Stereotactic and functional neurosurgery
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Stereotact Funct Neurosurg · Jan 1993
Clinical TrialExperience with 509 plate electrodes implanted epidurally from C1 to L1.
This article summarizes the experience gained with implantation of 509 plate electrodes performed by a single neurosurgeon. 350 patients were subjected to implantation of plate electrodes in the dorsal epidural space. 227 patients were implanted for chronic pain management (reflex sympathetic dystrophy, failed back syndrome/arachnoiditis, pain following spinal cord injury, nerve injury pain and other miscellaneous pain conditions), 105 patients for motor disorders (spasms/spasticity following spinal cord or head injury, cerebral palsy, multiple sclerosis, spasmodic torticollis and other miscellaneous conditions) and 18 patients for both. A total of 509 electrodes were implanted in the dorsal epidural space. ⋯ Electrode migration occurred in 1.1% of the patients and electrode breakage in 4 patients. 288 (70%) of the implanted electrodes are still being used. Technical factors relevant to the surgical implantation of plate electrodes at various levels in the spine are presented and discussed.
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Stereotact Funct Neurosurg · Jan 1993
Comparative StudyRelease of neurotransmitters in the CNS by spinal cord stimulation: survey of present state of knowledge and recent experimental studies.
Electric stimulation applied to the posterior surface of the spinal cord (SCS) is an established treatment in certain chronic pain syndromes resistant to conventional therapeutic procedures. Despite the clinical value of SCS, the mechanisms behind the efficacy of the method are largely unknown. Several neurotransmitters in the CNS (e.g. opioids, serotonin, noradrenaline, substance P, GABA), have been proposed to be involved in the pain-alleviating effect of SCS. ⋯ In the rats with PAG microdialysis, the GABA level decreased significantly following two stimulation periods, although transitional increases during SCS were noted in some animals. In the decerebrated cat, a significant release of serotonin in the dorsal horn was obtained with SCS, while the levels of the metabolite 5-HIAA were little influenced by stimulation. On the contrary, in the decerebrated preparation there was no release of substance P in the dorsal horn with SCS, although in the intact cat under barbiturate anesthesia a significant release was induced.4+ off
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Stereotact Funct Neurosurg · Jan 1993
Comparative StudyAnalysis of parameters for epidural spinal cord stimulation. 3. Topographical distribution of paresthesiae--a preliminary analysis of 266 combinations with contacts implanted in the midcervical and midthoracic vertebral levels.
As a part of the systematic analysis of parameters involved in electrical epidural spinal cord stimulation therapy, distribution of paresthesiae in accordance with the position of contacts, as related to midline and vertebral level of contacts, was investigated. A preliminary analysis performed for 266 combinations having contacts implanted in the midcervical and low-thoracic vertebral levels showed that the topographical spread of the paresthesiae did not always cover the classical dermatomes. ⋯ This preliminary analysis suggests that more detailed studies would be worthwhile in the investigation of sensory responses to electrical stimulation of the spinal cord with epidural electrodes. Findings from such investigations could also be useful to extend our present anatomical knowledge of central and peripheral sensory neural structures.
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Temporary implants of high-activity 125iodine sources have been used in the treatment of brain tumors since December 1979 at the University of California, San Francisco. For previously untreated patients who underwent external beam radiation therapy followed by implant boost, median survival from the date of diagnosis was 88 weeks for 34 patients with glioblastoma multiforme (GM) and 157 weeks for 29 patients with nonglioblastoma gliomas (NGM). ⋯ Finally, in 48 patients with recurrent tumors treated with combined hyperthermia and brachytherapy, median survival from the date of the implant was 46 weeks for 25 patients with GM and 44 weeks for 7 patients with metastases; 18-month survival was 65% for 16 patients with NGM. Brachytherapy appears to be a useful technique for the treatment of selected recurrent brain tumors and selected primary glioblastomas.
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Stereotact Funct Neurosurg · Jan 1992
Comparative StudyDorsal root entry zone stimulation for deafferentation pain.
Dorsal root entry zone (DREZ) stimulation was performed in 12 patients with chronic pain syndromes after extensive trials of medical therapy, sympathectomy or peripheral nerve stimulation had failed, with 50% of them obtaining excellent long-term benefit. Evoked potential monitoring to facilitate positioning of electrodes under either general or spinal anesthesia, and postoperatively to explore the mechanism of action, revealed findings distinct from those reported with conventional spinal cord stimulation (SCS). DREZ stimulation may function on a different neurophysiologic basis than conventional SCS, involving intersegmental processing and influencing tract of Lissauer functions or the dorsal horn directly.