Sleep Apnea Hurts Spatial Memory
Sleep apnea, which is a sleeping disorder characterized by disrupted breathing throughout the night, can negatively affect memory development, a new study reported. Researchers conducted a small study and found that sleep apnea can make it hard for people to remember easy things, such as where they left their house keys.
"We've shown for the first time that sleep apnea, an increasingly common medical condition, might negatively impact formation of certain memories, even when the apnea is limited to REM sleep," study leader Dr. Andrew Varga, a clinical instructor of medicine in the division of pulmonary, critical care and sleep medicine at the NYU Langone Medical Center in New York City, said in an university's news release reported by WebMD. "Our findings suggest memory loss might be an additional symptom for clinicians to screen for in their patients with sleep apnea."
For this study, the researchers recruited 18 people who were diagnosed with severe sleep apnea. They examined the participants when they were asleep during two sessions, which were separated by roughly two weeks. During one of the two nights, the participants were allowed to sleep with their CPAP machine, which is a device that treats sleep apnea. During the other night, the machines was either turned off or reduced. Before and after the participants slept, they had to complete a video game maze.
The team found that their medical condition adversely affected their REM (rapid eye movement) sleep, which is the deepest level of sleep. The disruptions seen in REM sleep as well as other stages of sleep appeared to impact the patients' spatial memory. For example, participants who slept without a fully working CPAP machine performed worse on the video game maze. Spatial memory involves recording data about one's environment and its spatial orientation.
"The thought is that you need both (deep and shallow sleep)," Dr. Varga said according to FOX News. "If you don't have one or the other, you don't' have the ability to consolidate the information."
He added, "Apnea is very common and has a variety of deleterious effects that have to do not only with cardiovascular health, but also there is an emerging dataset - of which this paper is only one piece - to suggest there are really cognitive effects also."
The study, "Apnea-Induced Rapid Eye Movement Sleep Disruption Impairs Human Spatial Navigational Memory," was published in the Journal of Neuroscience.