Executive dysfunction in OSA before and after treatment: a meta-analysis.

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a frequent and often underdiagnosed condition that is associated with upper airway collapse, oxygen desaturation, and sleep fragmentation leading to cognitive dysfunction. There is meta-analytic evidence that subdomains of attention and memory are affected by OSA. However, a thorough investigation of the impact of OSA on different subdomains of executive function is yet to be conducted. This report investigates the impact of OSA and its treatment, in adult patients, on 5 theorized subdomains of executive function.

DESIGN

An extensive literature search was conducted of published and unpublished materials, returning 35 studies that matched selection criteria. Meta-analysis was used to synthesize the results from studies examining the impact of OSA on executive functioning compared to controls (21 studies), and before and after treatment (19 studies); 5 studies met inclusion in both categories.

MEASUREMENTS

Research papers were selected which assessed 5 subdomains of executive function: Shifting, Updating, Inhibition, Generativity, and Fluid Reasoning.

RESULTS

All 5 domains of executive function demonstrated medium to very large impairments in OSA independent of age and disease severity. Furthermore, all subdomains of executive function demonstrated small to medium improvements with CPAP treatment.

DISCUSSION

Executive function is impaired across all five domains in OSA; these difficulties improved with CPAP treatment. Age and disease severity did not moderate the effects found; however, further studies are needed to explore the extent of primary and secondary effects, and the impact of age and premorbid intellectual ability (cognitive reserve).