Changes in dreaming induced by CPAP in severe obstructive sleep apnea syndrome patients

Abstract

SUMMARY To study dream content in patients with severe obstructive sleep apnea syndrome (OSAS) and its modification with Continuous Positive Airway Pressure (CPAP) therapy. We assessed twenty consecutive patients with severe OSAS and 17 healthy controls. Polysomnograms were recorded at baseline in patients and controls and during the CPAP titration night, 3 months after effective treatment and 2 years later in patients. Subjects were awakened 5-10 min after the beginning of the first and last rapid eye movement (REM) sleep periods and we measured percentage of dream recall, emotional content of the dream, word count, thematic units, sleep architecture and REM density. Dream recall in REM sleep was similar in patients at baseline and controls (51.5% versus 44.4% respectively; P ¼ .421), decreased to 20% and 24.3% the first and third month CPAP nights, and increased to 39% 2 years later (P ¼ 0.004). Violent/highly anxious dreams were only seen in patients at baseline. Word count was higher in patients than in controls. REM density was highest the first CPAP night. Severe OSAS patients recall dreams in REM sleep as often as controls, but their dreams have an increased emotional tone and are longer. Despite an increase in REM density, dream recall decreased the first months of CPAP and recovered 2 years later. Violent/ highly anxious dreams disappeared with treatment. A dream recall decrease with CPAP is associated with normalization of sleep in OSAS patients.

Predicting Dream Recall: EEG Activation During NREM Sleep or Shared Mechanisms with Wakefulness?

“…In keeping with the finding in apnea patients (Carrasco et al 2006), an increased SWS amount and a lower number of awakenings during the recovery night drastically affect DR frequency (De Gennaro et al 2010), suggesting that a "lighter" sleep facilitates the retrieving process of dreams. Similarly, a study carried out with a 40-h multiple nap protocol revealed that lower frontal delta and reduction of centro-parietal sigma activity during the last 15 min of NREM sleep is related to DR (Chellappa et al 2011).…”

“…In particular, insomnia patients recalled more dreams than healthy subjects (Schredl et al 1998) and the number of their nocturnal awakenings correlated with the number of dreams recalled (Charney et al 1977). Furthermore, a longitudinal investigation on patients with sleep apnea revealed a lower DR frequency in the first CPAP night, compared to the subsequent nights (Carrasco et al 2006). Therefore, a SWS rebound and a less fragmented sleep are related to a lower DR rate.…”

Dream recall frequency and nightmare frequency in patients with sleep-disordered breathing

“…On the one hand, no differences in dream recall following REM awakenings compared with healthy controls were reported by Groß [5] or Carrasco et al [2]. Similarly, Schredl et al [23] found a high recall rate (75%) for induced awakenings of patients with sleep apnea.…”

“…[21]). Second, sample sizes are often quite small in laboratory studies (N=33 [6], N=44 [23], N=20 [2]), so generalizations of nonsignificant findings are problematic due to insufficient statistical power. Within a larger sample of sleep apnea patients (N=238), Schredl [15] found that dream recall after a normal laboratory night without awakenings was lower compared with dream recall of healthy controls, with a small but significant correlation with the oxygen saturation nadir.…”

Parasomnias associated with sleep-disordered breathing and its therapy, including sexsomnia as a recently recognized parasomnia

“…Severe OSA can be associated with unpleasant dreams and nightmares, similar to RBD, which are controlled with nCPAP therapy [25]. In a controlled study involving 20 patients (19 males; mean age 51 years, range 34-66 years; mean AHI, 73.3 ± 25.3), although the frequency of dream recall was similar between OSA patients and controls, the OSA patients had significantly more emotional dreams and longer dreams, with aggressive and violent content.…”