Inclusion Criteria:  Diagnosis of stroke as defined by the WHO: "a rapid onset event of vascular origin reflecting a focal disturbance of cerebral function, excluding isolated impairments of higher function and persisting longer than 24 hours." Diagnosis of stroke will be confirmed by imaging or clinical diagnosis. Age 18 or older. Admitted to in-patient rehabilitation. National Institutes of Health Stroke Scale (NIHSS) item 1a score <2 (Level of consciousness: 0=alert, 1=not alert, but arousable by minor stimulation to obey, answer, or respond). Provision of informed consent by individual or by legally authorized representative.  Exclusion Criteria:  Pre-stroke or current diagnosis of OSA or other sleep-related breathing disorder. Living in a nursing home or assisted living center prior to the stroke. Unable to ambulate 150' independently prior to the stroke. Other neurologic health condition that may impact recovery such as Parkinson Disease, Multiple Sclerosis, Traumatic Brain Injury, Alzheimer's Disease. Women who are pregnant. Recent hemicraniectomy or suboccipital craniectomy (i.e. those whose bone has not yet been replaced), or any other recent bone removal procedure for relief of intracranial pressure. Planned discharge location >150 miles radius from recruitment site (Upstate Medical University OR Good Shepherd Rehabilitation Network) . Global aphasia as defined by a NIHSS item 9 score of 3 (3= Mute, global aphasia; no usable speech or auditory comprehension). Inability to understand English