Journal of neurosurgery
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Journal of neurosurgery · Jul 2000
Comparative StudyMicroendoscopic posterior cervical foraminotomy: a cadaveric model and clinical application for cervical radiculopathy.
Cervical radiculopathy caused by either soft herniated disc material or foraminal stenosis is a common problem. Anterior and posterior surgical approaches are commonly used to decompress the nerve root. The authors undertook a study to establish the feasibility of performing a microendoscopic posterior approach for cervical foraminotomy in the clinical setting. ⋯ The advantages to this technique include improved intraoperative visualization, a smaller incision, and significantly less postoperative discomfort compared with a traditional keyhole approach.
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Journal of neurosurgery · Jul 2000
Acute cervical cord injury without fracture or dislocation of the spinal column.
It is known that the spinal cord can sustain traumatic injury without associated injury of the spinal column in some conditions, such as a flexible spinal column or preexisting narrowed spinal canal. The purpose of this study was to characterize the clinical features and to understand the mechanisms in cases of acute cervical cord injury in which fracture or dislocation of the cervical spine has not occurred. ⋯ Degenerative changes of the cervical spine and developmental narrowing of the spinal canal are important preexisting factors. In the acute stage MR imaging is useful to understand the level and mechanisms of spinal cord injury. The fact that a significant number of the patients were found to have spinal cord compression despite the absence of bone injuries of the spinal column indicates that future investigations into surgical treatment of this type of injury are necessary.
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Clinical microdialysis enables monitoring of the cerebral extracellular chemistry of neurosurgical patients. Introduction of the technique into different hospitals' neurosurgical units has resulted in variations in the method of application. There are several variables to be considered, including length of the catheter membrane, type of perfusion fluid, flow rate of perfusion fluid, and on-line compared with delayed analysis of samples. The objects of this study were as follows: 1) to determine the effects of varying catheter characteristics on substance concentration; 2) to determine the relative recovery and true extracellular concentration by varying the flow rate and extrapolating to zero flow; and 3) to compare substance concentration obtained using a bedside enzyme analyzer with that of off-line high-performance liquid chromatography (HPLC). ⋯ Two adjacent microdialysis catheters that were identical in membrane length, perfusion fluid, and flow rate showed equivalent results. Variations in perfusion fluid and freezing and thawing of samples did not result in differences in substance concentration. Catheter length had a significant impact on substance recovery. Variations in flow rate enabled the relative recovery to be calculated using a modification of the extrapolation-to-zero-flow method. The recovery was approximately 70% at 0.3 microl/minute and 30% at 1 microl/minute (10-mm membrane) for all analytes. Glutamate results obtained with the enzyme analyzer showed good correlation with those from HPLC.
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Journal of neurosurgery · Jul 2000
Surgical evaluation and management of lumbar synovial cysts: the Mayo Clinic experience.
The authors report a retrospective analysis of 194 patients surgically treated at their institutions for symptomatic lumbar synovial cysts from January 1974 to January 1996. ⋯ Lumbar synovial cysts are a more common cause of lumbar radicular pain than previously thought. Surgical removal of the cyst is a safe and effective treatment for symptomatic relief in patients with lumbar synovial cysts. A concomitant fusion procedure may be performed in select cases. In this study, only a few patients developed symptomatic spinal instability requiring a second operation.
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Journal of neurosurgery · Jul 2000
Case ReportsSpinal intramedullary cavernoma: clinical presentation and surgical outcome.
Improved neuroimaging techniques have led to an increase in the reported cases of intramedullary cavernomas. The purpose of this study was to define the spectrum of presenting signs and symptoms in patients with spinal intramedullary cavernomas and to analyze the role of surgery as a treatment for these lesions. ⋯ Magnetic resonance imaging is virtually diagnostic for spinal cavernoma lesions. Patients with spinal intramedullary cavernomas presented with either an acute onset of neurological compromise or a slowly progressive neurological decline. Acute neurological decline occurs secondary to hemorrhage within the spinal cord. Chronic progressive myelopathy occurs due to microhemorrhages and the resulting gliotic reaction to hemorrhagic products. There is no evidence that cavernomas increase in size. The rate of rebleeding is unknown, but spinal cavernomas appear to be clinically more aggressive than cranial cavernomas, probably because the spinal cord is less tolerant of mass lesions. Complete surgical removal of the cavernoma was possible in 15 of 16 of the authors' cases.