正常小儿胫神经诱发脊髓电位特征和脑瘫小儿该电位的变化

CHARACTERISTICS OF SPINAL CORD EVOKED POTENTIAL FOLLOWING POSTERIOR TIBIAL NERVE STIMULATION IN NORMAL CHILDREN AND ITS CHANGES IN CHILDREN WITH CEREBRAL PALSY

采取刺激后胫神经(PTN)诱发叠加技术,利用体表无创伤性双极记录方法观察了16例正常小儿和43例脑瘫小儿的脊髓诱发电位(SCEP)。正常小儿的SCEP自下而上潜伏时逐渐延长、电压减小。从椎体C6到T10表现为Pa-Na-Pb三相波,T10～T12为Pa-Na1-Na2-Pb波,T12～L4为多相复合波。左右侧SCEP波形相似,潜伏时、电压相同,它们之间无统计学显著差别;但不同节段之间SCEP差异显著;脊髓传导速度为57.14m/s。脑瘫小儿SCEP正常者占14％;全髓反应低下者占20％;左右侧反应不对称者占46％;节段性反应低下者占15％;其它异常约占5％。不但节段间存在显著差异,而且全脊髓左右侧电压间以及颈、腰骶髓的潜伏时间出现显著差异。脊髓传导速度减低(患侧46.22m/s,对侧53.48m/s)。结果提示:(1)正常小儿脊髓活动左右对称,不同脊髓节段对PTN刺激反应不同。(2)脑瘫小儿脊髓活动左右不对称,一侧功能下降时对侧有一定代偿力,脊髓传导速度减慢。

Spinal cord evoked potential (SCEP) elicited by posterior tibial nerve (PTN) stimulation was recorded with surface bipolar electrodes placed over the regions corresponding to the lumbosacral, thoracic and lower cervical spine in 16 normal children and 43 children with cerebral palsy (CP).In normal children, the SCEP of right and left sides of spinal cord was symmetrical, the latencies of SCEP lengthened gradually and amplitudes decreased with distance from the caudal to cephalic ends of the cord. Pa-Na-Pb triphasic potentials at C6-T10 of the spine, Pa-Nal-Na2-Pb waves at T10-T12, complex potential over the lumbosacral and the caudal parts were recorded. The latencies and amplitudes showed no significant difference between the responses elicited by stimulating the left and right PTN , but had statistically significant difference (P<0.01) between different segments of the spinal cord. The conduction velocity from sacral to the lower cervical spinal cord was about 57.14m / s.In children with CP, SCEP was normal in 14% of patients and abnormal in 86%, including decrease in response of whole spinal cord in about 20%, asymmetrical responses of right and left sides in about 46%, lowered response of certain segment in about 15% and other abnormal changes in about 5%. The SCEP was not only different signifcantly between different segments of the spinal cord but also different in amplitude between left and right sides and different in latencies between lower cervical, lumbar and sacral segments. The conduction velocity of spinal cord was lower in CP children than in normal children ( 46.22m / s vs 53.48 m / s ).