Patients who use their CPAPs 6 or more hours per night are nearly eight times as likely to demonstrate normal memory abilities compared to patients who used their inconsistently.
A common symptom of Obstructive Sleep Apnea (OSA) is memory loss. Certain stages of sleep are known to be important for brain repair, such as turning short-term memory into long term memory. Sleep apnea sufferers experience memory loss due to the repeated interruptions to sleep caused by obstructive apneas and oxygen reduction. This sleep fragmentation can adversely affect normal brain repair and function.
A study published by Zimmerman and colleagues in the December issue of Chest* examined the degree to which varying levels of CPAP adherence improved memory in 58 memory-impaired patients with clinically diagnosed OSA. After treatment with CPAP, patients were divided into three groups based on their three-month treatment adherence: (1) poor users (14 subjects), patients who averaged fewer than two hours/night of CPAP use; (2) moderate users (25 subjects), patients who averaged two to six hours/night of CPAP use; and (3) optimal users (19 subjects), patients who averaged more than six hours/night of CPAP use.
The results demonstrate that patients with OSA who were memory-impaired before treatment established normal memory performance following 3 months of optimal CPAP use. The improvements in memory varied based on CPAP adherence. Subjects who were optimal CPAP users were nearly eight times as likely to demonstrate normal memory abilities compared with subjects who used their CPAP for two or fewer hours per night. *(Zimmerman et al, Normalization of memory performance and positive airway pressure adherence in memory impaired patients with obstructive sleep apnea. Chest 2006;130:1772-1778).