Magnetic transcranial motor and somatosensory evoked potentials in cervical spondylitic myelopathy.

Fourteen cervical spondylitic myelopathy (CSM) patients were clinically diagnosed and proved by MRI and surgery. The results of 11 patients showed that 8 (72.7%) had motor evoked potential (MEP) abnormality with prolongation of central motor conduction time (CMCT) in 7, and absence of motor action potentials after C7 stimulation in one. Five of the 11 patients showed normal somatosensory evoked potentials (SEPs) along the same arm. The short term (2-4 weeks) follow-up study in 10 patients showed normalization of the prolonged CMCT in one and reappearance of MEPs with C7 stimulation in another. Non-invasive and painless magnetic transcranial stimulation of the motor pathways is useful in the assessment and management of CSM patients, and is better than electrical stimulation.