Prediction of Clinical Outcomes in Patients with Acute Ischemic Stroke by Measurements of Motor Evoked Potentials

Seo, Yeong Bae; Lee, Ju Kang; Shin, Dong Jin; Lee, Yeong Bae

Abstract

OBJECTIVE
The integrity of the motor pathways can be assessed objectively and quantitatively by measuring the motor evoked potentials (MEPs). However, the early prognostic application of MEPs for assessing the motor and functional recovery of patients with acute ischemic stoke has yielded contradictory results. Therefore, we assessed the value of MEPs for predicting the clinical outcomes of acute ischemic stroke patients.
METHODS
Thirty three stroke patients with different degrees of hemiparesis were enrolled in this study. The stroke severity and outcome were assessed using the National Institute of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) at admission and at 3 months. The MEPs were measured at the adductor pollicis brevis and adductor hallucis muscles and the relationships between the NIHSS, the mRS and the MEP findings were analysed.
RESULTS
In the acute phase of stroke, the presence of MEPs in the upper or lower extremities was correlated with a better clinical outcome (NIHSS: 9.12+/-5.86->2.81+/-1.47, mRS: 2.81+/-1.47->1.62+/-1.31) than the absence of an MEP in at least one extremity (NIHSS: 11.47+/-5.53->8.88+/-6.02, mRS: 3.70+/-1.31->2.94+/-1.67). Especially, there was significant clinical improvement after 3 months in the large territorial infarction patients according to the presence of MEPs. The sensitivity of the presence of MEPs for predicting clinical improvement (motor grade> or =III) was 71.4%, while the specificity was 72.7% in severe hemiplegic patients (motor gradeCONCLUSION
It seems justified to use MEPs to predict the prognosis of large territorial infarction patients who suffer with severe hemiplegia (motor grade