Transcranial electrical motor evoked potentials as a prognostic indicator for motor recovery in stroke patients. Transcranial electrical motor evoked potentials (MEP) were examined in 33 patients within three days after stroke. Normal values for MEP and motor central conduction time (CCT) were obtained in 46 healthy controls whose MEPs were evaluated during slight voluntary muscle contraction and at rest. Two months later 23 patients were re-examined clinically and electrophysiologically. Motor function change was correlated with MEP results. Two months after stroke the patients with normal or prolonged CCT had an improved motor function compared with those with absent CCT. MEP may be a valuable prognostic indicator in the acute stage of paralytic stroke for recovery of motor function. 