194 Intraoperative Neurophysiology Clues to Predict Success from Selective Dorsal Rhizotomy for Spastic Diplegic and Hemiplegic Cerebral Palsy

Abstract

INTRODUCTION: Selective dorsal rhizotomy (SDR) involves differential lesioning of divided sensory rootlets at the L1-S1 spinal levels based on interpretations of intraoperative neurophysiologic recordings. It has been shown to improve spasticity related to Cerebral Palsy, but the relationship of specific intraoperative neurophysiology measurements with clinic findings and improvements from surgery has not been investigated. METHODS: We performed a retrospective chart review of 39 consecutive SDRs on pediatric patients with spastic diplegia and hemiplegia, recording preoperative and postoperative toeing, scissoring, crouching, ability to walk, intraoperative stimulation frequencies, the spread of activated muscles, and whether a rootlet was lesioned. Improvement in clinical findings was analyzed as the correlate of surgical success. RESULTS: There was greater improvement in walking ability with more rootlets having a contralateral spread (p = .009), when more of the lesioned rootlets had contralateral spread (p = .005), and when some rootlets with contralateral spread were spared (p = .001). Among patients with preoperative toeing, there was more muscle activation intraoperatively (p < .001), greater improvement in walking ability (p < .001), and greater improvement of toeing when a lower percentage of rootlets were lesioned intraoperatively (p = .033). Among patients with preoperative crouching, there was greater improvement in crouching with smaller differences in stimulation frequency threshold between the motor and sensory roots (p = .041) and when some rootlets with contralateral spread were spared (p = .028). CONCLUSIONS: There is a correlation between preoperative clinical findings, intraoperative neurophysiology measurements, and postoperative clinical findings. These allow for the prediction of intraoperative recordings based on preoperative presentation. We have shown that success from SDR can be predicted using specific intraoperative measurements.