Concerning the mechanism of recovery in stroke hemiplegia.

Two patients with pure motor hemiplegia were regaining strength in the affected limbs when a pure motor stroke developed on the opposite side. At the same time as the new hemiplegia appeared, the recovering side became re-paralyzed, suggesting that activity in the contralateral corticospinal tract had participated in the recovery process. Pathological studies were confirmatory. The literature pertaining to contralateral motor compensation is reviewed.