Motor evoked potentials with magnetic stimulation: correlations with height.

The relationship between height and motor evoked potentials (MEPs) was studied in 52 healthy young subjects. Evoked responses from the abductor digiti minimi and tibialis anterior muscles were obtained following magnetic stimulation over the vertex and the cervical and lumbar regions. The latencies of MEPs were highly correlated with height. The conduction time from the motor cortex to the lumbar region was also correlated with height, but that from the motor cortex to the cervical region was not. It is concluded that height is an important variable in defining the MEP normality.