Obstructive sleep apnea: Brain hemodynamics, structure, and function

This paper summarizes a review of articles that have explored the relationship between obstructive sleep apnea (OSA), brain infractions, and cognitive dysfunction. The anomalies in brain hemodynamics, brain atrophy, and cognitive dysfunction resulting from OSA are reviewed. The effectiveness of continuous positive airway pressure (CPAP) treatment on the reversibility of structural and neurobehavioral deficits is also presented. The articles were selected based on a systematic search on PubMed and Medline databases using the key words “sleep apnea, OSA, hypoxia, sleep fragmentation, cerebral hemodynamics, metabolism, brain structure, cognition, memory, quality of life, neuropsychological deficits, and CPAP treatment.” The review suggests that OSA-mediated brain hemodynamics and brain atrophy are concomitant with cognitive dysfunction. It is concluded that OSA results in cerebral hemodynamic instability, hypoxia, and sleep fragmentation which appear to be the major contributing factors to the brain structural changes and cognitive deficits. Furthermore, the reviewed studies indicate that CPAP treatment may partially reverse or diminish the adverse effects of OSA on the brain structure and function. Additional investigations are urgently needed to elucidate the underlying mechanisms of the effects of OSA on the brain and the efficacy of CPAP therapy for brain protection.