Beltinger A, Riffel B, Stöhr M
Neurologische Klinik mit klinischer Neurophysiologie, Zentralklinikum, Augsburg, Federal Republic of Germany.
Eur Arch Psychiatry Neurol Sci. 1987;236(6):358-63. doi: 10.1007/BF00377425.
The changes in evoked potentials following median and tibial nerve stimulation in nine patients with clinically defined Friedreich's ataxia are reported and discussed. The response originating in the brachial plexus (Erb's point potential) was absent or reduced in amplitude with no prolongation of peak latency, and the response generated in the cauda equina (N18) was absent in all cases. Conduction time from the brachial plexus to cervical spine and medulla oblongata was normal, whereas the central conduction time (N13a/N20, N13b/N20) was delayed. There was moderate to marked attenuation of the primary cortical response to median nerve stimulation. In one patient N20 disappeared during the course of the disease as opposed to the persisting subsequent negative wave, the latter thus simulating a very marked delay in the primary cortical response. Accordingly the cortical response to tibial nerve stimulation, which was only present in two patients and was markedly delayed, might represent a later potential with the primary response absent. The findings are consistent with neuropathological descriptions of a dying back neuropathy with primary axonal degeneration concerning the 1st order sensory neuron. In addition there is evidence either of delayed conduction in 2nd and 3rd order sensory neurones or of abnormal synaptic transmission.
报告并讨论了9例临床确诊为弗里德赖希共济失调患者在正中神经和胫神经刺激后诱发电位的变化。起源于臂丛神经的反应（厄布点电位）缺失或波幅降低，峰潜伏期无延长，且在所有病例中马尾神经产生的反应（N18）均缺失。从臂丛神经到颈椎和延髓的传导时间正常，而中枢传导时间（N13a/N20、N13b/N20）延迟。对正中神经刺激的初级皮质反应有中度至明显衰减。在1例患者中，疾病过程中N20消失，而随后的负波持续存在，因此后者模拟了初级皮质反应的非常明显延迟。相应地，对胫神经刺激的皮质反应仅在2例患者中出现且明显延迟，可能代表初级反应缺失的较晚电位。这些发现与关于一级感觉神经元原发性轴突变性的逆行性神经病的神经病理学描述一致。此外，有证据表明二级和三级感觉神经元传导延迟或突触传递异常。
