| 1. |
- Ambarki, Khalid, et al.
(författare)
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Brain ventricular size in healthy elderly: comparison between evans index and volume measurement.
- 2010
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Ingår i: Neurosurgery. - : Lippincott Williams & Wilkins. - 0148-396X .- 1524-4040. ; 67:1, s. 94-99
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A precise definition of ventricular enlargement is important in the diagnosis of hydrocephalus as well as in assessing central atrophy. The Evans index (EI), a linear ratio between the maximal frontal horn width and the cranium diameter, has been extensively used as an indirect marker of ventricular volume (VV). With modern imaging techniques, brain volume can be directly measured. OBJECTIVE: To determine reference values of intracranial volumes in healthy elderly individuals and to correlate volumes with the EI. METHODS: Magnetic resonance imaging (3 T) was performed in 46 healthy white elderly subjects (mean age +/- standard deviation, 71 +/- 6 years) and in 20 patients (74 +/- 7 years) with large ventricles according to visual inspection. VV, relative VV (RVV), and EI were assessed. Ventricular dilation was defined using VV and EI by a value above the 95th percentile range for healthy elderly individuals. RESULTS: In healthy elderly subjects, we found VV = 37 +/- 18 mL, RVV = 2.47 +/- 1.17%, and EI = 0.281 +/- 0.027. Including the patients, there was a strong correlation between EI and VV (R = 0.94) as well as between EI and RVV (R = 0.95). However, because of a wide 95% prediction interval (VV: +/-45 mL; RVV: +/- 2.54%), EI did not give a sufficiently good estimate of VV and RVV. CONCLUSION: VV (or RVV) and the EI reflect different properties. The exclusive use of EI in clinical studies as a marker of enlarged ventricles should be questioned. We suggest that the definition of dilated ventricles in white elderly individuals be defined as VV >77 mL or RVV >4.96 %. Future studies should compare intracranial volumes with clinical characteristics and prognosis.
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| 2. |
- Basma, Jaafar, et al.
(författare)
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Mobilization of the Transcavernous Oculomotor Nerve During Basilar Aneurysm Surgery : Biomechanical Bases for Better Outcome
- 2014
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 10:1, s. 106-114
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The transcavernous approach adds a significant exposure advantage in basilar aneurysm surgery. However, one of its frequently reported side effects is postoperative oculomotor nerve palsy. OBJECTIVE: To present the technique of mobilizing the oculomotor nerve throughout its intracranial course and to analyze its consequences on the nerve tension and clinical outcome. METHODS: The oculomotor nerve is mobilized from its mesencephalic origin to the superior orbital fissure. Its degree of mobility, related to the imposed pulling force, was measured in 11 cadaveric nerves. Tension was mathematically deduced and compared before and after mobilizing of the cavernous segment. One hundred four patients treated for basilar aneurysms with the orbitozygomatic pretemporal transcavernous approach were followed up for a 1-year period and evaluated for postoperative oculomotor nerve palsy. RESULTS: Releasing the transcavernous segment compared to cisternal mobilization alone resulted in a significant increase in freedom of mobility from 4 to 7.9 mm (P < .001) and in a significant decrease in tension from 0.8 to 0.5 N (P = .006). Ninety-nine percent of aneurysms treated with this technique were amenable to neck clipping, and a total of 84% of patients had a good postoperative outcome (modified Rankin Scale score, 0-2). All patients showed direct postoperative palsy; however, 97% had a complete recovery by 9 months. Only 3 patients had a persistent diplopia on medial gaze, which was corrected with prism glasses. CONCLUSION: Mobilization of the transcavernous oculomotor nerve results in better maneuverability and less tension on the nerve, which lead to successful surgical treatment and favorable oculomotor outcome.
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| 3. |
- Behrens, Anders, et al.
(författare)
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In Reply
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 67:6, s. 1864-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 4. |
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| 5. |
- Behrens, Anders, et al.
(författare)
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Transcranial Doppler pulsatility index: not an accurate method to assess intracranial pressure.
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 66:6, s. 1050-1057
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transcranial Doppler sonography (TCD) assessment of intracranial blood flow velocity has been suggested to accurately determine intracranial pressure (ICP). OBJECTIVE: We attempted to validate this method in patients with communicating cerebrospinal fluid systems using predetermined pressure levels. METHODS: Ten patients underwent a lumbar infusion test, applying 4 to 5 preset ICP levels. On each level, the pulsatility index (PI) in the middle cerebral artery was determined by measuring the blood flow velocity using TCD. ICP was simultaneously measured with an intraparenchymal sensor. ICP and PI were compared using correlation analysis. For further understanding of the ICP-PI relationship, a mathematical model of the intracranial dynamics was simulated using a computer. RESULTS: The ICP-PI regression equation was based on data from 8 patients. For 2 patients, no audible Doppler signal was obtained. The equation was ICP = 23*PI + 14 (R = 0.22, P < .01, N = 35). The 95% confidence interval for a mean ICP of 20 mm Hg was -3.8 to 43.8 mm Hg. Individually, the regression coefficients varied from 42 to 90 and the offsets from -32 to +3. The mathematical simulations suggest that variations in vessel compliance, autoregulation, and arterial pressure have a serious effect on the ICP-PI relationship. CONCLUSIONS: The in vivo results show that PI is not a reliable predictor of ICP. Mathematical simulations indicate that this is caused by variations in physiological parameters.
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| 6. |
- Holl, Etienne M, et al.
(författare)
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Improving targeting in image-guided frame-based deep brain stimulation
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 67:2 Suppl, s. ons437-ons447
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Tidskriftsartikel (refereegranskat)abstract
- After calibration of a systematic targeting error an MR image-guided stereotactic approach would be expected to deliver 97% of all electrodes to within 2 mm of the intended target point with a single brain pass.
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| 7. |
- Johnson, Ulf, et al.
(författare)
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Favorable Outcome in Traumatic Brain Injury Patients With Impaired Cerebral Pressure Autoregulation When Treated at Low Cerebral Perfusion Pressure Levels
- 2011
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 68:3, s. 714-721
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cerebral pressure autoregulation (CPA) is defined as the ability of the brain vasculature to maintain a constant blood flow over a range of different systemic blood pressures by means of contraction and dilatation. OBJECTIVE: To study CPA in relation to physiological parameters, treatment, and outcome in a series of traumatic brain injury patients. METHODS: In this prospective observational study, 44 male and 14 female patients (age, 15-72 years; mean, 38.7 years; Glasgow Coma Scale score, 4-13; median, 7) were analyzed. Patients were divided into groups on the basis of status of CPA (more pressure active vs more pressure passive) and level of cerebral perfusion pressure (CPP; low vs high CPP). The proportions of favorable outcome in the groups were assessed. Differences in physiological variables in the different groups were analyzed. RESULTS: Patients with more impaired CPA treated at CPP levels below median had a significantly higher proportion of favorable outcome compared with patients with more impaired CPA treated at CPP levels above median. No significant difference in outcome was seen between patients with more intact CPA when divided by level of CPP. In patients with more impaired CPA, CPP < 50 mm Hg and CPP < 60 mm Hg were associated with favorable outcome, whereas CPP > 70 mm Hg and CPP > 80 mm Hg were associated with unfavorable outcome. In patients with more intact CPA, no difference in physiological variables was seen between patients with favorable and unfavorable outcomes. CONCLUSION: Our results support that in traumatic brain injury patients with impaired CPA, CPP should not be elevated.
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| 8. |
- Koivisto, Anne M, et al.
(författare)
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Poor Cognitive Outcome in Shunt-Responsive Idiopathic Normal Pressure Hydrocephalus
- 2013
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 72:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:: Idiopathic normal pressure hydrocephalus (iNPH) causes cognitive decline that can be alleviated by shunting, but long-term outcome studies are scarce. OBJECTIVE:: To elucidate the long-term cognitive condition of shunt-responsive iNPH patients. METHODS:: The follow-up data (Kuopio University Hospital NPH Registry) of 146 patients diagnosed with iNPH by clinical and radiological examination, 24-hour intraventricular pressure monitoring, frontal cortical biopsy, and response to the shunt were analyzed for signs of dementia. The Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition, and specified memory disorder criteria were used. Median follow-up was 4.8 years. RESULTS:: At the end of follow-up, 117 (80%) of the 146 iNPH patients had cognitive decline and 67 (46%) had clinical dementia. The most common clinical diagnoses were Alzheimer disease and vascular dementia. In multivariate analysis of the 146 iNPH patients, memory deficit as a first symptom before shunt (odds ratio [OR] 18.3; 95% confidence interval [CI] 1.9-175), male sex (OR 3.29; 95% CI 1.11-9.73), age (OR 1.17 year; 95% CI 1.07-1.28), and follow-up time (OR 1.20 year; 95% CI 1.02-1.40) predicted dementia. Interestingly, 8 (5%) iNPH patients had dementia without any signs of other neurodegenerative diseases in clinical, neuroradiological, or brain biopsy evaluation. These patients initially presented a full triad of symptoms, with gait disturbance being the most frequent initial symptom followed by deterioration in cognition. CONCLUSION:: The novel findings were (a) a significant risk of dementia in iNPH initially responsive to cerebrospinal fluid shunt, (b) cognitive impairment most commonly due to iNPH-related dementia followed by concurrent degenerative brain disease, and (c) a subgroup with dementia related to iNPH without comorbidities. ABBREVIATIONS:: Aβ, amyloid betaAD, Alzheimer diseaseCI, confidence intervalHPτ, hyperphosphorylated tauICP, intracranial pressureiNPH, idiopathic normal pressure hydrocephalusKUH, Kuopio University HospitalNPH, normal pressure hydrocephalusVaD, vascular dementia.
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| 9. |
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| 10. |
- Lenfeldt, Niklas, et al.
(författare)
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Diffusion tensor imaging reveals supplementary lesions to frontal white matter in Idiopathic normal pressure hydrocephalus
- 2011
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 68:6, s. 1586-1593
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:: Idiopathic normal pressure hydrocephalus (INPH) is associated with white matter lesions, but the extent and severity of the lesions do not cohere with symptoms or improvement after shunting, implying the presence of further, yet undisclosed, injuries to white matter in INPH. OBJECTIVE:: To apply diffusion tensor imaging (DTI) to explore white matter lesions in patients with INPH before and after drainage of cerebrospinal fluid (CSF). METHODS:: Eighteen patients and ten controls were included. DTI was performed in a 1.5T MRI scanner before and after three-day drainage of 400 ml of CSF. Regions of interest included corpus callosum, capsula interna, frontal and lateral periventricular white matter, and centrum semiovale. White matter integrity was quantified by assessing fractional anisotropies (FA) and apparent diffusion coefficients (ADC), comparing them between patients and controls and between patients before and after drainage. The significance level corresponded to 0.05 (Bonferroni corrected). RESULTS:: Decreased FA in patients was found in three regions (p<0.002, p<0.001 and p<0.0001) in anterior frontal white matter, whereas elevated ADC was found in genu corpus callosum (p<0.0001) and areas of centrum semiovale associated to the precentral gyri (p<0.002). Diffusion patterns in these areas did not change after drainage. CONCLUSION:: DTI reveals subtle injuries - interpreted as axonal loss and gliosis - to anterior frontal white matter where high-order motor systems between frontal cortex and basal ganglia travel, further supporting the notion that motor symptoms in INPH are caused by a chronic ischemia to the neuronal systems involved in the planning processes of movements.
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| 11. |
- Mondello, Stefania, et al.
(författare)
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Clinical utility of serum levels of ubiquitin C-terminal hydrolase as a biomarker for severe traumatic brain injury
- 2012
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Ingår i: Neurosurgery. - : Wolters Kluwer. - 0148-396X .- 1524-4040. ; 70:3, s. 666-675
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Tidskriftsartikel (refereegranskat)abstract
- Background: Brain damage markers released in cerebrospinal fluid (CSF) and blood may provide valuable information about diagnosis and outcome prediction after traumatic brain injury (TBI).Objective: To examine the concentrations of ubiquitin C-terminal hydrolase-L1 (UCH-L1), a novel brain injury biomarker, in CSF and serum of severe TBI patients and their association with clinical characteristics and outcome.Methods: This case-control study enrolled 95 severe TBI subjects (Glasgow Coma Scale [GCS] score, 8). Using sensitive UCH-L1 sandwich ELISA, we studied the temporal profile of CSF and serum UCH-L1 levels over 7 days for severe TBI patients.Results: Comparison of serum and CSF levels of UCH-L1 in TBI patients and control subjects shows a robust and significant elevation of UCH-L1 in the acute phase and over the 7-day study period. Serum and CSF UCH-L1 receiver-operating characteristic curves further confirm strong specificity and selectivity for diagnosing severe TBI vs controls, with area under the curve values in serum and CSF statistically significant at all time points up to 24 hours (P < .001). The first 12-hour levels of both serum and CSF UCH-L1 in patients with GCS score of 3 to 5 were also significantly higher than those with GCS score of 6 to 8. Furthermore, UCH-L1 levels in CSF and serum appear to distinguish severe TBI survivors from nonsurvivors within the study, with nonsurvivors having significantly higher and more persistent levels of serum and CSF UCH-L1. Cumulative serum UCH-L1 levels > 5.22 ng/mL predicted death (odds ratio, 4.8).Conclusion: Serum levels of UCH-L1 appear to have potential clinical utility in diagnosing TBI, including correlating to injury severity and survival outcome.
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| 12. |
- Petersen, Erika A, et al.
(författare)
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Minimizing brain shift in stereotactic functional neurosurgery
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 67:3 Suppl, s. ons213-ons221
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Tidskriftsartikel (refereegranskat)abstract
- Brain shift has long been considered an issue in stereotactic targeting during DBS procedures. However, with the image-guided approach and surgical technique used in this study, subcortical brain shift was extremely limited and did not appear to adversely affect clinical outcome.
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| 13. |
- Ryttlefors, Mats, et al.
(författare)
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Patient age and vasospasm after subarachnoid hemorrhage
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 67:4, s. 911-917
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Subarachnoid hemorrhage (SAH) from a ruptured intracranial aneurysm is a devastating disease with high mortality and morbidity. The incidence of SAH increases with advancing age. OBJECTIVE: To determine whether age is an independent predictor of angiographic vasospasm, delayed ischemic neurological deficits (DINDs), or abnormal transcranial Doppler (TCD) measurements in patients with aneurysmal subarachnoid hemorrhage. METHODS: Data from CONSCIOUS-1 (Clazosentan to Overcome Neurological Ischemia and Infarct Occurring After Subarachnoid Hemorrhage study), a dose-finding study of clazosentan, were used. Data on angiographic vasospasm, DINDs, and TCD abnormalities were prospectively recorded as well as baseline characteristics and treatment data. Patient age was considered in 3 ways: as a continuous variable, dichotomized at age 65 years, and categorized by decade. Age was investigated as the main variable, whereas other possible confounding variables were adjusted for in the multiple logistic regression modeling with each of 3 dichotomized vasospasm outcome measures, presence or absence of angiographic vasospasm, DINDs, and TCD abnormalities as the dependent variable. RESULTS: The proportions of patients with angiographic vasospasm, DINDs, and TCD abnormalities were 45%, 19%, and 81%, respectively. Age, whether considered as a continuous, dichotomous, or a categorical variable, was not significantly associated with angiographic vasospasm, DINDs, or abnormal TCD measurements. CONCLUSION: Age does not seem to be a significant predictor for cerebral vasospasm after subarachnoid hemorrhage.
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| 14. |
- Sandvik, Ulrika, 1978-, et al.
(författare)
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Thalamic and subthalamic DBS for essential tremor : where is the optimal target?
- 2012
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Ingår i: Neurosurgery. - Philadelphia : Lippincott, Williams & Wilkins/Congress of Neurological Surgeons. - 0148-396X .- 1524-4040. ; 70:4, s. 840-846
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Tidskriftsartikel (refereegranskat)abstract
- Background: The ventrolateral thalamus (Vim, ventral intermediate nucleus) is the traditional target for neurosurgical treatment of essential tremor (ET). The target has, however, varied substantially among different neurosurgeons.Objective: To evaluate the effect of deep brain stimulation (DBS) in the thalamus and posterior subthalamic area (PSA) in relation to electrode location.Methods: 36 (17Vim / 19 PSA) patients, with 44 DBS electrodes, were included in this retrospective study. The effect of stimulation was evaluated with standardized settings for each contact using items from the essential tremor rating scale (ETRS).Results: When each contact was evaluated regarding the treated hand with standardized stimulation, the electrode contact providing the best effect in the individual patient was in 54% located in the zona incerta (Zi) or radiation prelemniscalis (raprl) and in 12 % the Vim. 40 contacts provided a tremor reduction of >90%. Of these, 43% were located in the PSA and 18% in the Vim according to the Schaltenbrandt atlas. 37 of these 40 contacts were found in the PSA group.Conclusion: More contacts yielding an optimal effect were found in the PSA group than in the Vim. Many patients operated upon in the Vim got the best effect in a contact located in the PSA. This might suggest that the PSA is a more efficient target than the Vim.
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| 15. |
- Sandvik, Ulrika, et al.
(författare)
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Thalamic and subthalamic deep brain stimulation for essential tremor : where is the optimal target?
- 2012
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 70:4, s. 840-845
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The ventrolateral thalamus (ventral intermediate nucleus [ Vim]) is the traditional target for neurosurgical treatment of essential tremor. The target, however, has varied substantially among different neurosurgeons. OBJECTIVE: To evaluate the effect of deep brain stimulation in the thalamus and posterior subthalamic area (PSA) in relation to electrode location. METHODS: Thirty-six (17 Vim/19 PSA) patients with 44 deep brain stimulation electrodes were included in this retrospective study. The effect of stimulation was evaluated with standardized settings for each contact using items from the Essential Tremor Rating Scale. RESULTS: When each contact was evaluated in terms of the treated hand with standardized stimulation, the electrode contact providing the best effect in the individual patient was located in the zona incerta or radiation prelemniscalis in 54% and the Vim in 12%. Forty contacts provided a tremor reduction of > 90%. Of these, 43% were located in the PSA and 18% in the Vim according to the Schaltenbrand atlas. Of these 40 contacts, 37 were found in the PSA group. CONCLUSION: More contacts yielding an optimal effect were found in the PSA group than in the Vim. Many patients operated on in the Vim got the best effect from a contact located in the PSA. This might suggest that the PSA is a more efficient target than the Vim.
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| 16. |
- Smits, Anja, et al.
(författare)
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Seizures and the Natural History of World Health Organization Grade II Gliomas : A Review
- 2011
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 68:5, s. 1326-1333
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Forskningsöversikt (refereegranskat)abstract
- OBJECTIVE:The majority of adults with low-grade gliomas have seizures. Despite the frequency of seizures as initial symptoms and symptoms of later disease, seizures in relation to the natural course of low-grade gliomas have received little attention.METHODS:In this review, we provide an update of the literature on the prognostic impact of preoperative seizures and discuss the tumor-and treatment-related factors affecting seizure control at later stages of the disease.RESULTS:Seizures occur most frequently at disease presentation and predict a more favorable outcome. Initial seizures are correlated with tumor location and possibly indirectly to the molecular profile of the tumor. About 50% of all patients with seizures at presentation continue to have seizures before surgery. Maximal tumor resection, including resection of epileptic foci, is a valuable strategy for improving seizure control. In addition, radiotherapy and chemotherapy, as single therapies or in combination with surgery, have shown beneficial effects in terms of seizure reduction. Recurrent seizures after macroscopically complete tumor resection may be a marker for accelerated tumor growth. Recurrent seizures after an initial transient stabilization after radiotherapy and/or chemotherapy may be a marker for anaplastic tumor transformation.CONCLUSION:Preoperative seizures likely reflect, apart from tumor location, intrinsic tumor properties as well. Change in seizure control in individual patients is frequently associated with altered tumor behavior. Including seizures and seizure control as clinical parameters is recommended in future trials of low-grade gliomas to further establish the prognostic value of these symptoms and to identify the factors affecting seizure control.
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| 17. |
- von Vogelsang, Ann-Christin, et al.
(författare)
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Health-Related Quality of Life 10 Years After Intracranial Aneurysm Rupture : A Retrospective Cohort Study Using EQ-5D
- 2013
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Ingår i: Neurosurgery. - : Lippincott Williams & Wilkins. - 0148-396X .- 1524-4040. ; 72:3, s. 397-405
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Experiencing an aneurysmal subarachnoid hemorrhage (SAH) could affect health-related quality of life (HRQoL) several years after the onset. Long-term studies are scarce, and there is a lack of knowledge of whether HRQoL is affected > 5 years after the onset and, if so, in what dimensions. In the general population, HRQoL decreases with age and with the occurrence of a disease and differs between sexes. Factors that may influence HRQoL after aneurysmal SAH include neurological outcome, perceived recovery, aneurysm treatment, and family support.OBJECTIVE: To measure HRQoL and to explore factors affecting HRQoL 10 years after aneurysmal SAH.METHODS: A consecutive sample of all patients admitted for intracranial aneurysm rupture at a neurosurgical clinic in Stockholm (n = 217, 79.5% of eligible) were followed up from 2007 to 2008, approximately 10 years after aneurysm rupture. HRQoL was measured with EQ-5D, and the results were compared with a general population sample from the Stockholm Public Health Survey 2006 matched by age and sex.RESULTS: Compared with the general population, the aneurysm sample reported significantly more problems in 4 of 5 EQ-5D dimensions—mobility, self-care, usual activities, and anxiety/depression—and had significantly lower EQ-5Dindex and EQ visual analog scale values. Within the aneurysm sample, HRQoL was most affected in respondents with worse Glasgow Outcome Scale values at hospital discharge, respondents with comorbidities, and respondents with low perceived recovery.CONCLUSION: Aneurysmal SAH affects HRQoL to a large extent, even 10 years after the onset, indicating a need for long-term follow-up and support after the onset
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| 18. |
- West, Christian Alexander, et al.
(författare)
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Sensory neuron death after upper limb nerve injury and protective effect of repair : clinical evaluation using volumetric magnetic resonance imaging of dorsal root Ganglia.
- 2013
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 73:4, s. 632-640
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Extensive death of sensory neurons after nerve trauma depletes the number of regenerating neurons, contributing to inadequate cutaneous innervation density and poor sensory recovery. Experimentally proven neuroprotective neoadjuvant drugs require noninvasive in vivo measures of neuron death to permit clinical trials. In animal models of nerve transection, magnetic resonance imaging (MRI) proved a valid tool for quantifying sensory neuron loss within dorsal root ganglia (DRG) by measuring consequent proportional shrinkage of respective ganglia.OBJECTIVE: This system is investigated for clinical application after upper limb nerve injury and microsurgical nerve repair.METHODS: A 3-T clinical magnet was used to image and measure volume (Cavalieri principle) of C7-T1 DRG in uninjured volunteers (controls, n = 14), hand amputees (unrepaired nerve injury, n = 5), and early nerve repair patients (median and ulnar nerves transected, microsurgical nerve repair within 24 hours, n = 4).RESULTS: MRI was well tolerated. Volumetric analysis was feasible in 74% of patients. A mean 14% volume reduction was found in amputees' C7 and C8 DRG (P < .001 vs controls). Volume loss was lower in median and ulnar nerve repair patients (mean 3% volume loss, P < .01 vs amputees), and varied among patients. T1 DRG volume remained unaffected.CONCLUSION: MRI provides noninvasive in vivo assessment of DRG volume as a proxy clinical measure of sensory neuron death. The significant decrease found after unrepaired nerve injury provides indirect clinical evidence of axotomy-induced neuronal death. This loss was less after nerve repair, indicating a neuroprotective benefit of early repair. Volumetric MRI has potential diagnostic applications and is a quantitative tool for clinical trials of neuroprotective therapies.
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| 19. |
- West, Christian Alexander, et al.
(författare)
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Sensory Neurons of the Human Brachial Plexus : A Quantitative Study Employing Optical Fractionation and In-Vivo Volumetric Magnetic Resonance Imaging.
- 2012
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Ingår i: Neurosurgery. - Philadelphia : Lippincott Williams & Wilkins. - 0148-396X .- 1524-4040. ; 70:5, s. 1183-1194
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Extensive neuron death following peripheral nerve trauma is implicated in poor sensory recovery. Translational research for experimentally proven neuroprotective drugs requires knowledge of the numbers and distribution of sensory neurons in the human upper limb, and a novel non-invasive clinical measure of neuron loss. OBJECTIVE: To compare optical fractionation and volumetric MRI of dorsal root ganglia (DRG) in histological quantification and objective clinical assessment of human brachial plexus sensory neurons. METHODS: Bilateral C5-T1 DRG were harvested from 5 human cadavers for stereological volume measurement and sensory neuron counts (optical fractionator). MRI scans were obtained from 14 normal volunteers for volumetric analysis of C5-T1 DRG. RESULTS: 425,409 (SD 15,596) sensory neurons innervate the brachial plexus with a significant difference in neuron counts and DRG volume between segmental levels (p<0.0001), with C7 ganglion containing the most. DRG volume correlated with neuron counts (r=0.75, p<.001). Vertebral artery pulsation hindered C5&6 imaging, yet high resolution MRI of C7, C8 and T1 DRG permitted unbiased volume measurement. In accord with histological analysis, MRI confirmed a significant difference between C7, C8 and T1 DRG volume (p<.001), inter-individual variability (COV 15.3%), and sex differences (p=.04). Slight right-left (R/L) sided disparity in neuron counts (2.5%, p=.04) was possibly related to hand dominance, but no significant volume disparity existed. CONCLUSION: Neuron counts for the human brachial plexus are presented. These correlate with histological DRG volumes and concur with volumetric MRI results in human volunteers. Volumetric MRI of C7-T1 DRG is a legitimate non-invasive proxy measure of sensory neurons for clinical study.
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| 20. |
- Wårdell, Karin, et al.
(författare)
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Relationship Between Laser Doppler Signals and Anatomy During Deep Brain Stimulation Electrode Implantation Toward the Ventral Intermediate Nucleus and Subthalamic Nucleus
- 2013
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Ingår i: Neurosurgery. - : Lippincott Williams & Wilkins. - 0148-396X .- 1524-4040. ; 72:2, s. 127-140
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Deep brain stimulation (DBS) requires precise and safe navigation to the chosen target. Optical measurements allow monitoring of gray-white tissue boundaries (total light intensity [TLI]) and microvascular blood flow during stereotactic procedures.OBJECTIVE: To establish the link between TLI/blood flow and anatomy along trajectories toward the ventral intermediate nucleus (Vim) and subthalamic nucleus (STN).METHODS: Stereotactic laser Doppler measurements were obtained with millimeter precision from the cortex toward the Vim (n = 13) and STN (n = 9). Optical trajectories of TLI and blood flow were created and compared with anatomy by superimposing the Schaltenbrandt-Wahren atlas on the patients' pre- and postoperative images. Measurements were divided into anatomic subgroups and compared statistically.RESULTS: Typical TLI trajectories with well-defined anatomic regions could be identified for the Vim and STN. TLI was significantly lower (P < .001) and microvascular blood flow significantly higher (P = .01) in the Vim targets. Of 1285 sites, 38 showed blood flow peaks, 27 of them along the Vim trajectories. High blood flow was more common close to the sulci and in the vicinity of the caudate/putamen. Along 1 Vim trajectory, a slight bleeding was suspected during insertion of the probe and confirmed with postoperative computed tomography.CONCLUSION: Laser Doppler is useful for intraoperative guidance during DBS implantation because simultaneous measurement of tissue grayness and microvascular blood flow can be done along the trajectory with millimeter precision. Typical but different TLI trajectories were found for the Vim and STN.
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| 21. |
- Zetterling, Maria, et al.
(författare)
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Brain energy metabolism in patients with spontaneous subarachnoid hemorrhage and global cerebral edema
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 66:6, s. 1102-1110
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Previous studies of spontaneous subarachnoid hemorrhage (SAH) have shown that global cerebral edema on the first computed tomography scan is associated with a more severe initial injury and is an independent predictor of poor outcome. Effects of secondary ischemic events also influence outcome after SAH. OBJECTIVE: This study demonstrates that early global edema is related to markers of an increased cerebral energy metabolism as measured with intracerebral microdialysis, which could increase vulnerability to adverse events. METHODS: Fifty-two patients with microdialysis monitoring after spontaneous SAH were stratified according to the occurrence of global cerebral edema on the first computed tomography scan taken a median of 2 hours after the initial bleed. Microdialysis levels of glucose, lactate, and pyruvate were compared between the global edema (n = 31) and no global edema (n = 21) groups. Clinical outcome was assessed with the Glasgow Outcome Scale score at >/= 6 months. RESULTS: Patients with global edema showed significantly elevated lactate and pyruvate levels 70 to 79 hours after SAH and marginally significantly higher levels of lactate 60 to 69 hours and 80 to 89 hours after SAH. There was a trend toward worse outcome in the edema group. CONCLUSION: Patients with global cerebral edema have higher interstitial levels of lactate and pyruvate. The edema group may have developed a cerebral hypermetabolism to meet the increased energy demand in the recovery phase after SAH. This stress would make the brain more vulnerable to secondary insults, increasing the likelihood of energy failure.
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- Bexell, Daniel, et al.
(författare)
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Rat Multipotent Mesenchymal Stromal Cells Lack Long-Distance Tropism to 3 Different Rat Glioma Models
- 2012
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Ingår i: Neurosurgery. - 0148-396X. ; 70:3, s. 731-739
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Viral gene therapy of malignant brain tumors has been restricted by the limited vector distribution within the tumors. Multipotent mesenchymal stromal cells (MSCs) and other precursor cells have shown tropism for gliomas, and these cells are currently being explored as potential vehicles for gene delivery in glioma gene therapy. OBJECTIVE: To investigate MSC migration in detail after intratumoral and extratumoral implantation through syngeneic and orthotopic glioma models. METHODS: Adult rat bone marrow-derived MSCs were transduced to express enhanced green fluorescent protein and implanted either directly into or at a distance from rat gliomas. RESULTS: We found no evidence of long-distance MSC migration through the intact striatum toward syngeneic D74(RG2), N32, and N29 gliomas in the ipsilateral hemisphere or across the corpus callosum to gliomas located in the contralateral hemisphere. After intratumoral injection, MSCs migrated extensively, specifically within N32 gliomas. The MSCs did not proliferate within tumors, suggesting a low risk of malignant transformation of in vivo grafted cell vectors. Using a model for surgical glioma resection, we found that intratumorally grafted MSCs migrate efficiently within glioma remnants after partial surgical resection. CONCLUSION: The findings point to limitations for the use of MSCs as vectors in glioma gene therapy, although intratumoral MSC implantation provides a dense and tumor-specific vector distribution.
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| 26. |
- Mellergård, Pekka, et al.
(författare)
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Differences in Cerebral Extracellular Response of Interleukin-1 beta, Interleukin-6, and Interleukin-10 After Subarachnoid Hemorrhage or Severe Head Trauma in Humans
- 2011
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Ingår i: NEUROSURGERY. - : Williams and Wilkins. - 0148-396X. ; 68:1, s. 12-19
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Microdialysis has become a routine method for biochemical surveillance of patients in neurosurgical intensive care units. OBJECTIVE: To analyze the intracerebral extracellular levels of 3 interleukins (ILs) during the 7 days after major subarachnoid hemorrhage or traumatic brain injury). METHODS: Microdialysate from 145 severely injured neurosurgical intensive care unit patients (88 with subarachnoid hemorrhage, 57 with traumatic brain injury) was collected every 6 hours for 7 days. The concentrations of IL-1 beta and IL-6 were determined by fluorescence multiplex bead technology, and IL-10 was determined by enzyme-linked immunosorbent assay. RESULTS: Presented are the response patterns of 3 ILs during the first week after 2 different types of major brain injury. These patterns are different for each IL and also differ with respect to the kind of pathological impact. For both IL-1 beta and IL-6, the initial peaks (mean values for all patients at day 2 being 26.9 +/- 4.5 and 4399 +/- 848 pg/mL, respectively) were followed by a gradual decline, with IL-6 values remaining 100-fold higher compared with IL-1 beta. Female patients showed a stronger and more sustained response. The response of IL-10 was different, with mean values less than 23 pg/mL and with no significant variation between any of the postimpact days. For all 3 ILs, the responses were stronger in subarachnoid hemorrhage patients. The study also indicates that under normal conditions, IL-1 beta, IL-6, and IL-10 are present only at very low concentrations or not at all in the extracellular space of the human brain. CONCLUSION: This is the first report presenting in some detail the human cerebral response of IL-1 beta, IL-6, and IL-10 after subarachnoid hemorrhage and traumatic brain injury. The 3 ILs have different reaction patterns, with the response of IL-1 beta and IL-6 being related to the type of cerebral damage sustained, whereas the IL-10 response was less varied.
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