尺神经复合肌肉动作电位改变在吉兰-巴雷综合征和慢性炎性脱髓鞘性周围神经病中的特点

Segmental and Short-segmental Changes of CMAP Along Ulnar Nerve in Guillain-Barré Syndrome and Chronic Inflammatory Demyelinating Perineuropathy

目的:探讨节段和短段刺激尺神经后不同节段复合肌肉动作电位(CMAP)负波各参数变化及传导阻滞在吉兰-巴雷综合征(GBS)和慢性炎性脱髓鞘性周围神经病(CIDP)中的意义。方法:20例GBS和12例CIDP患者行尺神经5点分段刺激(腕、肘下、肘上、腋和Erb's点)和短段刺激,记录CMAP负波波幅、时程和面积的变化,分析各参数与临床肌力的相关性。结果:在GBS中,尺神经CMAP负波的时程、波幅和面积的变化在Erb's点到腕部的各节段中差异很大;波幅与面积的衰减与临床肌力呈高度相关(r=-0.905和-0.907);传导阻滞多见于近端和肘部,时程离散不明显。在CIDP中,各节段中的参数变化差异不大;远端波幅与临床肌力相关(r=0.586);传导阻滞在各节段均可出现,常伴明显的时程延长。结论:GBS和CIDP中尺神经CMAP负波的波幅、面积和时程3个参数,可从电生理角度帮助我们认识脱髓鞘疾病的特点。

To evaluate the characteristics of amplitude, area and duration of compound muscle action potential （CMAP） as well as conduction block in different ulnar segments in Guillain-Barré syndrome（GBS） and chronic inflammatory demyelinating perineuropathy（CIDP） by segmental and short-segmental stimulation. Methods： Changes of amplitude, area and duration of ulnar CMAP at 5 different stimulation sites （wrist, below elbow, above elbow, axilla and Erb＇s point） were analyzed from 20 GBS and 12 CIDP patients. Short-segment stimulation was used if conduction block was found. The relationship between electrophysiological parameters and weakness and the presence and characteristics of conduction block（CB）were also studied. Results： In GBS, changes of amplitude, area and duration differed significantly among segments from Erb＇s point to wrist. The close relationship was revealed between both amplitude and area decay and muscle strength （r=-0.905 and -0.907 respectively）. CBs were more frequent at proximal segments or at elbow with focal CB but without obvious duration increase. In CIDP, differences were less obvious among ulnar segments. Correlation was found only between distal CMAP amplitude and muscle strength（r=-0.586）. CBs were characterized by generalized in distribution with rare focal CB and frequent duration increase. Conclusion： Electrophysiologically, changes of amplitude, area and duration of ulnar CMAP were different in GBS and CIDP. Analysis of the three parameters of CMAP negative peak can provide us with clearer electrophysiological understanding of demyelinating neuropathy.