REM-related obstructive sleep apnea: when does it matter? Effect on motor memory consolidation versus emotional health.

Study Objectives: The clinical importance of obstructive sleep apnea, which can be prevalent during rapid eye movement (REM) sleep, is unclear. The current study examines the effect of REM-related obstructive sleep apnea on motor memory consolidation as well as on mood states.

Methods: We compared performance on the motor sequence task (MST), psychomotor vigilance test (PVT), Functional Outcomes of Sleep Questionnaire, and the Profile of Mood State (POMS) survey between 3 groups: healthy controls (n = 18), REM-exclusive OSA (n = 17), and patients with OSA with respiratory events throughout REM and non-rapid eye movement (NREM) sleep (n = 18).

Results: As expected, performance on the MST improved overnight in the healthy control group. An improvement which was similar in magnitude was also observed in the REM-exclusive OSA group whereas patients with similar OSA during REM and NREM sleep showed reduced overnight memory consolidation. Consistent with these results, we found a correlation between overnight MST improvement and the apnea hypopnea index during NREM sleep (P = .041), but not during REM sleep (P = .424). However, patients with REM-exclusive apnea demonstrated the most negative emotions based on scoring highest on the POMS survey (P = .019).

Conclusions: Our results provide evidence that although apneas occurring only during REM sleep do not have an effect on the encoding and stabilization of motor sequence memories, they are deleterious for emotional health.