TRANSCRANIAL MAGNETIC STIMULATION IN PATIENTS WITH CERVICAL SPONDYLOTIC MYELOPATHY - CLINICAL AND RADIOLOGICAL CORRELATIONS

Motor evoked potentials (MEPs) were studied in 28 patients with cervic al spondylotic myelopathy. MEPs after cortical stimulation were abnorm al in 27 patients, the responses in the leg muscles being affected the most often. Clinically asymptomatic motor lesions were detected in 7 patients (25%). The central motor conduction time (CMCT) for the abduc tor digiti minimi muscles correlated significantly with the clinical d isability, whereas the radiological findings did not correlate with th e clinical and neurophysiological parameters. In 9 patients MEPs were also recorded in the biceps muscles. The 7 patients with an abnormal C MCT for the biceps muscles had the most severe stenosis at the C-4-C-5 level or higher. The 2 patients with normal MEPs of the biceps muscle s both had a stenosis at the C-5-C-6 level. The results of this study suggest that MEPs are useful for detecting spinal cord dysfunction and for localizing the level of the lesion. Some recommendations regardin g the possible use of MEPs in the clinical evaluation of patients with cervical spondylotic myelopathy are given. (C) 1994 John Wiley & Sons , Inc.