Evaluation of cervical spondylotic myelopathy using somatosensory-evoked potentials.

Fourteen patients who had cervical spine surgery for cervical spondylotic myelopathy with median-nerve short-latency somatosensory-evoked potentials (SSEP) were followed preoperatively and until six months postoperatively. We evaluated the N18 latency and compared it with the JOA score recovery rate for each period. Seven patients demonstrated improvement in the N18 latency immediately following the operation and showed improvement of upper- as well as lower-extremity function 12 weeks postoperatively. We found a statistically significant correlation between improvement in the SSEP during the early decompression period and a good surgical outcome at 12 weeks postoperatively. We conclude that evaluating the median nerve SSEP is useful for prediction of the prognosis in patients with cervical spondylotic myelopathy treated surgically.