Hirota N, Weber M, Eisen A
The Neuromuscular Diseases Unit, Vancouver Hospital, 855 West 12th Avenue, Vancouver, British Columbia, Canada V5Z 1M9.
J Neurol Sci. 2000 Nov 1;180(1-2):71-5. doi: 10.1016/s0022-510x(00)00417-2.
Peristimulus time histograms (PSTHs) can be used to investigate corticomotoneuronal dysfunction in amyotrophic lateral sclerosis (ALS). The most characteristic change is temporal dispersion of the primary peak. We recorded PSTHs in the extensor digitorum communis with voluntary motor units activation (standard PSTHs) or at rest (non-activated PSTHs). Standard PSTHs were recorded in 29 motor units of 12 healthy control subjects and 12 sporadic ALS patients. Double primary peaks were seen in three motor units of two healthy control subjects and 10 motor units from five ALS patients. The number of subpeaks was up to three in most of the normal motor units as well as in the earlier component of double primary peaks. The subpeaks were smaller and less discernible in the later component of double primary peaks. Non-activated PSTHs of ALS patients demonstrated similar decomposition of subpeaks in the motor units with significantly increased variability of latency. Similar findings in the standard PSTHs and non-activated PSTHs suggest that the abnormalities seen in ALS are independent of the membrane potential of the spinal motoneuron and therefore supraspinal in origin. The decomposed additional later component may indicate activation of slow conducting corticospinal tracts.
刺激时间直方图（PSTHs）可用于研究肌萎缩侧索硬化症（ALS）中的皮质脊髓运动神经元功能障碍。最具特征性的变化是主峰的时间离散。我们在指总伸肌中记录了PSTHs，记录时或为随意运动单位激活状态（标准PSTHs），或为静息状态（未激活PSTHs）。在12名健康对照者和12例散发性ALS患者的29个运动单位中记录了标准PSTHs。在2名健康对照者的3个运动单位和5例ALS患者的10个运动单位中观察到双主峰。在大多数正常运动单位以及双主峰的较早成分中，子峰数量多达三个。在双主峰的较晚成分中，子峰较小且较难分辨。ALS患者的未激活PSTHs显示，运动单位中的子峰有类似的分解情况，潜伏期变异性显著增加。标准PSTHs和未激活PSTHs中的类似发现表明，ALS中所见的异常与脊髓运动神经元的膜电位无关，因此起源于脊髓以上部位。分解出的额外较晚成分可能表明慢传导皮质脊髓束被激活。
