Application of endoscopic selective posterior rhizotomy in the treatment of limb spasticity following brain injury

Abstract

Objective To evaluate the efficacy and safety of endoscopic selective posterior/dorsal rhizotomy (SPR) in the treatment of limb spasticity following brain injury in adults. Methods A total of 88 patients with limb spasticity following brain injury treated with SPR from January 2015 to August 2016 at Department of Neurosurgery, Xinxiang Central Hospital were retrospectively enrolled into this study. Russman-Gage standard and Ashworth standard were used to evaluate the degree of limb spasticity and muscle tension after operation. Surface electromyography (SMG) and evoked potential (EP) were used to measure the sensory and motor nerve conduction velocities of affected limbs 3 weeks after operation. Lower extremity motor function was assessed with the Fugl-Meyer scale in lower extremity (FMA-L) at 3 and 8 weeks after operation. Walking ability was assessed with the Functional ambulation category (FAC) scale, and parameters of patients' stride, stride distance, stride speed and toe deflection angle distance were measured. All patients were followed up clinically after operation. The follow-up included observing the remission of limb spasticity and reviewing the lumbar spine radiographs. Results The spasticity of extremities was alleviated in 88 patients after operation. Three weeks after operation, the integrated electromyogram (iEMG) of tibialis anterior muscle in 88 patients was higher than that before operation (1.5±0.2 mV vs. 0.5±0.2 mV, P<0.001), while the gastrocnemius muscle was lower than that before operation (0.7±0.3 mV vs. 1.2±0.2 mV, P<0.001). After detection, latency of cortical somatosensory evoked potential (SEEP) in the dorsomedian part of the head(39.7±3.1 ms) and L2 (18.5±3.5 ms) was longer than that before operation (34.9 ±3.5 ms, 13.3 ±2.3 ms, both P<0.001). The sensory nerve conduction velocities in head (4.9±1.1 cm/ms) and popliteal region to L2(4.8±1.3 cm/ms) region were lower than those before operation (6.6±1.4 cm/ms, 6.3±1.5 cm/ms, both P<0.001). At 3-8 weeks post operation, the scores of FMA-L and FAC scales, stride length, stride distance and stride speed of 88 patients were higher than those before operation (all P<0.05), while the deflection angle of toes was lower (P<0.01). The rising trend time of 88 patients ranged from 6.2 to 26.6 months, with an average of 12.2±6.4 months. There were 83 (83/88, 94.3%) patients who had relief of spasticity in lower limbs and 74 (74/79, 93.7%) whose Achilles tendon reflex disappeared. No spinal deformity was found in the reexamination. Conclusion The neuroendoscopic SPR treatment for limb spasticity after brain injury could effectively relieve the symptoms of limb spasticity and promote the recovery of motor function. It seems safe and worthy of clinical application and promotion. Key words: Natural orifice endoscopic surgery; Craniocerebral trauma; Muscle spasticity; Extremities; selective posterior/dorsal rhizotomy