Motor Evoked Potentials in Transverse Myelitis

J Korean Neurol Assoc > Volume 16(3); 1998 > Article

Journal of the Korean Neurological Association 1998;16(3): 353-359.

횡단성 척수염에서의 운동유발전위검사에 대한 연구

김주용, 이광우

서울대학교 의과대학 신경과학 교실

Motor Evoked Potentials in Transverse Myelitis

Joo-yong Kim, M.D., Kwang-woo Lee, M.D.

Department of Neurology, College of Medicine, Seoul National University

Abstract

Background & Purpose : Motor evoked potentials (MEPs) by transcranial magnetic stimulation have been proved to be useful for evaluation of central motor pathway. Although there have been many reports on MEPs in various neurological disorders, MEPs in transverse myelitis have rarely been studied. To know the diagnostic value of MEPs in transverse myelitis, we analyzed MEP findings in patients with transverse myelitis and compared them with the findings of somatosensory evoked potentials (SEPs) and made correlations with clinical features. Methods : Thirteen patients with transverse myelitis affecting thoracic spinal cord were studied. MEPs were recorded from abductor hallucis and SEPs were performed with posterior tibial nerve stimulation. Results : Abnormal MEPs were found in 8 of 13 patients (61.5%); unobtainable or poor MEP in 5 patients (38.5%), prolonged central motor conduction time (CMCT) in 1 patient (7.7%), poor MEP and prolonged CMCT in 1 patient (7.7%), and increased interside CMCT difference in 1 patient (7.7%). Abnormal SEPs were found in 10 of 13 patients (76.9%), which showed higher diagnostic sensitivity than MEP. MEP abnormalities were not always correlated with the clinical severity of the pyramidal tract involvement. Conclusion : MEPs may provide an objective method to assess functional integrity of motor pathway in transverse myelitis, as SEPs are useful in the assessment of sensory pathway along the posterior column of the spinal cord. Key words: motor evoked potential, MEP, transverse myelitis, somatosensory evoked potential, SEP