Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
Neurosciences Center, Chinese Academy of Medical Sciences, Beijing 100730, China.
Chin Med J (Engl). 2019 Mar 5;132(5):542-550. doi: 10.1097/CM9.0000000000000117.
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons with no effective cure. Electrophysiological studies have found decremental responses during low-frequency repetitive nerve stimulation (RNS) except for diffused neurogenic activities. However, the difference between ALS and generalized myasthenia gravis (GMG) in terms of waveform features is unclear. In the current study, we explored the variation trend of the amplitudes curve between ALS and GMG with low-frequency, positive RNS, and the possible mechanism is discussed preliminarily.
A total of 85 ALS patients and 41 GMG patients were recruited. All patients were from Peking Union Medical College Hospital (PUMCH) between July 1, 2012 and February 28, 2015. RNS study included ulnar nerve, accessory nerve and facial nerve at 3 Hz and 5 Hz stimulation. The percentage reduction in the amplitude of the fourth or fifth wave from the first wave was calculated and compared with the normal values of our hospital. A 15% decrease in amplitude is defined as a decrease in amplitude.
The decremental response at low-frequency RNS showed the abnormal rate of RNS decline was 54.1% (46/85) in the ALS group, and the results of different nerves were 54.1% (46/85) of the accessory nerve, 8.2% (7/85) of the ulnar nerve and 0% (0/85) of the facial nerve stimulation, respectively. In the GMG group, the abnormal rate of RNS decline was 100% (41/41) at low-frequency RNS of accessory nerves. However, there was a significant difference between the 2 groups in the amplitude after the sixth wave.
Both groups of patients are able to show a decreasing amplitude of low-frequency stimulation RNS, but the recovery trend after the sixth wave has significant variation. It implies the different pathogenesis of NMJ dysfunction of these 2 diseases.
肌萎缩侧索硬化症（ALS）是一种进行性神经退行性疾病，涉及上下运动神经元，目前尚无有效治疗方法。除弥漫性神经源性活动外，低频重复神经刺激（RNS）的电生理研究发现递减反应。然而，ALS 和广义重症肌无力（GMG）在波形特征方面的差异尚不清楚。在本研究中，我们探讨了低频正 RNS 对 ALS 和 GMG 振幅曲线变化趋势的影响，并初步探讨了可能的机制。
共纳入 85 例 ALS 患者和 41 例 GMG 患者。所有患者均于 2012 年 7 月 1 日至 2015 年 2 月 28 日期间来自北京协和医院。RNS 研究包括 3Hz 和 5Hz 刺激的尺神经、副神经和面神经。计算并比较第四或第五波相对于第一波的振幅降低百分比与我院正常值。振幅降低 15%定义为振幅降低。
低频 RNS 递减反应显示 ALS 组 RNS 下降异常率为 54.1%（46/85），不同神经的结果分别为副神经 54.1%（46/85）、尺神经 8.2%（7/85）和面神经刺激 0%（0/85）。GMG 组低频副神经 RNS 的 RNS 下降异常率为 100%（41/41）。然而，两组在第六波后的振幅存在显著差异。
两组患者均能表现出低频刺激 RNS 振幅降低，但第六波后的恢复趋势存在显著差异。这暗示了这两种疾病神经肌肉接头功能障碍的不同发病机制。
