Motor Evoked Potentials as a Prognostic Indicator in Stroke Patients with Motor Deficit

Ma, Hyeo Il; Lee, Sang Ahm; Kim, Jong Sung; Kim, Kwang Kuk; Lee, Myoung Chong

Abstract

Since the development of magnetic stimulation as a way of assessing the functions of corticospinal pathways, diseases involving central motor pathways have been investigated by motor evoked potentials(@). However, studies correlating MEP findings and the neurological deficits were rarely carried out in patients with stroke. In this study, transcranial magnetic stimulation of the motor cortex and lower cervical area was performed in 50 patients with acute stroke and 23 healthy volunteers. Follow-up tests were performed in 22 patients about I month@ later. The amplitudes of @ were significantly reduced (P=0.0001), and central motor conduction time (CMCT) was significantly delayed (P=0.0004) in stroke patients compared to the normal controls. The abnormalities of MEP were closely related to the initial motor deficits. The cortical MEP findings in patients with cortical infarction and pontine infarction were more severe than those obtained in patients with subcortical I lesion. Initial MEP findings showed good correlation with the final functional outcome of the patients. The shortened latencies of follow-up MEP were significantly (P=0.0266) related to the improvement of the patients' motor deficit. These results illustrate that the results of magnetic stimulations are related to the prognosis of patients with stroke, and suggest that MEP may be I used in the monitoring their neurological or functional progress.