medRxiv
February 17, 2026
Constantin Weberpals, A. Specht, Natasja Bonde Andersen et al.
preprint
Abstract Type 1 narcolepsy (NT1), a disorder caused by the loss of hypocretin/orexin transmission, is characterized by daytime sleepiness and symptoms where Rapid Eye Movement (REM) sleep, a state normally occurring from middle to late in the night, can intermingle with wakefulness. This results in cataplexy and sleep paralysis, episodes of muscle paralysis when awake, or in the generation of...
Journal of Sleep Research
October 1, 2025
Claudia Picard-Deland, Matteo Cesari, Ambra Stefani et al.
Parasomnias are abnormal behaviours or mental experiences during sleep or the sleep-wake transition. As disorders of arousal (DOA) or REM sleep behaviour disorder (RBD) can be difficult to capture in the sleep laboratory and may need to be diagnosed in large communities, new home diagnostic devices are being developed, including actigraphy, EEG headbands, as well as 2D infrared and 3D time of...
Sleep Medicine
January 2, 2025
F Provini, Birgit Högl, Alex Iranzo et al.
According to the ICSD-3TR, nightmare disorder is characterized by extended, extremely dysphoric, and well-remembered dreams that usually involve threats to survival, security, or physical integrity. The dream experience causes clinically significant distress or impairment in social, occupational, or other important areas of functioning. Nightmare disorder occurs in 2–6% of adults. Nightmares...
Clinical Neurophysiology Practice
2024
M. Bergmann, Birgit Högl, Ambra Stefani
Highlights • RBD presents REM sleep without atonia, EEG slowing, impaired functional connectivity, microstructural sleep EEG changes, among others.• During sleep paralysis there is a REM-wake dissociation - an intermediate state between REM and wakefulness, REM sleep or EEG alpha frequencies.• Nightmare disorder shows reduced sleep, increased awakenings, reduced SWS, increased respiratory and...
Neurotherapeutics
November 23, 2020
Ambra Stefani, Birgit Högl
65 citations
Nightmare disorder and recurrent isolated sleep paralysis are rapid eye movement (REM) parasomnias that cause significant distress to those who suffer from them. Nightmare disorder can cause insomnia due to fear of falling asleep through dread of nightmare occurrence. Hyperarousal and impaired fear extinction are involved in nightmare generation, as well as brain areas involved in emotion...
Handbook of clinical neurology
2019
Ambra Stefani, Evi Holzknecht, Birgit Högl
Rapid eye movement (REM) sleep behavior disorder (RBD), sleep paralysis, and nightmare disorder are the three REM sleep parasomnias outlined by the International Classification of Sleep Disorders. In this review we address the clinical neurophysiology of these disorders. The majority of neurophysiologic studies have been conducted in RBD, and fewer studies have evaluated patients with nightmare...
Journal of Clinical Sleep Medicine
January 15, 2018
Franziska Di Pauli, Ambra Stefani, Evi Holzknecht et al.
Few studies have addressed dreaming in patients with sleep apnea. We hypothesized that respiratory events and subsequent oxygen desaturation act as an important physiological trigger and may thus influence dream content in patients with a sleep-related breathing disorder. Seventy-six patients (28 women, mean age 54 years, range 20-82) who underwent polysomnography because of suspected sleep...
CONTINUUM Lifelong Learning in Neurology
August 2017
Birgit Högl, Alex Iranzo
The most common rapid eye movement (REM) parasomnia encountered by neurologists is REM sleep behavior disorder (RBD), and nightmares are so frequent that every neurologist should be able to differentiate them from the dream enactment of RBD. Isolated sleep paralysis is relatively common and is often mistaken for other neurologic disorders. This article summarizes the current state of the art in...
Sleep Medicine
January 16, 2015
Katja Valli, Birgit Frauscher, Taina Peltomaa et al.
Objective: Rapid eye movement (REM) sleep behavior disorder (RBD) has been related to altered, action-filled, vivid, and aggressive dream content, but research comparing the possible differences in dreams of Parkinson's disease (PD) patients with and without RBD is scarce. The dream content of PD patients with and without RBD was analyzed with specific focus on action-filledness, vividness,...
Journal of Sleep Research
August 4, 2011
Katja Valli, Birgit Frauscher, Viola Gschliesser et al.
58 citations
Motor activity in rapid eye movement (REM) sleep behaviour disorder (RBD) has been linked to dream content. Systematic and controlled sleep laboratory studies directly assessing the relation between RBD behaviours and experienced dream content are, however, largely lacking. We aimed to investigate whether a link can be established between RBD behaviours and dream content when both are...