Longitudinal Study of Motor Evoked Potential in Patients with Acute Ischemic Stroke

J Korean Neurol Assoc > Volume 17(5); 1999 > Article

Journal of the Korean Neurological Association 1999;17(5): 631-636.

급성 허혈성 뇌졸중 환자에서 운동유발전위 검사의 추적조사

홍 찬, 김종열 ·서정규

경북대학교 의과대학 신경과학교실

Longitudinal Study of Motor Evoked Potential in Patients with Acute Ischemic Stroke

Chan Hong, M.D., Jong Yeol Kim, M.D., Chung Kyu Suh, M.D.

Department of Neurology, School of Medicine, Kyungpook National University

Abstract

Background : The prognostic value of motor evoked potentials(MEP) by transcranial magnetic timulations(TMS) in acute stroke has not been well established. To determine the value of MEP as predictors of motor and functional recovery we examined correlations of neurophysiological measurements of central motor conduction time(CMCT) and functional assessments. Methods : A longitudinal study was performed on 32 first-ever acute ischemic stroke patients. The cortical and cervical motor evoked potentials(MEPs) along with the degree of extremity weakness, the NIH stroke scale, and the Barthel index were performed in the period immediately following stroke and after 3-4 months of the onset. Results : Five groups of patients were divided on the basis of MEP responses following the cortical stimulation; initial normal response following the normal one (group Ⅰ; 11), initial delayed response following a normal or still delayed one (group Ⅱ; 3/group Ⅲ; 0), and an initial absent response with the reappearance of CMCT or still absent one (group Ⅳ; 8/group Ⅴ; 10). Patients in group Ⅰ,Ⅱand Ⅳhad consistently lower scores in motor weakness degree and NIH scale and higher scores in the Barthel index both at initial and follow-up studies, and achieved significantly better functional recovery(p<0.01). Conclusions : Discordant results of MEP in predicting the prognosis of stroke may result from the disregard of group Ⅳ, which had previously been considered as a poor outcome group solely because no corti-cal MEP responses were recorded at the initial study. As the MEP alone during the acute stage could not differentiate group Ⅳfrom group Ⅴwhich had a persistent absence of cortical MEP responses, the evaluation of the neurological deficit at the same time is needed for better prediction of prognosis.J Kor Neurol Ass 17(5):631~636, 1999 Key Words : Evoked potential, Motor, Prognosis, Ischemic, Stroke