Impact of obstructive sleep apnea on cerebral blood flow

Abstract

Obstructive sleep apnea (OSA) is a common disorder with growing incidence. Major risk factors for OSA are obesity, aging, gender and menopause. As life expectancy lengthens and the obesity epidemic is ongoing, we can assume that OSA will affect an increasing part of the population. Pathological consequences of this disease include an increased risk of arterial hypertension, coronary artery disease, arrhythmia, heart failure as well as cerebrovascular diseases, such as stroke, transient ischemic attack and cognitive dysfunction. The cerebrovascular system differs significantly from other vessels in the body. Brain oxygen demands constitute about 20% of the total oxygen consumed by the body. OSA significantly affects the cerebral blood flow both during sleep and daily activities. This can have serious health consequences and makes the brain more vulnerable to ischemia. In this review we describe the impact of OSA on cerebral circulation during both sleep and wakefulness and we also outline the pathophysiology of these changes. In patients with other risk factors for cerebral ischemia, early screening and treatment for OSA should be introduced.