0079 The Effects of a Single Night of Continuous Positive Airway Pressure on Memory in Patients with Obstructive Sleep Apnea

Introduction During sleep-dependent memory consolidation, new memories are stabilized for long-term storage in a discriminatory fashion, as memories relevant for future behavior are preferentially processed over others. Memory deficits have been observed in patients with obstructive sleep apnea (OSA) and may result from deficient sleep-dependent memory consolidation. This study investigated the effect of a single night of continuous positive airway pressure (CPAP) on memory consolidation for future-relevant versus future-irrelevant memories in treatment-naïve OSA patients (no-CPAP group) and OSA patients receiving their first night of CPAP treatment (CPAP group). Methods Before sleep, all participants completed two study/test cycles of an object-location memory task. During study, objects from two categories were each presented in one of eight possible screen locations. During test, each object appeared centrally, and participants indicated the screen location where the object was studied. Participants also rated their confidence in each decision. Next, participants were informed that they would receive additional compensation if their memories from one (reward-relevant category) of the two studied categories improved overnight. Sleep was monitored via polysomnography, and participants in the CPAP group received CPAP treatment during sleep. After waking, participants again completed the test phase of the memory task. Results Both groups showed better memory accuracy on the evening test compared with the morning test, with no group differences. Furthermore, both groups showed better retention of reward-irrelevant compared with reward-relevant items. However, while memory confidence decreased in both groups from evening to morning, the no-CPAP group showed a greater decrease for reward-irrelevant compared with reward-relevant items. No significant group differences in sleep measures were present, although relationships between memory and specific sleep measures differed between groups. Conclusion The instruction regarding future relevance was more effective in the no-CPAP group, suggesting that consolidation may have been less disrupted in the no-CPAP group than in the CPAP group. Therefore, a single night of CPAP may not be sufficient to improve memory, perhaps due to the initial difficulty of adjusting to CPAP use. Support (If Any) None