We propose to examine the effect of CPAP therapy on the neuropsychological and functional outcomes of stroke patients with OSA admitted to the Toronto Rehabilitation Institute Stroke Rehabilitation Unit in a prospective, randomized study. We hypothesize that, in stroke patients with OSA, CPAP therapy will improve indices of vigilance, attention, and cognitive performances well as motor function(as it does in OSA patients without stroke)when compared to those not treated with CPAP. Furthermore,we hypothesize that the outcome of rehabilitation, as assessed by neuropsychological and motor indices, will be improved in these patients.