目的探讨运动单位动作电位的平均发放间隔(IPI)在痉挛型脑瘫儿童评估中可行性。方法选取符合标准的64例9~160个月痉挛型脑瘫患儿作为实验组,64例正常儿童作为对照组。利用表面肌电技术结合力学加速度计,基于经验模态分解(EMD)的三级滤波器技术和平滑非线性能量算子(SNEO)算法,算出脑瘫患儿和正常儿童运动单位动作电位(MUAP)的平均IPI并进行对照分析;采用中文版粗大运动功能88项测试(GMFM88项)和分级系统(GMFCS)、临床痉挛指数(CSI)等量表对脑瘫患儿进行粗大运动功能和痉挛程度的评定,将量表评估结果同对应的IPI进行统计学相关回归分析。结果实验组表面肌电MUAP的平均IPI明显高于对照组(P〈0.05);肌电信号的IPI与GMFCS分级、痉挛亚型、痉挛指数及痉挛程度呈正相关(L分别为0.903、0.527、0.663、0.499,P〈0.01);与GMFM88项总评分呈负相关(rs=-0.744,P〈0.01);与月龄及性别无明显相关性。逐步回归方程为多=6.019+1.011x,-0.66x,(y、x1、z2分别代表IPI、CSI、GMFM88项总评分),R2=0.642。结论基于EMD的三级滤波器技术和SNEO算法,计算出的表面肌电信号MUAP的IPI与脑瘫儿童的痉挛状态、运动功能密切相关,可作为痉挛型脑瘫患儿的客观性、综合性的量化评估指标。
Objective To investigate the evaluation value of inter-pulse interval of Motor Unit Action Potential in children with spastic cerebral palsy. Methods Clinical data of 64 children in the age range from 9 to 160 months with spastic cerebral palsy were collected as the experimental group, and 64 normal children were selected as the control group. Surface electromyogram (sEMG) signal was collected from their legs. The inter-pulse interval (IPI) of MUAP was calculated through Smoothed Nonlinear Energy Operator algorithm, then the two sets of data were matched through comparative analysis. Simultaneously, motor function and spasticity of these children were assessed by Chinese version of the Gross Motor Function Measurement-88 (GMFM88) , Chinese version of the Gross Motor Function Classification System (GMFCS) and clinical spasticity index (CSI). Statistical correlation and regression analysis were applied to examine the multivariate association between the five explanatory variables (gender, age, GMFM88 total scores, GMFCS classification results and spasticity) and their corresponding IPI. Results The difference between the IPI of experimental group and the control group was significant ( P 〈 0. 05 ). The correlation of IPI with GMFCS classification, spasm subtypes and spasticity index and spasticity showed positive (r, was 0. 903, 0. 527, 0. 663,0. 499 in respectively, P 〈0. 01 ), but correlation between the IPI and GMFM88 total score was negative ( r, = - 0. 744, P 〈 0. 01 ). At the same time, correlation with age and sex was not significant; Regression equation u =6. 019 + 1. 011x1 -0.66x2 (y = IPI, x1 = CSI,x2 = GMFM88 total scores), R2 =0. 642. Conclusion The IPI of MUAP has significant correlations with the spasticity and motor function in children with spastic cerebral palsy, which can be used as a comprehensive and quantitative assessment index for children with spastic cerebral palsy