Somatosensory evoked potentials in diagnostics of cervical spondylosis and herniated disc.

Somatosensory evoked potentials (SEPs) were recorded in 16 healthy controls and 12 patients suffering symptoms typical of cervical spondylosis and/or herniated disc and showing abnormal findings both in clinical and myelographic examinations. SEP recordings were performed at 3 different levels of the nervous system, at Erb's point, over the 7th cervical spine and at the inion, by stimulating the median nerve separately at both wrists. Nine of the 12 patients were chosen for surgical treatment, while 3 patients received physiotherapy. Six out of the 12 patients showed abnormal findings in SEP recordings, while the 3 patients chosen for the physiotherapy group showed normal SEP recordings. In the present study the amplitudes of the responses may seem to reflect nerve lesions caused by spondylotic deformities more than the latencies of responses. The results suggest that the SEP recordings may have value as a diagnostic aid in cervical spondylosis and spinal stenosis, which finding is in agreement with those of some other authors.