帕金森病及多系统萎缩运动皮质兴奋性的比较

Motor cortex excitability in Parkinson＇s disease and multiple system atrophy

目的观察帕金森病（PD）及多系统萎缩（MSA）患者运动皮质兴奋性的差异，并探讨磁刺激双上肢运动诱发电位（MEP）能否作为鉴别二者的神经电生理指标之一。方法选取2005至2010年我院的PD患者34例作为PD组，MSA患者22例作为MSA组，年龄性别相匹配的正常健康者15例作为正常对照组。采用磁刺激双上肢MEP作为观察指标，比较3组静息阈值（RMT）、中枢传导时间（CMCT）、波幅（AMP）的变化及与病情严重程度的关系。结果PD组患者RMT较MSA组及正常对照组明显降低，差异具有统计学意义（P〈0．01），MSA组RMT较正常对照组降低，差异有统计学意义（P〈0．01）；3组中枢传导时间（CMCT）差异无统计学意义（P〉0．05）；PD组患者AMP明显高于MSA组和正常对照组，差异有统计学意义（P〈0．01），MSA组AMP与正常对照组比较，差异无统计学意义（P〉0．05）。随PD患者病情加重，皮质RMT进行性降低，CMCT进行性缩短，AMP无明显变化；而MSA患者RMT、CMCT、AMP与病情严重程度无关。结论PD与MSA患者运动皮质兴奋性存在差异，双上肢运动诱发电位RMT和CMCT在鉴别PD和MSA上有一定参考价值．波幅改变的临床意义尚待进一步研究。

Objective To observe any differences in motor cortex excitability between Parkinson＇s disease （PD） patients and patients with multiple system atrophy （MSA） and to explore whether motor evoked potentials （MEPs） can be used as an electrophysiological indicator for differentiating the 2 diseases. Methods Thirty-four PD patients, 22 MSA patients and 15 age- and sex-matched healthy control subjects were included in this study. Relaxed motor thresholds （RMTs）, central motor conduction time （CMCTs） and MEP amplitudes （AMPs） were recorded in all three groups. The relationships of RMT, CMCT and AMP with the severity of the disease were observed. Results Average RMT in the PD group was significantly lower than that in the MSA and control groups. Average RMT in the MSA group was also signifi- cantly lower than that in the control group. There was no significant difference among the three groups with regard to CMCT. AMP in the PD group was significantly higher on average than in the MSA and control groups, but there was no significant difference between the MSA and control groups. RMT decreased and CMCT shortened progressively with the severity of the disease in the PD group, but not in the MSA group. Conclusions There were differences in motor cor- tex excitability between PD patients and MSA patients. MEP RMTs and CMCTs may be valuable for identifying PD and MSAc but the clinical significance of the amplitude differences remains to be further explored.