Stereotactic and functional neurosurgery
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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.
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Stereotact Funct Neurosurg · Jan 1992
Case ReportsRelief from chronic pelvic pain through surgical lesions of the conus medullaris dorsal root entry zone.
Dorsal root entry zone (DREZ) lesions are effective in treating specific pain syndromes, most notably post-brachial plexus avulsion. There is limited experience, however, with lesions in the conus medullaris. ⋯ Her pain was completely relieved after DREZ lesions were placed bilaterally at S2, S3, S4 and S5. The intraoperative sensory and motor evoked potential monitoring used to define the level is described in detail.
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Stereotact Funct Neurosurg · Jan 1992
Surgery of central sensory motor and dorsolateral frontal lobe seizures.
Ten patients who presented with dorsolateral or frontocentral seizures were studied with chronic subdural grid electrodes. Cortical mapping, sensory-evoked potentials and chronic electrocorticography were obtained for each patient. Seizures were classified as focal, regional or dipolar. ⋯ Two patients are seizure-free and 7 patients had a significant reduction in seizure frequency. One patient had no change in seizure pattern. Dorsolateral frontal lobe seizures have a focal functional anatomy and can be surgically treated by selective cortectomy.
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Stereotact Funct Neurosurg · Jan 1992
Clinical and technical results from spinal stimulation for chronic pain of diverse pathophysiologies.
Spinal stimulation has been indicated for pain of peripheral deafferentation, but not for low-back pain. Technical and clinical records of 241 consecutive spinal stimulator recipients were reviewed, including: peripheral deafferentation pain (n = 44); predominant pain of low back, postlaminectomy (n = 96), and predominant pain of leg(s), postlaminectomy (n = 48). ⋯ For the postlaminectomy syndromes, only the technical results correlated significantly with outcome. Spinal stimulation actually yielded results as good for the 'failed back surgery syndrome' as for peripheral deafferentation pain, because newer technical methods were proven to stimulate the low back predictably.
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Stereotact Funct Neurosurg · Jan 1992
In vivo and in vitro study of the lesions produced with a computerized radiofrequency system.
For many years, radiofrequency-generated lesions have been used for the treatment of pain and abnormal movements. However, the reliability of this method has been questioned because of the variation in the size of lesions produced by the electrode at different times and temperatures. A 500-kHz radiofrequency generator with different electrodes was used to determine the size of lesions, using different time and temperature exposures. ⋯ In contrast, the use of different times at the same level of temperature showed no significant increase in most of the electrodes. There were two statistical significant time effects, for both diameter and length, with the monopolar 2-mm electrode. The use of real-time monitoring with graphic display and the feedback information provided for the computerized control of power and current allows high precision of the temperature at the electrode tip during the production of the lesion.