Impact of obstructive sleep apnea on cognitive performance

OBJECTIVE: To evaluate the impact of obstructive sleep apnea (OSA) on cognition. METHOD: We compared the performance of 17 patients with polysomnographic diagnosis of OSA in brief cognitive tests to that of 20 healthy controls, matched for age and education. The testing battery included the Mini-Mental State Examination (MMSE), Brief Cognitive Screening Battery (BCSB), Digit-Symbol (DS) and Phonemic Verbal Fluency (FAS). Anthropometric measures and scores from the Epworth Sleepiness Scale were also recorded. RESULTS: OSA patients performed significantly worse than controls in the MMSE, in memory items from the BCSB, in DS and also in FAS. OSA patients also exhibited higher body mass index, increased neck circumference and higher scores in Epworth Sleepiness Scale than controls. CONCLUSION: OSA significantly impairs cognitive performance, especially within the domains of attention, memory and executive functioning. These deficits may be detected by brief and easy-to-administer cognitive tests.