Electrophysiological studies in cervical spondylosis.

This paper reports a study of 57 patients with cervical spondylosis who underwent nerve conduction velocity (NCV), cervical somatosensory evoked potentials (CSEP), and concentric needle electromyography (EMG) as an aid to diagnosis. The results were analyzed in two groups. In Group I, there were 24 patients with radiological changes of cervical spondylosis in the absence of clear neurological signs. Nine patients in this group had abnormal electrophysiological recordings. In Group II, there were 33 patients with clinical signs, and 22 had abnormal electrophysiological recordings. The CSEP was abnormal in 12 of 14 patients who had evidence of nerve root filling defects on myelography. It is concluded that NCV, CSEP, and concentric needle electromyography are useful tests in distinguishing between root lesions and peripheral entrapment neuropathy. Although the methods available are not sufficiently precise to localize the level involved, they can be used as a screen prior to myelography or enhanced computed tomography (CT) scanning if surgery is proposed.