肛门和尿道括约肌肌电图对多系统萎缩的诊断价值

Comparative study on diagnostic significance of urethral sphincter versus external anal sphincter electromyography in patients with multiple system atrophy

目的 比较肛门和尿道括约肌肌电图（EAS and US-EMG）对多系统萎缩（MSA）的诊断价值.方法 对2010年6月至2013年1月海军总医院神经科临床确诊的27例MSA患者进行EAS-EMG和US-EMG检查,同时选取同一时期28例非MSA患者为对照进行相应的检查.统计比较两组患者EAS-EMG和US-EMG中轻收缩时运动单位平均时限、平均波幅、多相波百分比,以及大力收缩时的变化.结果 MSA患者轻收缩时限这项指标在两种检查方法中与非MSA患者比较差异均有统计学意义（EAS-EMG,P＜0.001；US-EMG,P=0.002）,而大力收缩募集电位以及多相波百分比只在EAS-EMG检查中两组相比差异有统计学意义（大力收缩募集电位,P=0.016；多相波百分比,P=0.004）；EAS-EMG较US-EMG在反映神经源性损伤的各项指标中变化更明显.结论 US-EMG与EAS-EMG同样对MSA有诊断价值,EAS-EMG各项指标变化在MSA患者中更显著,当EAS-EMG检查受到限制时,US-EMG可起到良好的补充诊断及替代作用.

Objective To evaluate the diagnostic value of external anal sphincter electromyography （EAS-EMG） versus urethral sphincter electromyography （US-EMG） in patients with multiple system atrophy （MSA）.Methods A total of 27 MSA patients were examined with EAS and US-EMG as treatment group while 28 non-MSA subjects as control group.Spontaneous activities during relaxation,mean duration and amplitude of motor unit potential （MUP）,percentage of polyphasicity and variations during strong contraction were recorded and analyzed statistically.Results There was significant difference in light contraction between MSA and non-MSA cases on both EAS-EMG and US-EMG（EAS-EMG,P 〈 0.001 ; USEMG,P =0.002）.Meanwhile,strong contraction and percentage of polyphasicity showed significant differences between MSA and non-MSA cases on EAS-EMG only（strong contraction,P =0.016; percentage of polyphasicity,P =0.004）.EAS-EMG showed more significant changes in neurogenic injury than USEMG.Conclusion US-EMG and EAS-EMG are valuable for the diagnosis of MSA.The differences of multiple parameters of EAS-EMG were more significant than those of US-EMG for MSA cases.US-EMG may serve as a supplement of EAS-EMG in case of restriction.