Sleep, ageing and stroke--newer directions in management of stroke.

Stroke is a serious health problem and is chiefly a disorder of the elderly population. Several modifiable and non modifiable risk factors have been studied. The association of sleep disorders and stroke is exciting. Obstructive sleep apnea (OSA) which is now considered a systemic disease significantly increases the risk of stroke and death from any cause and the increase is independent of other risk factors including hypertension. There is high prevalence of OSA in the elderly. OSA affects the cerebral hemodynamics adversely. There appears to be a bi-directional relation between sleep disordered breathing(SDB) and cerebrovascular accidents. Strokes can themselves generate SDB. The presence of OSA in stroke patients is associated with poor outcome. Cyclical hypoxia and sympathetic stimulation has deleterious effects on cardiovascular, cerebrovascular and metabolic functions. The effects are particularly important in existing ischemic brain injury. Use of continuous positive pressure in OSA patients is rewarding. We propose that feeding through Ryle's tube may compromise with the patency of pharynx during sleep times and therefore this must be considered in management guidelines for stroke.