Benefits of Treating Obstructive Sleep Apnea in Cognition: Systematic Literature Review

Introduction: Obstructive sleep apnea syndrome (OSAS) is characterized by intermittent hypoxia, sleep fragmentation, daytime sleepiness, cognitive impairment, and brain cell damage due to brain blood flow reduction, with ischemic damage, increased microvascular reactivity, and brain tissue damage. OSAS is strongly linked to chronic, neurodegenerative, and inflammatory cerebrovascular disease and cognitive impairment. Continuous positive airway pressure (CPAP) is the first-line treatment for OSAS. Objective: This article aims to evaluate the effect of CPAP treatment on neurocognitive performance in OSAS patients with mild cognitive impairment or dementia by reviewing the literature. Methods: We performed a comprehensive review of the Portuguese and English languages without a time limit using the following Mesh terms: dementia, mild cognitive impairment, obstructive sleep apnea, and CPAP. We included randomized controlled trials (RCTs), meta-analyses, and systematic reviews (SRs) where the impact of CPAP on neurocognitive performance was addressed. Results: Five SRs and three RCTs reported significant improvements in neurocognitive performance, especially in verbal, visuospatial, and working memory. Conclusion: CPAP treatment seems to improve cognitive defects associated with OSA.