Electroencephalographic and autonomic alterations in subjects with frequent nightmares during pre-and post-REM periods.
Péter Simor, János Körmendi, Klára Horváth, Ferenc Gombos, Péter P Ujma, Róbert Bódizs
Brain and Cognition November 1, 2014 DOI: 10.1016/j.bandc.2014.08.004 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 40 |
| Population | 19 individuals with nightmare disorder and 21 healthy controls |
| Topics | Dreaming |
| Keywords | Alpha power EEG Heart rate variability Sleep |
| Key findings | Nightmare disorder subjects exhibited increased alpha power during pre-REM periods and lacked the normal increase in heart rate variability before REM, indicating compromised sleep during NREM-REM transitions. |
Abstract
Abnormal arousal processes, sympathetic influences, as well as wake-like alpha activity during sleep were reported as pathophysiological features of Nightmare Disorder. We hypothesized that in Nightmare Disorder, wake-like cortical activity and peripheral measures linked to arousals would be triggered by physiological processes related to the initiation of REM periods. Therefore, we examined electroencephalographic (EEG), motor and autonomous (cardiac) activity in a group of nightmare (NM) and healthy control (CTL) subjects during sleep-state-transitions while controlling for the confounding effects of trait anxiety. Based on the second-nights' polysomnographic recordings of 19 Nightmare Disordered (NM) and 21 control (CTL) subjects, we examined the absolute power spectra focusing on the alpha range, measures of heart rate variability (HRV) and motor (muscle tone) activity during pre-REM and post-REM periods, separately. According to our results, the NM group exhibited increased alpha power during pre-REM, but not in post-REM, or stable, non-transitory periods. While CTL subjects showed increased HRV during pre-REM periods in contrast to post-REM ones, NM subjects did not exhibit such sleep state-specific differences in HRV, but showed more stable values across the examined sleep stages and less overall variability reflecting generally attenuated parasympathetic activity during sleep-state-transitions and during stable, non-transitory NREM states. These differences were not mediated by waking levels of trait anxiety. Moreover, in both groups, significant differences emerged regarding cortical and motor (muscle tone) activity between pre-REM and post-REM conditions, reflecting the heterogeneity of NREM sleep. Our findings indicate that NM subjects' sleep is compromised during NREM-REM transitions, but relatively stabilized after REM periods. The coexistence of sleep-like and wake-like cortical activity in NM subjects seems to be triggered by REM/WAKE promoting neural activity. We propose that increased arousal-related phenomena in NREM-REM transitions might reflect altered emotional processing in NM subjects.
Comparable studies
Other observational and cohort studies on dreaming, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Lucid Dreaming: a State of Consciousness with Features of Both Waking and Non-Lucid Dreaming Student volunteers trained to become lucid and signal lucidity with horizontal eye... | 2009 | Observational study | n = 6 |
| Nightmare Prevalence, Nightmare Distress, and Self-Reported Psychological Disturbance Young adults with a mean age of 20 years | 2002 | Prospective observational study | n = 116 |
| Long-term effects of extreme situational stress on sleep and dreaming Survivors of traumatic events who complained of sleep disturbances, compared with... | 1987 | Case-control study | n = 11 |
| The relationship of nightmare frequency and nightmare distress to well‐being Adults who reported dreams | 2004 | Observational cohort | n = 147 |
| Dreaming in NREM Sleep: A High-Density EEG Study of Slow Waves and Spindles Healthy human subjects | 2018 | Observational cohort | n = 14 |
Citations in the library
Cited by 18
- Nightmare Disorder and Isolated Sleep Paralysis Neurotherapeutics November 23, 2020
- Increased Reward-Related Behaviors during Sleep and Wakefulness in Sleepwalking and Idiopathic Nightmares PLoS One August 19, 2015
- Out-of-body experiences in relation to lucid dreaming and sleep paralysis: A theoretical review and conceptual model. Neuroscience & Biobehavioral Reviews August 1, 2024
- Altered parasympathetic activity during sleep and emotionally arousing wakefulness in frequent nightmare recallers European Archives of Psychiatry and Clinical Neuroscience March 2, 2023
- Local Neuronal Synchronization in Frequent Nightmare Recallers and Healthy Controls: A Resting-State Functional Magnetic Resonance Imaging Study Frontiers in Neuroscience March 18, 2021
and 13 more in the library
Cites 19
- Lucid Dreaming: a State of Consciousness with Features of Both Waking and Non-Lucid Dreaming Sleep September 1, 2009
- Prevalence of Nightmare Disorder in Psychiatric Outpatients Psychotherapy and Psychosomatics 2013
- State Dissociation, Human Behavior, and Consciousness Current Topics in Medicinal Chemistry September 1, 2011
- Lucid, Prelucid, and Nonlucid Dreams Related to the Amount of EEG Alpha Activity during REM Sleep Psychophysiology July 1, 1984
- Nightmare frequency in patients with primary insomnia heiDOK (Heidelberg University) 2009
and 14 more in the library