Motor Evoked Potentials in Acute Cerebral Infarction: Correlations with Muscle Strength, Babinski Sign, and Hyperreflexia

The relationship between motor evoked potentials (MEPs) and common motor signs in stroke were studied in 100 patients within a mean of 7.5 days after cerebral infarction. Magnetically evoked motor responses were classified into type 1, normal response; type 2, prolonged central motor conduction and/or decreased response amplitude; and type 3, absent response. MEPs were highly correlated with muscle strength. The transition from type 1 to type 2 response was the muscle weakness of 4/5, and the transition from type 2 to type 3 response was the muscle weakness of 3/5 for the upper limb and 2-3/5 for the lower limb. MEPs also had a good correlation with Babinski sign, and the transition between the presence and the absence of this motor sign was the type 2 response. There was a correlation between MEPs and hyperreflexia for the upper limb, but not for the lower limb. It is concluded that MEPs are useful in the evaluation of motor function abnormalities in acute stroke.