肌萎缩侧索硬化患者膈神经传导的临床应用及特点

目的　探讨膈神经传导在肌萎缩侧索硬化 (ALS)患者中的临床应用及特点。方法　以表面电极在肋间隙处记录电刺激 4 4例ALS患者及 31例正常对照者颈部膈神经时产生的膈肌复合肌肉动作电位之潜伏期和波幅。 2 8例ALS患者同时接受了用力肺活量百分比 (%FVC)测定。结果　ALS患者右、左侧膈神经远端运动潜伏期 (PDML)分别为 8 4ms± 2 2ms和 7 6ms± 1 4ms ,均较对照者延长 ,波幅对数为 2 6 8± 0 37,比对照者低 ;以右侧为例 ,PDML与 %FVC相关 ,但与临床呼吸困难无关 ;波幅与 %FVC和临床呼吸困难均无关。PDML阳性率 (47 7% )高于临床呼吸困难出现率(2 5 0 % )。结论　PDML是膈神经传导参数中反映ALS患者呼吸功能障碍的敏感指标 ,但只有将其与膈肌运动诱发电位的中枢运动传导时间结合 ,方能更全面揭示呼吸受累的本质

Phrenic nerve conduction in amyotrophic lateral sclerosis patients

OBJECTIVE: To investigate the features and application of phrenic nerve conduction in amyotrophic lateral scle-rosis (ALS) patients. METHODS: The latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) were recorded among 44 ALS patients and 31 control subjects with surface electrodes after the cervical part of phrenic nerve was stimulated with electricity. The percentage of forced vital capacity (%FVC) was examined in 28 ALS patients simultaneously. RESULTS: Right and left phrenic distal motor latencies (PDML) of ALS patients were 8.4 ms +/- 2.2 ms and 7.6 ms +/- 1.4 ms respectively, longer than those of the controls, and the logarithmic value of amplitudes among ALS patients was 2.68 +/- 0.37, lower than that among the controls. Take the right side for example, although PDML was correlated with %FVC, it had no correlation with clinical respiratory dysfunction. Neither %FVC nor clinical respiratory dysfunction was correlated with the amplitude of DCMAP. The rate of abnormal PDML (47.7%) was higher than the rate of clinical dyspnea (25%). CONCLUSION: PDML is a sensitive index in phrenic conduction parameter reflecting respiratory dysfunction in ALS. Only when the PDML is combined with the central motor conduction time of the diaphragmatic motor evoked potential the nervous system basis of the respiratory disturbance in ALS can be revealed.