Posttraumatic stress disorder (PTSD) is associated with activation of the brain fear circuitry. Studies of sleep in PTSD provide a unique window into the relation or connection of sleep physiology and autonomic activation. Serial level 3 home sleep apnea tests (HSATs) (10 HSATs over 1 month) in a patient who was medication free, had PTSD, and had refused positive airway pressure therapy, revealed both percentage of rapid eye movement (REM) sleep (mean ± standard deviation [SD]: 19.88% ± 10.11%; range 1.94% to 35.01%) and REM sleep duration (minutes) (mean ± SD: 73.08 ± 48.24; range 3.49– 151.59) varied markedly over the 10 HSATs. Both percentage of REM sleep and REM sleep duration correlated negatively with sleep onset latency (r = −.661, P = .037 and r = −.748, P = .013, respectively) and the mean pulse rate during sleep (r = −.667, P = .035 and r = −.771, P = .009, respectively), and positively with sleep efficiency (r = .824, P = .003 and r = .922, P < .001, respectively) and percentage of stage N3 sleep (r = .784, P = .007 and r = .734, P = .016, respectively), an index of parasympathetic tone during sleep. These empirical findings suggest a previously unreported inverse relation of REM sleep with sleep fragmentation and sympathetic activation.
Gupta MA. Rapid eye movement sleep percentage and duration in posttraumatic stress disorder vary dynamically and inversely with indices of sympathetic activation during sleep and sleep fragmentation. J Clin Sleep Med. 2019;15(5):785–789.