Value of somatosensory and motor evoked potentials in predicting arm recovery after a stroke

Objectives-Prediction of motor recovery in the arm in patients with stroke is generally based on clinical examination, However, neurophysiological mea sures may also have a predictive value. The aims of this study were to asse ss the role of somatosensory (SSEPs) and motor (MEPs) evoked potentials in the prediction of arm motor recovery and to determine whether these measure s added further predictive information to that gained from clinical examina tion. Methods-Sixty four patients who had had a stroke and presented with obvious motor deficit of the arm were examined in terms of three clinical variable s (motor performance, muscle tone, and overall disability) and for SSEPs an d MEPs. Clinical and neurophysiological examinations were done at entry to the study (2 to 5 weeks poststroke), and at about 2 months after stroke. Fu rther clinical follow up was conducted at 6 and 12 months after stroke. Results-Neurophysiological measures made in the acute phase were of little use alone in predicting motor recovery of the arm at 2, 6, and 12 months af ter stroke. At 2 months, the absence of SSEPs and MEPs indicated a very poo r outcome. Conversely, if the responses were preserved, a great variation i n motor outcome was found. Multiple regression analysis showed that the add ition of SSEPs and MEPs to the clinical examination increased the possibili ty of predicting arm recovery in the long term. In the acute phase, the com bination of the motor score and SSEPs were best able to predict outcome. Th e long term outcome based on variables taken at 2 months, was best predicte d through incorporating the three clinical measures and MEPs. Conclusions-Neurophysiological measures alone are of limited value in predi cting long term outcome. However, predictive accuracy is substantially impr oved through the combined use of both of these measures and clinical variab les.