胫后神经体感诱发电位对脊髓病变的定位诊断

Posterior tibial nerve somatosensory evoked potential in topical diagnosis of different segmental spinal cord lesions

目的：研究胫后神经体感诱发电位对脊髓病变的定位诊断价值。方法：通过经皮恒流电刺激胫后神经，采用髂棘、脐部和头皮Fpz作参考电极，分别于第4腰椎棘突、第12胸椎棘突和头皮Cz’置记录电极，依次记录CE、N24和P40电位之峰潜伏期。共检测15例健康成人和29例经核磁共振证实的腰骶神经根或脊髓病变患者。结果：①CE、N24和P40电位均异常，见于腰骶神经根病变；②CE正常，N24和P40异常，见于腰骶髓病变；③CE、N24正常，P40异常，见于颈胸髓病变。结论：胫后神经体感诱发电位能够鉴别腰骶神经根或不同节段的脊髓病变，临床上具有定位诊断价值。但对于轻度的腰骶神经根或脊髓腹侧病变，结果可出现“假阴性”。

Objectives: To study the Significance of the for of different segmental spinal cord lesions by means of the posterior tibial nerve somatosensory evoked potential (SEP) .Methods: The peak latereies of caoda equina(CE), N24 and P40 were successively recorded by a constant elearic stimulation in the posterior tibal nerve,and the recording for were placed respectively on the spinal processes of vertebrea, the 12th thoracic vertebrea and the scalp with the reference to tha iliac crest, the umbilius and Fps. Fifteen normal subjects and 29 patients with lumbosacral radiculopathy or spinal cord lesions confirmed by magnetic resonance imaging (MRI) were studied.Results: Abnormal CE, N24 and P40 were for in patients with iumbosacral radiculopathy, normal CE with abnormal N24 and P40 in patients with lumbosacral cord lesions and normal CE and N24 with abnormal P40 in patients with the lesions from the cervical to the thoracic spinal cords.Conclusions: Lumbosacral radiculopathy and different spinal cord lesions could be differentiated through posterior tibial nerv SEP, and it might be of certain significance in the topical diagnosis. However, false negative SEP could be observed in patients with less severe lumbosacral radiculopathy or in the vntral spinal cord lesions.