| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
Multiple subpial transection (MST) is used as a surgical treatment for patients with intractable seizures whose epileptogenic lesions lie in the unresectable cortex. This was a procedure proposed on the basis of anatomic and physiological data, which suggested that gerional seizure propagation depends on horizontal connections in the cerebral cortex, whereas normal cortical functionns are related to the vertical domain. MST was developed to interrupt the spread of epileptogenic discharges selectively while preserving cortical functions, and its clinical use was first described by Morrell in 1989. However, this procedure has not been accepted universally by neurosurgeons. The aim of this study was to evaluate the electrophysiological effect of MST on interneural discharge spread in an epilepsy model, i.e.acute cortical kindling in rabbits, and evaluate its clinical effect in patients with intractable seizures.
Experimental MST in the cortices of adult rabbits was performed, and 7 days later, the parietal cortex posterior to the transected zone was subjected to repeated electrical stimulation. The differerence between the after-discharge (AD) durations at the frontal (opposite the transected zone) and parietal cortices of the MST group was significantly greater than the control group value (n=7, p<0.01). This result suggests that MST interrupts excitatory interneuronal conduction of epileptogenic discharges. In our clinical study, 6 patients underwent MST.Two became seizure-free and the seizure frequencies of the other 4 patients were reduced by 70 - 90%. Our experimental study confirmed MST was effective, but it did not always completely interrupt the spread of epileptogenic discharges, clinically. This discrepancy may be explained by the anatomical fact that 54.9 (]SY.+-。[) 7.2% of the human cortex is buried in sulci where the procedure is technically difficult to perform.
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