Pectoralis major motor evoked potentials in cervical spondylosis

Myelopathy is a severe complication of cervical spondylosis (CS). We studied 27 consecutive patients with CS referred for evaluation for possible myelopathy using transcranial magnetic stimulation. The findings were compared with those from 20 normal controls. Magnetic resonance imaging was utilized to assess the degree of cord compromise. Central motor conduction time (CMCT) abnormalities showed equivalent diagnostic yield with pectoralis major (PM) recordings, as compared with combined first dorsal interossei and abductor hallucis recordings. Our findings show that CMCT measurement with PM recordings is of value as a diagnostic adjunct in the electrophysiological evaluation of myelopathy in CS.