Mima T, Terada K, Ikeda A, Fukuyama H, Takigawa T, Kimura J, Shibasaki H
Department of Brain Pathophysiology, Kyoto University School of Medicine, Japan.
Electroencephalogr Clin Neurophysiol. 1997 Jan;104(1):51-9. doi: 10.1016/s0168-5597(96)96089-x.
Proprioception-related somatosensory evoked potentials (SEPs) to passive flexion movement of the middle finger at proximal interphalangeal joint were recorded in 7 patients with myoclonus of cortical origin who demonstrated enlarged electrical SEPs (giant SEPs). In 3 out of the 7 patients, the proprioception-related SEPs were also enlarged. The remaining 4 patients showed giant electrical SEPs without enhancement of proprioception-related SEPs. Long loop electromyographic response was recorded during the resting condition in all of the 3 patients with enlarged proprioception-related SEPs. We have previously reported that proprioception-related SEPs are mainly generated by muscle afferent inputs, though electrical SEPs are thought to reflect mostly cutaneous inputs with some contribution from muscle afferents. Therefore, it is concluded that hyperexcitability of the sensorimotor cortex in cortical myoclonus is modality-specific. Cortical excitability is exaggerated to both cutaneous and deep receptor inputs in some patients, but only to cutaneous input in others.
对7例皮质起源的肌阵挛患者进行记录，这些患者表现出体感诱发电位（SEP）增大（巨大SEP），记录的是在近端指间关节被动屈曲中指时与本体感觉相关的体感诱发电位。7例患者中有3例与本体感觉相关的SEP也增大。其余4例患者表现出巨大的电SEP，但与本体感觉相关的SEP未增强。在所有3例与本体感觉相关的SEP增大的患者静息状态下记录了长环肌电图反应。我们之前曾报道，与本体感觉相关的SEP主要由肌肉传入输入产生，而电SEP被认为主要反映皮肤输入，肌肉传入有一定贡献。因此，得出结论，皮质肌阵挛中感觉运动皮质的过度兴奋性是模式特异性的。在一些患者中，皮质兴奋性对皮肤和深部感受器输入均有夸大，但在另一些患者中仅对皮肤输入有夸大。
