Relationship of National Institute of Health Stroke Scale and Motor Evoked Potentials in Subjects with Stroke

ABSTRACT

OBJECTIVE: To investigate the relationship between National Institute of Health Stroke Scale (NIHSS) and motor evoked potential (MEP) after stroke, measured by transcranial magnetic stimulation (TMS). METHOD: Forty six subjects with the middle cerebral artery ischaemic/hemorrhagic stroke were examined with NIHSS and TMS. According to the responsiveness of MEP in the affected muscles, subjects were divided into 2 groups Group I consisted of 26 subjects responsive to TMS of the affected hemisphere and group II, 20 subjects unresponsive to TMS. NIHSS score was expressed as a sum of NIHSS total score, NIHSS arm and leg subscore. RESULTS: The resting motor threshold (rMT) and the amplitude of MEP in group I were 75.1% and 13.5 uV, respectively. Although NIHSS leg subscore was no statistical difference between two groups, NIHSS total score and NIHSS arm subscore in group I were statistically lower than those in group II. In group I, the rMT had a correlation with NIHSS total score and NIHSS arm subscore (r=0.39, r=0.49, p0.05). CONCLUSION: The NIHSS has relationship with cortical neurophysiological changes in the affected cerebral cortex in stroke. Therefore, it would be a useful tool to evaluate the status of motor function of hemiplegic stroke.