Selective Dorsal Rhizotomy for Spastic Paraplegia in Cerebral Palsy Using Intraoperative Electromyography Monitoring

뇌성마비 환자에서 수술중 근전도 감시를 이용한 선택적 후근 절제술의 효과에 관한 연구

Background & Objectives : In cerebral palsy, spastic paraplegia is one of the most crippling motor manifestations. Reducing the spasticity may improve gait and decrease the incidence of lower-extremity deformities. The spasticity may result from abnormally increased afferent signals via dorsal roots onto interneurons and anterior horn and spreading of reflex activation to other muscle groups. To assess the influence of dorsal rhizotomy to spasticity, the authors analyzed five cerebral palsy patients with spastic paraplegia. Methods : The operation entailed and L1-2 laminectomy, ultrasonographic localization of conus medullaris and identification of lumbosacral dorsal roots. The innervation patterns of each dorsal root were examined by electromyography (EMG) responses to electrical stimulation. Tetanic stimulation was applied to individual rootlets of each root after reflex threshold was determined. the reflex responses were graded and rootlets producing high grade response were selected and cut. Short-term postoperative evaluations were performed. Results : Intraoperative EMG monitoring was satisfactorily performed in all five cases. One month after the operations, all patients showed greatly reduced spasticity which was measured by the instrumental gait analysis. Bilateral knee and ankle jerks were normalized and tip-toe gait with scissoring disappeared in all patients. Conclusion : Intraoperative EMG monitoring seems useful for the selective dorsal rhizotomy to reduce spasticity.