Chang C W
Department of Rehabilitation Medicine, National Taiwan University College of Medicine, Taipei.
Am J Phys Med Rehabil. 1998 Mar-Apr;77(2):118-21.
Neuronal degradation accompanied with axonal degeneration has been known to occur in spinal motor neurons after an upper level of spinal cord lesion. In the present study, the functional integrity of neuromuscular transmission was assessed by utilizing a sensitive electrodiagnostic method comprising of stimulated single-fiber electromyography (SFEMG), along with axonal microstimulation, in paralytic muscles of patients with spinal cord injury (SCI). Neuromuscular jitter was measured in anterior tibial muscles for 30 patients with SCI and also for 12 normal controls. Mean jitter of 37.4 +/- 14.7 (mean +/- SD) micros, as obtained in SCI patients, was found to be significantly greater than the results of 20.1 +/- 8.4 micros in normal controls (P < 0.01). Jitter measurement was not significantly different in varied functional scales of SCI. A positive correlation was noted between the increased jitter and the disease duration from the onset of cord lesion till the time of stimulated SFEMG test (r = 0.68; P < 0.01). The present abnormal finding of neuromuscular jitter provides an electrophysiologic evidence for axonal degeneration and suggests that transsynaptic degeneration of motor neuron may occur below the level of cord lesion in SCI patients. Furthermore, the neuronal degradation in SCI was positively correlated with the course duration of the disease.
已知脊髓上节段损伤后，脊髓运动神经元会发生伴有轴突退变的神经元退变。在本研究中，采用一种敏感的电诊断方法，包括刺激单纤维肌电图（SFEMG）以及轴突微刺激，对脊髓损伤（SCI）患者麻痹肌肉的神经肌肉传递功能完整性进行评估。对30例SCI患者和12名正常对照者的胫前肌进行神经肌肉颤抖测量。结果发现，SCI患者的平均颤抖为37.4±14.7（平均值±标准差）微秒，显著高于正常对照者的20.1±8.4微秒（P<0.01）。在SCI的不同功能量表中，颤抖测量无显著差异。从脊髓损伤发作到刺激SFEMG测试时，颤抖增加与病程呈正相关（r = 0.68；P<0.01）。目前神经肌肉颤抖的异常发现为轴突退变提供了电生理证据，并提示SCI患者在脊髓损伤水平以下可能发生运动神经元的跨突触退变。此外，SCI中的神经元退变与病程呈正相关。
