Effect of Continuous Positive Airway Pressure (CPAP) on Cognitive and Functional Performance in Stroke Patients With Obstructive Sleep Apnea

Stroke occurs as a result of ischemic injury to neural tissue, as a result of cardiogenic or artery to artery embolism or intracranial arterial thrombosis. The traditional vascular risk factors, namely hypertension, diabetes mellitus, tobacco smoking, family history and hyperlipidemia as well as atrial fibrillation are major determinants of stroke risk. Obstructive sleep apnea (OSA) has been shown to be a risk factor for hypertension and,although the association is less strong, atherosclerotic heart disease.There is a high prevalence of OSA amongst stroke patients, on the order of 60 to 70%, which is tenfold higher than in the general healthy population. Recently, it has been shown that, in stroke patients undergoing inpatient rehabilitation,the presence of OSA predicts both a poor functional outcome and greater length of hospitalization in the rehabilitation unit, even after adjustment for stroke severity. 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.