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+/-5 d); 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.