Single-stimulus-induced EMG stability during SDR in children with spastic cerebral palsy

CHENG Qing; HE Yuyan; ZHAO Qingshuang; ZHANG Taotao; JING Junjie; XIAO Bo

doi:10.3639/j.issn.1671-2897.2025.04.012

Abstract：Objective To clarify the reliability of the single stimulus Trigger-electromyography(EMG)protocol.Methods A retrospective analysis was made of the clinical and intra-operative neurophysiological monitoring data of children with spastic cerebral palsy undergoing selective dorsal rhizotomy(SDR)surgery at Fujian Children's Hospital from July 2023 to June 2024.The directional muscle group that first reached a wave amplitude of 200 mV after two consecutive electrical stimulations of the posterior roots of sensory nerves related to lower limbs during SDR surgery,as well as the top three muscle groups with the maximum evoked muscle wave amplitude after two stimulations were compared,and the stability(directionality and spreading)of a single stimulation Trigger-EMG protocol was analyzed.Results A total of 131 nerve roots were stimulated during surgery in the 20 patients,including 89(67.9%)nerve roots related to lower limb sensation and 42(32.1%)nerve roots related to sphincter function.Among the 89 sensory nerves related to both lower limbs induced by single stimulation Trigger-EMG,the current intensity of the two consecutive electrical stimulations was(1.46±1.11)mA and(1.47±1.11)mA respectively.The amplitude of electromyographic waves induced by targeted muscle groups were(286.04±80.15)μV and(257.09±56.71)μV respectively.There was no significant statistical difference,as 91.0%(81/89)of the directed muscle groups that reached a wave amplitude of 200 μV during the two consecutive stimuli were completely consistent.The rates of consistent and almost consistent induction of electromyographic expansion were 91.0%(81/89)and 6.7%(6/89)respectively.Conclusion Under stable stimulation intensity,single stimulation of the posterior root of the spinal nerve Trigger-EMG has good stability and repeatability in targeting and expanding muscle groups.The use of single stimulation Trigger-EMG in SDR surgery is reliable.