BACKGROUND: Training interventions to restore upper extremity (UE) function after a stroke often produce variable outcomes because of their generic nature. In this study, we aimed at determining whether an individualized strengthening program based on integrity of the corticospinal tract, as reflected in the amplitude of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation, could lead to more optimal outcomes in terms of UE function in chronic stroke patients. 

METHODS: A clinical (Fugl-Meyer Assessment__FMA), and a neurophysiological (MEPs (µV) of affected wrist/hand muscles) evaluations were performed. Based on their MEPs amplitude, participants were stratified into three groups of training intensity levels: 1) low: MEPs <25µV; 2) moderate: MEP 50-120µV; and 3) high: MEP >120uV. Training intensity was based on the one-repetition maximum (1RM). Low, moderate and high intensity groups trained at 35-50%, 50-65% and 70-80% 1RM, respectively. Participants trained for 4 weeks, 3X/week. Post-training, subjects rated their UE’s perceived change.

RESULTS: Preliminary observations from three participants (1 subject per training group) who completed the training indicate that all experienced gains at the FMA (mean 5±5 points). Also, all reported subjective improvement in the function of their UE (“much improved” (group #2) to “very much improved” (groups #1/#3)).

DISCUSSION/CONCLUSION: Although still preliminary, these results suggest that adjusting intensity of training based on neurophysiological markers of corticospinal tract integrity could lead to more optimal outcomes in terms of gains in arm function post-stroke

AN INDIVIDUALIZED APPROACH FOR UPPER EXTREMITY TRAINING POST-STROKE BASED ON NEUROPHYSIOLOGICAL MARKERS: PROCEDURES AND PRELIMINARY OBSERVATIONS