Motor evoked potential changes in ischaemic stroke depend on stroke location.

This study was undertaken to evaluate the central motor conduction in ischaemic stroke and their role in predicting the short term prognosis. Fifty-six patients with CT proven infarction were examined after a mean duration of 9 (range 1-30) days. Patients' mean age was 54.6 years (range 22-80) and 44 of them were males. Motor evoked potentials (MEPs) on cortical stimulation were unrecordable in 57% and central motor conduction time (CMCT) was prolonged in 21% patients. Central motor conduction time was significantly related to the mortoricity index and outcome of the patients, but not to the size of infarction. The involvement of the primary motor area or its connection seemed to be an important determinant of the motor dysfunction, MEP abnormalities and outcome. A recordable MEP on cortical stimulation predicted a better outcome than an unrecordable one. Changes in central motor conduction occurred in 14 out of 33 patients who were followed up for a mean duration of 5.7 months (range 3-15). Improvement in CMCT was noted after 4 weeks in two patients, 5-12 weeks in eight, and after 12 weeks in four patients, highlighting the multiplicity of factors responsible for the recovery.