 2 mm Hg (15%). Bilateral ICP effects were observed with activation of the device: balloon inflation at each systole increased the systolic ICP pulse (up to 16 mm Hg, 1200%) and deflation at systole decreased or even inverted the systolic ICP pulse (-0.5 to -19 mm Hg, -5% to -1600%) in a dose-(balloon volume) dependent fashion. No aphysiological or deleterious effects on systemic pressure (≤ ±10 mm Hg; 13% change in mean pressure) or cardiac rate (≤ ± 17 beats per minute; 16% change) were observed during up to 4 hours of balloon activity.

    CONCLUSIONS The results of these initial studies using an intracranially implanted, cardiac-gated, volume-oscillating balloon suggest the Cadence device can be used to modify ICP pulsations, without physiologically deleterious effects on mean ICP, systemic vascular effects, or brain injury. This device and technique may be used to study the role of ICP pulsatility in intracranial hemo- and hydrodynamic processes and introduces the creation of a potential platform of a cardiac-gated system for treatment of acute and chronic low blood flow states, and diseases requiring augmentation of CSF substance clearance or delivery.

  • 31. Lundberg, Johan
    et al.
    Johansson, Carina B.
    Jonsson, Stefan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Holmin, Staffan
    Access to the brain parenchyma using endovascular techniques and a micro-working channel2017In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 126, no 2, p. 511-517Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Several older studies report a low risk for parenchymal access to the CNS by surgical techniques. In more recent studies, including those with post-puncture CT scans, there are indications that the risk of bleeding might approach 8%. New therapies, such as those that use viral vectors, modified mRNA, or cell transplantation, will probably warrant more parenchymal access to the CNS. Other minimally invasive routes might then be tempting to explore. This study was designed in 2 parts to address the possibility of using the endovascular route. The first aim was to test the ability to create a parenchymal micro-working channel to the CNS in macaque monkeys through the vessel wall. Second, the biocompatibility of a device-associated, detached, distal securing plug that was made of nitinol was investigated in swine for 1 year. METHODS Trans-vessel wall intervention in the middle cerebral artery and associated cerebral parenchyma was performed in 4 rhesus macaque monkeys using a full clinical angiography suite. A contrast agent and methylene blue were injected to test the working channel and then detached at the distal end to act as a securing plug through the vessel wall. One-year follow-ups were also performed using angiography and histological analysis in 10 swine with 24 implants that were distributed in the external carotid artery tree. RESULTS The cerebral interventions were performed without acute bleeding. Both the contrast agent and methylene blue were infused into the brain parenchyma and subarachnoidal space via the endovascular micro-working channel (7 injections in 4 animals). In the 1-year follow-up period, the implant that was left in the external carotid vessel wall in the swine was covered by the endothelium, which was followed by dislodgement just outside the blood vessel with thin capsule formation. No stenosis in the artery was detected on 1-year angiography. The animals showed normal behavior and blood sample results during the follow-up period. This is the first histological demonstration of nitinol biocompatibility when the implant is positioned through an arterial wall and indicates that the trans-vessel wall technique is not comparable with stent placement and its ability to induce intimal hyperplasia and restenosis. CONCLUSIONS This study demonstrates that the trans-vessel wall technique is applicable to brain intervention in macaque monkeys, providing a micro-working channel for delivery or sampling. The long-term follow-up study of the detached device in swine showed no clinical or biochemical complications and a normal angiography appearance.

  • 32. Lundkvist, B
    et al.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Kristensen, B
    Fagerlund, M
    Koskinen, L O
    Malm, J
    Cerebrospinal fluid hydrodynamics after placement of a shunt with an antisiphon device: a long-term study.2001In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 94, no 5, p. 750-6Article in journal (Refereed)
    Abstract [en]

    OBJECT: Few studies have been performed to investigate the cerebrospinal fluid (CSF) hydrodynamic profile in patients with idiopathic adult hydrocephalus syndrome (IAHS) before and after shunt implantation. The authors compared the in vivo CSF hydrodynamic properties, including the degree of gravity-induced CSF flow, of a shunt with an antisiphon device with a standard shunt.

    METHODS: Twelve patients with IAHS underwent insertion of shunts with Delta valves. Clinical testing, magnetic resonance imaging, and CSF hydrodynamic investigations were conducted with intracranial pressure (ICP), gravity effect, and pressure-flow curve of the shunt estimated at baseline and at 3 and 12 months postoperatively. No shunt was revised. Despite postoperative clinical improvement in all patients who received Delta valves, the mean ICP was only moderately reduced (mean decrease at 3 months 0.3 kPa [p = 0.02], at 12 months 0.2 kPa [not significant]). Patients with the greatest increase in ICP preoperatively had the most pronounced decrease postoperatively. The hydrostatic effect of the Delta valves was significantly lower than with the Hakim shunts (0.1-0.2 kPa compared with 0.6 kPa). The increased conductance (that is, lowered resistance) was up to 14 times higher with the Delta valves compared with preoperative levels.

    CONCLUSIONS: The function of a CSF shunt may be more complicated than previously thought; the subcutaneous pressure acting on the antisiphon device can modify the shunt characteristics. A compensatory increase in CSF production may counteract the increased outflow through the shunt. The improved CSF outflow conductance may increase the intracranial compliance and thereby dampen a pathological ICP waveform.

  • 33.
    Marklund, Niklas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Bareyre, Florence M.
    Royo, Nicolas C.
    Thompson, Hilaire J.
    Mir, Anis K.
    Grady, Sean
    Schwab, Martin E.
    McIntosh, Tracy K.
    Cognitive outcome following brain injury and treatment with an inhibitor of Nogo-A in association with an attenuated downregulation of hippocampal growth-associated protein-43 expression2007In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 107, no 4, p. 844-853Article in journal (Refereed)
    Abstract [en]

    Object. Central nervous system axons regenerate poorly after traumatic brain injury (TBI), partly due to inhibitors such as the protein Nogo-A present in myelin. The authors evaluated the efficacy of anti-Nogo-A monoclonal antibody (mAb) 7B 12 administration on the neurobehavioral and cognitive outcome of rats following lateral fluid-percussion brain injury, characterized the penetration of the 7B 12 or control antibodies into target brain regions, and evaluated the effects of Nogo-A inhibition on hemispheric tissue loss and sprouting of uninjured motor tracts in the cervical cord. To elucidate a potential molecular response to Nogo-A inhibition, we evaluated the effects of 7B 12 on hippocampal GAP-43 expression. Methods. Beginning 24 hours after lateral fluid-percussion brain injury or sham injury in rats, the mAb 7B12 or control antibody was infused intracerebroventricularly over 14 days, and behavior was assessed over 4 weeks. Results. Immunoreactivity for 7B 12 or immunoglobulin G was detected in widespread brain regions at 1 and 3 weeks postinjury. The brain-injured animals treated with 7B12 showed improvement in cognitive function (p < 0.05) at 4 weeks but no improvement in neurological motor function from 1 to 4 weeks postinjury compared with brain-injured, vehicle-treated controls. The enhanced cognitive function following inhibition of Nogo-A was correlated with an attenuated postinjury downregulation of hippocampal GAP-43 expression (p < 0.05). Conclusions. Increased GAP-43 expression may be a novel molecular mechanism of the enhanced cognitive recovery mediated by Nogo-A inhibition after TBI in rats.

  • 34.
    Marklund, Niklas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Blennow, Kaj
    Zetterberg, Henrik
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Monitoring of brain interstitial total tau and beta amyloid proteins by microdialysis in patients with traumatic brain injury2009In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 110, no 6, p. 1227-1237Article in journal (Refereed)
    Abstract [en]

    OBJECT: Damage to axons contributes to postinjury disabilities and is commonly observed following traumatic brain injury (TBI). Traumatic brain injury is an important environmental risk factor for the development of Alzheimer disease (AD). In the present feasibility study, the aim was to use intracerebral microdialysis catheters with a high molecular cutoff membrane (100 kD) to harvest interstitial total tau (T-tau) and amyloid beta 1-42 (Abeta42) proteins, which are important biomarkers for axonal injury and for AD, following moderate-to-severe TBI.METHODS: Eight patients (5 men and 3 women) were included in the study; 5 of the patients had a focal/mixed TBI and 3 had a diffuse axonal injury (DAI). Following the bedside analysis of the routinely measured energy metabolic markers (that is, glucose, lactate/pyruvate ratio, glycerol, and glutamate), the remaining dialysate was pooled and two 12-hour samples per day were used to analyze T-tau and Abeta42 by enzyme-linked immunosorbent assay from Day 1 up to 8 days postinjury.RESULTS: The results show high levels of interstitial T-tau and Abeta42 postinjury. Patients with a predominantly focal lesion had higher interstitial T-tau levels than in the DAI group from Days 1 to 3 postinjury (p < 0.05). In contrast, patients with DAI had consistently higher Abeta42 levels when compared with patients with focal injury.CONCLUSIONS: These results suggest that monitoring of interstitial T-tau and Abeta42 by using microdialysis may be an important tool when evaluating the presence and role of axonal injury following TBI.

  • 35. Mattsson, Per
    et al.
    Aldskogius, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neuroanatomy.
    Svensson, Mikael
    Nimodipine-induced improved survival rate of facial motor neurons following intracranial transection of the facial nerve in the adult rat1999In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 90, no 4, p. 760-765Article in journal (Refereed)
    Abstract [en]

    OBJECT:

    Neuronal survival is an important factor in the achievement of functional restitution after peripheral nerve injuries. Intracranial tumors or trauma may cause patients to exhibit a temporary or permanent facial nerve palsy. Nimodipine, which acts as an antagonist to L-type voltage-gated calcium channels, has been shown to be neuroprotective in various lesion models of the central and peripheral nervous systems. The aim of the present study was to evaluate the effect of nimodipine on motor neuron survival in the facial motor nucleus following intracranial transection of the adult rat facial nerve.

    METHODS:

    The facial nerve was cut intracranially in the posterior cranial fossa. Nimodipine was administered orally preoperatively for 3 days and postoperatively for up to 1 month, after which the number of neuronal profiles was quantified. The glial reaction was studied in the facial nucleus for up to 1 month by using immunocytochemical analysis. There was a significantly larger proportion of surviving motor neurons 1 month postinjury in animals treated with nimodipine (61+/-6.7%) in comparison with untreated animals (26.8+/-11.3%). Immunocytochemical analysis showed an increase in the amount of OX42 (microglia), ED1 (macrophages), and anti-glial fibrillary acidic protein (astrocytes) ipsilateral to the nerve injury; however, there was no difference between the two experimental groups of animals 2 to 28 days after surgery.

    CONCLUSIONS:

    The authors propose a neuroprotective role for nimodipine, which may be useful as a "cranial nerve protective agent" following insults such as head injury or skull base surgery.

  • 36.
    Nyberg, Christoffer
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Karlsson, Torbjörn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Predictors of increased cumulative serum levels of the N-terminal prohormone of brain natriuretic peptide 4 days after acute spontaneous subarachnoid hemorrhage2014In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 120, no 3, p. 599-604Article in journal (Refereed)
    Abstract [en]

    Object. The rupture of an intracranial aneurysm is followed by increased intracranial pressure and decreased cerebral blood flow. A major systemic stress reaction follows, presumably to restore cerebral blood flow. However, this reaction can also cause adverse effects, including myocardial abnormalities, which are common and can be serious, and increased levels of natriuretic peptides, especially brain natriuretic peptide (BNP). The association of BNP with fluid and salt balance, vasospasm, brain ischemia, and cardiac injury has been studied but almost exclusively regarding events after admission. Brain natriuretic peptide has also been measured at various time points and analyzed in different ways statistically. The authors approached BNP measurement in a new way; they used the calculated area under the curve (AUC) for the first 4 days to quantitatively measure the BNP load during the first critical part of the disease state. Their rationale was a suspicion that early BNP load is a marker of the severity of the ictus and will influence the subsequent course of the disease by disturbing the fluid and salt balance. Methods. The study included 156 patients with acute spontaneous subarachnoid hemorrhage (SAH). Mean patient age was 59.8 +/- 11.2 years, and 105 (67%) of the patients were female. An aneurysm was found in 138 patients. A total of 82 aneurysms were treated by endovascular coiling, 50 were treated by surgery, and 6 were untreated. At the time of admission, serum samples were collected for troponin-I analysis and for the N-terminal prohormone of BNP (NT-proBNP); daily thereafter, samples were collected for the NT-proBNP analysis. The cumulative BNP load was calculated as the AUC for NT-proBNP during the first 4 days. The following variables were studied in terms of their influence on the AUC for NT-proBNP: sex, age, World Federation of Neurosurgical Societies grade of SAH, Fisher grade, angiographic result, treatment of aneurysm,'clinical neurological deterioration, verified infections, vasospasm treatment, and 6-month outcome. Results. The AUC for NT-proBNP was larger when variables indicated a more severe SAH. These variables were higher Fisher and World Federation of Neurosurgical Societies grades, high levels of troponin-I at admission, an aneurysm, neurological deficits, and infections. The AUC for NT-proBNP was also larger among women, older patients, and patients with poor outcomes. Linear regression showed that the best predicting model for large AUC for NT-proBNP was the combination of the following: female sex, high levels of troponin-I, an aneurysm, neurological deficits, and advanced age. Conclusions. The cumulative BNP load during the first days after SAH can be predicted by variables describing the severity of the disease already known at the time of admission. This information can be used to identify patients at risk for an adverse course of the disease.

  • 37. Olivecrona, Magnus
    et al.
    Wildemyr, Zandra
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Koskinen, Lars-Owe D.
    The apolipoprotein E epsilon 4 allele and outcome in severe traumatic brain injury treated by an intracranial pressure-targeted therapy2010In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 112, no 5, p. 1113-1119Article in journal (Refereed)
    Abstract [en]

    Object. In this paper, the authors' goal was to study the influence of the apolipoprotein E epsilon 4 allele on the clinical outcome in patients treated for severe traumatic brain injury (TBI) with an intracranial pressure (ICP)-targeted therapy based on the Lund concept. Methods. The authors conducted a prospective double-blinded randomized trial in which they examined patients with severe TBI. Inclusion criteria consisted of a Glasgow Coma Scale (GCS) score <= 8 at the time of intubation and sedation, patient age between 15 and 70 years, an initial cerebral perfusion pressure > 10 mm Hg, and arrival to the hospital < 24 hours after trauma. Blood samples for the analysis of apolipoprotein E allele types were collected. Independent staff members evaluated outcomes by obtaining Glasgow Outcome Scale (GOS) scores at 3, 12, and 24 months. Results. The occurrence of the epsilon 4 allele was analyzed in 46 patients (mean age 35 +/- 2.2 years with a median GCS score of 6 [range 3-8]). The epsilon 4 allele was present in 39.1% of the patients. The ICP, cerebral perfusion pressure, and injury severity score were not statistically significantly different between the groups. The median GOS score at 3 months was 3.5, and at 12 and 24 months was 4 (range 1-5). Except for the GOS score at 3 months, which was dichotomized as favorable (GOS Score 4 or 5) and unfavorable (GOS Scores 1-3), no statistically significant differences in outcome, irrespective of GOS dichotomization used, were found between the patients with the epsilon 4 allele and those without. The presence of the epsilon 4 allele did not predict for clinical outcome, but GCS and ICP did. Conclusions. The presence of epsilon 4 is not associated with long-term clinical outcome in patients with severe TBI treated with an ICP targeted therapy, based on the Lund concept.

  • 38.
    Olivecrona, Magnus
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Wildemyr, Zandra
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Koskinen, Lars-Owe D
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    The apolipoprotein E epsilon4 allele and outcome in severe traumatic brain injury treated by an intracranial pressure-targeted therapy2010In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 112, no 5, p. 1113-1119Article in journal (Refereed)
    Abstract [en]

    The presence of epsilon4 is not associated with long-term clinical outcome in patients with severe TBI treated with an ICP targeted therapy, based on the Lund concept.

  • 39.
    Olivecrona, Magnus
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Zetterlund, Bo
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neurophysiology.
    Rodling-Wahlström, Marie
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Naredi, Silvana
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Koskinen, Lars-Owe D
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Absence of electroencephalographic seizure activity in patients treated for head injury with an ICP targeted therapy2009In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 110, no 2, p. 300-305Article in journal (Refereed)
    Abstract [en]

    OBJECT: The authors prospectively studied the occurrence of clinical and nonclinical electroencephalographically verified seizures during treatment with an intracranial pressure (ICP)-targeted protocol in patients with traumatic brain injury (TBI). METHODS: All patients treated for TBI at the Department of Neurosurgery, University Hospital Umea, Sweden, were eligible for the study. The inclusion was consecutive and based on the availability of the electroencephalographic (EEG) monitoring equipment. Patients were included irrespective of pupil size, pupil reaction, or level of consciousness as long as their first measured cerebral perfusion pressure was > 10 mm Hg. The patients were treated in a protocol-guided manner with an ICP-targeted treatment based on the Lund concept. The patients were continuously sedated with midazolam, fentanyl, propofol, or thiopental, or combinations thereof. Five-lead continuous EEG monitoring was performed with the electrodes at F3, F4, P3, P4, and a midline reference. Sensitivity was set at 100 muV per cm and filter settings 0.5-70 Hz. Amplitude-integrated EEG recording and relative band power trends were displayed. The trends were analyzed offline by trained clinical neurophysiologists. RESULTS: Forty-seven patients (mean age 40 years) were studied. Their median Glasgow Coma Scale score at the time of sedation and intubation was 6 (range 3-15). In 8.5% of the patients clinical seizures were observed before sedation and intubation. Continuous EEG monitoring was performed for a total of 7334 hours. During this time neither EEG nor clinical seizures were observed. CONCLUSIONS: Our protocol-guided ICP targeted treatment seems to protect patients with severe TBI from clinical and subclinical seizures and thus reduces the risk of secondary brain injury.

  • 40. Pepper, Joshua
    et al.
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, Queen Square, London.
    Zrinzo, Ludvic
    Anterior capsulotomy and deep brain stimulation Response2015In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 122, no 5, p. 1026-1027Article in journal (Other academic)
  • 41. Pepper, Joshua
    et al.
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Unit of Functional Neurosurgery, University College London Institute of Neurology, Queen Square, UK.
    Zrinzo, Ludvic
    Deep brain stimulation versus anterior capsulotomy for obsessive-compulsive disorder: a review of the literature2015In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 122, no 5, p. 1028-1037Article, review/survey (Refereed)
    Abstract [en]

    Obsessive-compulsive disorder (OCD) is a chronic and debilitating psychiatric condition. Traditionally, anterior capsulotomy (AC) was an established procedure for treatment of patients with refractory OCD. Over recent decades, deep brain stimulation (DBS) has gained popularity. In this paper the authors review the published literature and compare the outcome of AC and DBS targeting of the area of the ventral capsule/ventral striatum (VC/VS) and nucleus accumbens (NAcc). Patients in published cases were grouped according to whether they received AC or DBS and according to their preoperative scores on the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and then separated according to outcome measures: remission (YBOCS score < 8); response (>= 35% improvement in YBOCS score); nonresponse (<35% improvement in YBOCS score); and unfavorable (i.e., worsening of the baseline YBOCS score). Twenty studies were identified reporting on 170 patients; 62 patients underwent DBS of the VC/VS or the NAcc (mean age 38 years, follow-up 19 months, baseline YBOCS score of 33), and 108 patients underwent AC (mean age 36 years, follow-up 61 months, baseline YBOCS score of 30). In patients treated with DBS there was a 40% decrease in YBOCS score, compared with a 51% decrease for those who underwent AC (p = 0.004). Patients who underwent AC were 9% more likely to go into remission than patients treated with DBS (p = 0.02). No difference in complication rates was noted. Anterior capsulotomy is an efficient procedure for refractory OCD. Deep brain stimulation in the VC/VS and NAcc area is an emerging and promising therapy. The current popularity of DBS over ablative surgery for OCD is not due to nonefficacy of AC, but possibly because DBS is perceived as more acceptable by clinicians and patients.

  • 42. Pepper, Joshua
    et al.
    Meliak, Lara
    Akram, Harith
    Hyam, Jonathan
    Milabo, Catherine
    Candelario, Joseph
    Foltynie, Thomas
    Limousin, Patricia
    Curtis, Carmel
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. UCL, Unit Funct Neurosurg, Inst Neurol, Queen Sq, London, England.
    Zrinzo, Ludvic
    Changing of the guard: reducing infection when replacing neural pacemakers2017In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 126, no 4, p. 1165-1172Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Infection of deep brain stimulation (DBS) hardware has a significant impact on patient morbidity. Previous experience suggests that infection rates appear to be higher after implantable pulse generator (IPG) replacement surgery than after the de novo DBS procedure. In this study the authors examine the effect of a change in practice during DBS IPG replacements at their institution. METHODS Starting in January 2012, patient screening for methicillin-resistant Staphylococcus aureus (MRSA) and, and where necessary, eradication was performed prior to elective DBS IPG change. Moreover, topical vancomycin was placed in the IPG pocket during surgery. The authors then prospectively examined the infection rate in patients undergoing DBS IPG replacement at their center over a 3-year period with at least 9 months of follow-up. RESULTS The total incidence of infection in this prospective consecutive series of 101 IPG replacement procedures was 0%, with a mean follow-up duration of 24 +/- 11 months. This was significantly lower than the authors' previously published historical control group, prior to implementing the change in practice, where the infection rate for IPG replacement was 8.5% (8/94 procedures; p = 0.003). CONCLUSIONS This study suggests that a change in clinical practice can significantly lower infection rates in patients undergoing DBS IPG replacement. These simple measures can minimize unnecessary surgery, loss of benefit from chronic stimulation, and costly hardware replacement, further improving the cost efficacy of DBS therapies.

  • 43. Pepper, Joshua
    et al.
    Meliak, Lara
    Akram, Harith
    Hyam, Jonathan
    Milabo, Catherine
    Candelario, Joseph
    Foltynie, Thomas
    Limousin, Patricia
    Curtis, Carmel
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Unit of Functional Neurosurgery, University College London Institute of Neurology, Queen Square, London.
    Zrinzo, Ludvic
    Changing of the guard: reducing infection when replacing neural pacemakers2017In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 126, no 4, p. 1165-1172Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Infection of deep brain stimulation (DBS) hardware has a significant impact on patient morbidity. Previous experience suggests that infection rates appear to be higher after implantable pulse generator (IPG) replacement surgery than after the de novo DBS procedure. In this study the authors examine the effect of a change in practice during DBS IPG replacements at their institution. METHODS Starting in January 2012, patient screening for methicillin-resistant Staphylococcus aureus (MRSA) and, and where necessary, eradication was performed prior to elective DBS IPG change. Moreover, topical vancomycin was placed in the IPG pocket during surgery. The authors then prospectively examined the infection rate in patients undergoing DBS IPG replacement at their center over a 3-year period with at least 9 months of follow-up. RESULTS The total incidence of infection in this prospective consecutive series of 101 IPG replacement procedures was 0%, with a mean follow-up duration of 24 ± 11 months. This was significantly lower than the authors' previously published historical control group, prior to implementing the change in practice, where the infection rate for IPG replacement was 8.5% (8/94 procedures; p = 0.003). CONCLUSIONS This study suggests that a change in clinical practice can significantly lower infection rates in patients undergoing DBS IPG replacement. These simple measures can minimize unnecessary surgery, loss of benefit from chronic stimulation, and costly hardware replacement, further improving the cost efficacy of DBS therapies.

  • 44.
    Rossitti, Sandro
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery.
    Letter: Creative use of endovascular devices in cerebral aneurysm treatment in JOURNAL OF NEUROSURGERY, vol 121, issue 5, pp 1285-12852014In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 121, no 5, p. 1285-1285Article in journal (Other academic)
    Abstract [en]

    n/a

  • 45.
    Rossitti, Sandro
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Neurosurgery. Linköping University, Faculty of Medicine and Health Sciences.
    Letter: The blood-hammer effect and aneurysmal basilar artery bifurcation angles in JOURNAL OF NEUROSURGERY2015In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 122, no 6, p. 1512-1513Article in journal (Other academic)
    Abstract [en]

    n/a

  • 46.
    Rostami, Elham
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Engquist, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Johnson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nilsson, Pelle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Early low cerebral blood flow and high cerebral lactate: prediction of delayed cerebral ischemia in subarachnoid hemorrhage2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 128, no 6, p. 1762-1770Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH) is one of the major contributors to poor outcome. It is crucial to be able to detect early signs of DCI to prevent its occurrence. The objective of this study was to determine if low cerebral blood flow (CBF) measurements and pathological microdialysis parameters measured at the bedside can be observed early in patients with SAH who later developed DCI. METHODS The authors included 30 patients with severe SAH. The CBF measurements were performed at Day 0-3 after disease onset, using bedside xenon-CT. Interstitial glucose, lactate, pyruvate, glycerol, and glutamate were measured using microdialysis. RESULTS Nine of 30 patients developed DCI. Patients with DCI showed significantly lower global and regional CBF, and lactate was significantly increased in these patients. A high lactate/pyruvate ratio was also detected in patients with DCI. CONCLUSIONS Early low CBF measurements and a high lactate and lactate/pyruvate ratio may be early warning signs of the risk of developing DCI. The clinical value of these findings needs to be confirmed in larger studies.

  • 47.
    Samuelsson, Carolina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Relationship between intracranial hemodynamics and microdialysis markers of energy metabolism and glutamate-glutamine turnover in patients with subarachnoid hemorrhage2009In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 111, no 5, p. 910-915Article in journal (Refereed)
    Abstract [en]

    OBJECT: The aim of this study was to explore the relationship between hemodynamics (intracranial and systemic) and brain tissue energy metabolism, and between hemodynamics and glutamate (Glt)-glutamine (Gln) cycle activity. METHODS: Brain interstitial levels of lactate, pyruvate, Glt, and Gln were prospectively monitored in the neurointensive care unit for more than 3600 hours using intracerebral microdialysis in 33 patients with subarachnoid hemorrhage (SAH). Intracranial pressure (ICP), mean arterial blood pressure, and cerebral perfusion pressure (CPP) were recorded using a digitalized system. RESULTS: Interstitial Gln and pyruvate correlated with CPP (r = 0.25 and 0.24, respectively). Intracranial pressure negatively correlated with Gln (r = -0.29) and the Gln/Glt ratio (r = -0.40). Levels of Gln and pyruvate and the Gln/Glt ratio were higher and levels of Glt and lactate and the lactate/pyruvate ratio were lower during periods of decreased ICP (<or= 10 mm Hg) as compared with values in periods of elevated ICP (> 10 mm Hg). In 3 patients, a poor clinical condition was attributed to high ICP levels (range 15-25 mm Hg). When CSF drainage was increased and the ICP was lowered to 10 mm Hg, there was an instantaneous sharp increase in interstitial Glt and pyruvate in these 3 patients. CONCLUSIONS: Increasing interstitial Gln and pyruvate levels appear to be favorable signs associated with improved CPP and low ICP. The authors suggest that this pattern indicates an energy metabolic situation allowing augmented astrocytic energy metabolism with accelerated Glt uptake and Gln synthesis. Moreover, their data raised the question of whether patients with SAH and moderately elevated ICP (15-20 mm Hg) would benefit from CSF drainage at lower pressure levels than what is usually indicated in current clinical protocols.

  • 48.
    Samuelsson, Carolina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Response2009In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 111, no 5, p. 908-909Article in journal (Refereed)
  • 49.
    Sundblom, Jimmy
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nowinski, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Casar Borota, Olivera
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology.
    Ryttlefors, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Removal of giant intraosseous meningioma followed by cranioplasty using a custom-made bioceramic implant: case report2019In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 131, no 3, p. 735-739Article in journal (Refereed)
    Abstract [en]

    Intraosseous meningioma of the chordoid type is a rare clinical entity. Radical surgical removal and subsequent cranioplasty is the treatment of choice. Here, the authors report a severe case involving more than 70% of the calvarial surface area, which was removed and repaired using a prefabricated custom-made, titanium-reinforced, bioceramic implant and bone-cutting guides. Tumor removal and good esthetic outcome were achieved, along with a 17.1% increase of intracranial volume. Bioceramic implants have shown promising initial results and may represent an important new tool in the surgeon's armamentarium.

  • 50.
    Sundström, Nina
    et al.
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Andersson, Kennet
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Marmarou, Anthony
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Comparison between 3 infusion methods to measure cerebrospinal fluid outflow conductance2010In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 113, no 6, p. 1294-1303Article in journal (Refereed)
    Abstract [en]

    Object There are several infusion methods available to estimate the outflow conductance (Cout) or outflow resistance (Rout = 1/Cout) of the CSF system. It has been stated that for unknown reasons, the bolus infusion method estimates a higher Cout than steady-state infusion methods. The aim of this study was to compare different infusion methods for estimation of Cout.

    Methods The following 3 different infusion methods were used: the bolus infusion method (Cout bol); the constant flow infusion method, both static (Cout stat) and dynamic (Cout dyn) analyses; and the constant pressure infusion method (Cout cpi). Repeated investigations were performed on an experimental model with well-known characteristics, with and without physiological pressure variations (B-waves, breathing, and so on). All 3 methods were also performed in a randomized order during the same investigation in 20 patients with probable or possible idiopathic normal-pressure hydrocephalus; 6 of these patients had a shunt and 14 did not.

    Results Without the presence of physiological pressure variations, the concordance in the experimental model was good between all methods. When they were added, the repeatability was better for the steady-state methods and a significantly higher Cout was found with the bolus method in the region of clinically relevant Cout (p < 0.05). The visual fit for the bolus infusion was dependent on subjective assessment by the operator. This experimental finding was confirmed by the clinical results, where significant differences were found in the investigations in patients without shunts between Cout of the visual bolus method and Cout stat, Cout dyn, and Cout cpi (4.58, 4.18, and 6.12 μl/[second × kPa], respectively).

    Conclusions This study emphasized the necessity for standardization of Cout measurements. An experienced operator could partly compensate for difficulties in correctly estimating the pressure parameters for the bolus infusion method, but for the general user this study suggests a steady-state method for estimating Cout.

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