Clinical Correlation Between Motor Evoked Potentials and Gait Recovery in Poststroke Patients

Abstract

Piron L, Piccione F, Tonin P, Dam M. Clinical correlation between motor evoked potentials and gait recovery in poststroke patients. Objective To evaluate, in patients with a stroke in the area of the middle cerebral artery, whether transcranial magnetic stimulation values from the affected lower limb correlated with the degree of gait recovery. Design The prognostic evaluation in subjects with complete lower-limb palsy, inability to walk, and dependence in the activities of daily living, 1 month after vascular injury. Setting University-affiliated rehabilitation hospital. Participants Twenty consecutive patients (12 women, 8 men) were enrolled 1 month poststroke (30±5d); all patients concluded the rehabilitation program, which lasted 6 months. Intervention Barthel Index score, Hemiplegic Stroke Scale (HSS) score, and motor evoked potentials (MEPs) from the tibialis anterior muscle were performed 1, 4, and 7 months poststroke. The Wilcoxon signed-rank test, Mann-Whitney U test, and Spearman rank-order correlation coefficient were employed. Main Outcome Measures The independence of gait defined as an HSS gait score of 3 or less (ability to walk without assistance apart from a stick or cane). Results Patients with no recordable MEPs 1 month poststroke never regained walking ability; patients with MEPs of 8% or more (13.11±5.95) regained independent gait at discharge. It was not possible to predict walking capacity in patients with MEPs less than 8% (4.0±1.41). Four months postinjury, walking capacity was achieved only by the patients with MEPs of 18% or more (23.1±6.2). Conclusions In the postacute phase of stroke, the lower-limb MEP amplitudes could be a supportive tool for prognosis of lower-limb motor outcome.