Are you on CPAP? Did you have symptoms beforehand that disappeared after one night of treatment? Or did it take a while before you started to feel better? Some claim that just one night (or a few hours) of treatment can help them feel more like a human again, while others require a few weeks or months of treatment in order to feel a difference. With this idea in mind, a team of researchers set out to test whether short-term and long-term CPAP treatment could improve cognitive functioning when compared to cognitive functioning prior to treatment.
The research team, based in Taiwan, used participants who had suspected sleep apnea for this study. They were individuals who had come to the sleep lab with complaints of excessive snoring. These individuals underwent an overnight sleep study to assess the presence and severity of sleep apnea, and those who qualified were entered into the study and assigned to CPAP (technically it was C-Flex, which is a version of CPAP). After 3 months on CPAP, participants were brought back to the sleep lab for further testing.
Cognitive testing occurred at three time points: before treatment began, after 1 night of CPAP treatment, and after 3 months of CPAP treatment. Of course, not everybody actually uses their CPAP, so treatment compliance was obtained from microchips located inside the machine. Those who used their CPAP more than 70% of the time were considered good users, and those who used their CPAP less than 50% of the time were considered poor users. All in all, 14 subjects were available for follow-up analysis after 3 months of treatment, and 6 of these subjects were considered poor users.
Cognitive testing included subtests of the CANTAB test, which allows for the assessment of four different types of cognition: attention, visual memory, decision-making, and working memory (short-term memory).
Results showed that following 1 night of CPAP treatment, compared to cognitive functioning in before-treatment testing, scores had improved in the attention and decision-making domains. It was also found that these scores tended to keep improving all the way through 3 months of treatment. Additionally, some subdomains that did not improve after 1 night of treatment did improve after 3 months, including a few visual memory and decision-making tasks. When comparing good and poor CPAP users after 3 months, the good users had better performance on the decision-making tasks, perhaps not surprisingly.
This study is incredibly interesting, as it compares the short-term and long-term cognitive effects of treating sleep apnea with CPAP. As you may know, CPAP is the gold standard treatment for sleep apnea, and for good reason. CPAP can partially or fully eliminate apneas. In this way, individuals can essentially sleep like a non-apneic. This study also offers hope for those who may not feel the immediate consequences of using CPAP. If you have trouble sticking to your treatment, just remember that sometimes it takes a few months before you feel the full effects! So don’t give up!
Lin, S. W., Chou, Y. T., Kao, K. C., Chuang, L. P., Yang, C. M., Hu, H. C., ... & Chen, N. H. (2014). Immediate and Long-term Neurocognitive Outcome in Patients with Obstructive Sleep Apnea Syndrome After Continuous Positive Airway Pressure Treatment. Indian Journal of Otolaryngology and Head & Neck Surgery, 67(1), 79-85.