Sleep apnea may affect memory
New research published in the Journal of Neuroscience suggests that sleep apnea may impair spatial memory even when other sleep stages aren’t uninterrupted. Spatial memory is used for everyday tasks, such as remembering where you parked your car or recalling simple directions to familiar places.
Researchers at New York University's Langone Medical Center built on other studies showing how deprivation of REM sleep had detrimental effects on memory in rodents. To assess cognitive impact of REM sleep apnea, researchers recruited 18 subjects with severe sleep apnea who use a continuous positive airway pressure (CPAP) machine every night.
The subjects spent two nights in the NYU Sleep Disorders Center's sleep lab, during which time they played video games before and after sleep. The subjects were first given a baseline examination using the video games before any observation of their sleep patterns. They used a joystick to navigate through one of two unique, computer-generated 3D spatial mazes. Then, during one night's sleep, subjects used their therapeutic CPAP as they normally would at home. On the other night, their use of CPAP was reduced during REM sleep, allowing sleep apnea to occur. CPAP was maintained at the therapeutic level during all other stages of sleep.
The results showed that when the patients used the CPAP all night, they showed a 30 percent overnight improvement in maze completion time from their baseline examinations. However, when REM sleep was disrupted by sleep apnea, patients took 4 percent longer to complete the maze tests.