Journal of neurosurgery
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Journal of neurosurgery · Aug 1999
Convection-enhanced selective excitotoxic ablation of the neurons of the globus pallidus internus for treatment of parkinsonism in nonhuman primates.
Selective treatment of central nervous system (CNS) structures holds therapeutic promise for many neurological disorders, including Parkinson's disease (PD). The ability to inhibit or augment specific neuronal populations within the CNS reliably by using present therapeutic techniques is limited. To overcome this problem, the authors modeled and developed a method in which convection was used to deliver compounds to deep brain nuclei in a reproducible, homogeneous, and targeted manner. To determine the feasibility and clinical efficacy of convective drug delivery for treatment of a neurological disorder, the investigators selectively ablated globus pallidus internus (GPi) neurons with quinolinic acid (QA), an excitotoxin, in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced model of primate parkinsonism. ⋯ Convection-enhanced delivery of QA permits selective, region-specific (GPi), and safe lesioning of neuronal subpopulations, resulting in dramatic improvement in parkinsonian symptomatology. The properties of convection-enhanced delivery indicate that this method could be used for chemical neurosurgery for medically refractory PD and that it may be ideal for cell-specific therapeutic ablation or trophic treatment of other targeted structures associated with CNS disorders.
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Journal of neurosurgery · Jul 1999
Review Case ReportsFusiform vertebral artery aneurysms as a cause of dissecting aneurysms. Report of two autopsy cases and a review of the literature.
Two autopsy cases of angiographically determined fusiform aneurysms of the vertebral arteries (VAs) are reported and the appropriate literature is reviewed to investigate the pathological characteristics of both fusiform and dissecting VA aneurysms and the pathogenesis of dissecting aneurysms. One patient had suffered a subarachnoid hemorrhage (SAH) due to dissection of a previously documented incidental fusiform aneurysm. The other patient had harbored incidental fusiform aneurysms coexistent with a ruptured aneurysm of the posterior inferior cerebellar artery. ⋯ A mural hemorrhage and patchy calcification were also found in the case that included SAH. Based on their pathological investigation of these two cases and a review of reported cases, the authors propose that incidental fusiform aneurysms in the VAs are characterized by weakness in the internal elastic lamina and, therefore, have the potential to become dissecting aneurysms, resulting in a fatal prognosis. This suggests that long-term control of blood pressure is mandatory in patients with incidental fusiform aneurysms in the VAs.
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Journal of neurosurgery · Jul 1999
Case ReportsIncreased inspired oxygen concentration as a factor in improved brain tissue oxygenation and tissue lactate levels after severe human head injury.
Early impairment of cerebral blood flow in patients with severe head injury correlates with poor brain tissue O2 delivery and may be an important cause of ischemic brain damage. The purpose of this study was to measure cerebral tissue PO2, lactate, and glucose in patients after severe head injury to determine the effect of increased tissue O2 achieved by increasing the fraction of inspired oxygen (FiO2). ⋯ Markedly elevated lactate levels in brain tissue are common after severe head injury. Increasing PaO2 to higher levels than necessary to saturate hemoglobin, as performed in the O2-treated cohort, appears to improve the O2 supply in brain tissue. During the early period after severe head injury, increased lactate levels in brain tissue were reduced by increasing FiO2. This may imply a shift to aerobic metabolism.
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Journal of neurosurgery · Jul 1999
Multicenter Study Comparative Study Clinical TrialCurrent use and timing of spinal surgery for management of acute spinal surgery for management of acute spinal cord injury in North America: results of a retrospective multicenter study.
A multicenter retrospective study was performed in 36 North American centers to examine the use and timing of surgery in patients who have sustained acute spinal cord injury (SCI). The study was performed to obtain information required for the planning of a randomized controlled trial in which early and late decompressive surgery are compared. ⋯ These data indicate that although surgery is commonly performed in patients with acute SCI, one third of cases are managed nonoperatively, and there is very little agreement on the optimum timing of surgical treatment. The results of this study confirm the need for a randomized controlled trial to assess the optimum timing of decompressive surgery in SCI.
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Journal of neurosurgery · Jul 1999
Meta Analysis Comparative StudyAn evidence-based review of decompressive surgery in acute spinal cord injury: rationale, indications, and timing based on experimental and clinical studies.
The authors conducted an evidence-based review of the literature to evaluate critically the rationale and indications for and the timing of decompressive surgery for the treatment of acute, nonpenetrating spinal cord injury (SCI). ⋯ There is biological evidence from experimental studies in animals that early decompressive surgery may improve neurological recovery after SCI, although the relevant interventional timing in humans remains unclear. To date, the role of surgical decompression in patients with SCI is only supported by Class III and limited Class II evidence. Accordingly, decompressive surgery for SCI can only be considered a practice option. Furthermore, analysis of the literature does not allow definite conclusions to be drawn regarding appropriate timing of intervention. Hence, there is a need to conduct well-designed experimental and clinical studies of the timing and neurological results of decompressive surgery for the treatment of acute SCI.