Neurophysiological investigation of cervical spondylosis.

The difficulties in diagnosing spinal cord lesions due to the cervical spondylosis is well-known in clinical neurology. In order to investigate the contribution of various neurophysiological examinations in the diagnosis in cervical spondylosis, we examined 70 patients suffering from cervical spondylosis, with peripheral nerve conduction studies, F-wave from the upper limb and electromyography from the corresponding muscles, as well as somatosensory evoked potentials (SEPs) from upper and lower limbs. Patients were separated into four groups: 20 patients had cervical spondylosis symptoms only; 15 patients had symptoms and signs of spinal root involvement; 15 patients had symptoms and signs of myelopathy; and 20 patients had symptoms and signs of both myelopathy and spinal root involvement. A group of 20 normal controls was also studied. In all groups of patients SEPs were the most sensitive electrophysiological study. Low-amplitude N13 and increased conduction time of N9-N13 and central conduction N13-N19 and LP-P27 were the most common finding in SSEP testing. SEPs were affected in many cases without CT-MRI findings of spinal cord pressure. From the above findings, SEPs proved to be the most sensitive diagnostic investigation in cervical spondylosis.