Neurosurgery
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The meningeal structure of the cavernous sinus (lateral sellar compartment) was anatomically and histologically studied. We discuss the clinical and surgical significance and present clinical examples of cranial base tumors. ⋯ A surgical technique based on the meningeal anatomy is important for cavernous sinus surgery. The cavernous apex and Meckel's cave, which are spaces of convergence of cranial nerves, however, are weak points for surgical dissection. The presence or absence of tumor invasion into those areas may influence the microsurgical results.
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To determine the indications for, efficacy of, and safety of depth electrode placement using magnetic resonance imaging (MRI)-guided stereotactic surgery in patients with intractable epilepsy. ⋯ We have found intracerebral electrode placement to be as safe as subdural strip electrode placement and have found combined depth and strip electrode monitoring to be highly effective in localizing the onset zones of complex partial seizures. Intracranial monitoring was particularly useful in the detection of a single ictal onset zone in the absence of neuroimaging abnormality and in the definitive diagnosis of bilateral independent ictal onset zones in the temporal lobe epilepsy syndrome. The specific technical aspects of the procedure that contribute to a successful outcome are reviewed. A comparison with earlier reported series suggests that MRI-guided stereotaxy and pial inspection may reduce complications of depth electrode placement.
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The aim of the present study is to monitor the extracellular gamma-aminobutyric acid (GABA) levels in the lumbar dorsal horn of allodynic rats, which respond to spinal cord stimulation (SCS) with a normalization of the tactile withdrawal threshold. In addition, we monitored the GABA levels in nonresponding and sham-stimulated rats. ⋯ Our results indicate that the development of allodynia, a common symptom in neuropathic pain states, may be linked to a decreased spinal release of GABA. We suggest that an SCS-induced release of GABA could be important for the suppression of allodynia observed in rats after SCS. Similar mechanisms could also be involved in the SCS-induced alleviation of pain in patients with peripheral neuropathy.