痉挛性斜颈体感诱发电位的研究

目的：探讨痉挛性斜颈患者大脑皮层功能的变化。方法：对30例痉挛性斜颈患者刺激正中神经后体感诱发电位（SEP）的P22、N30波潜伏期及P22、N30波幅进行比较分析，30例正常对照组仅在颈部主动向右侧扭转时对双侧P22、N30波幅进行比较分析。结果：病例组SEPP22、N30潜伏期正常，双侧比较差异无统计学意义，头部扭转方向的对侧大脑半球前中央区的P22-N30波幅比明显高于对侧，差异有统计学意义。正常对照组前中央区记录的双侧P22N30波幅比较差异无统计学意义。结论：SEP P22、N30潜伏期正常提示传导通路结构完整，头部扭转方向的对侧大脑半球前中央区的P22-N30波幅比明显高于对侧，提示患者对侧大脑皮层前中央区电活动存在异常的兴奋及抑制，即抑制性减弱，兴奋性增高，N30记录的是刺激正中神经SEP中长潜伏成分，可能来源于运动辅助区，进一步提示患者存在感觉一运动整合功能异常。

A study of somatosensory evoked potential in patients with spasmodic torticollis

Objective：To explore the function change of cerebral cortex in patients with spasmodic torti collis （ST）by somatosensory evoked potential（SEP）. Methods： SEP was investigated in 30 patients with ST and 30 normal subjects. Bilateral P22 and N30 latencies and P22-N30 amplitude of SEPs were recorded after stimulation to median nerves in 30 patients with ST, P22-N30 amplitude were recorded too after stimulation of median nerve in 30 normal subjects while their head turned to right. Results： All ST patients presented normal latencies of P22 and N30, ipsilateral latency and contralateral latency were not different from each other in statistics. An apparent mean P22-N30 amplitude increased above the hemisphere contralateral to the direction of head deviation. The mean side-to-side ratio of the precentral P22 N30 component amplitude was not different in heathy control subjects. Conclusion： By means of SEPs, normal latencies of P22 and N30 indicates that the structure of conduction pathway is normal, and that the mean value of the PZ2 N30 amplitude in contralateral to head deviation was significantly higher than that of the opposite side. The abnormality could be a heightened excitability of the cortical region that generates the P22-N30 complex and the N30 peak registered in the precentral corticalarea in the hemisophere contralateral to the direction of head deviation. N30 may be based on supplementary motor area and patients with ST may have faulty pro-cessing within the lemniscal pathway with abnormalities in the sensory- motor integration.