Sleep respiratory concomitants of comorbid panic and nightmare complaint in post-traumatic stress disorder

Clinical neurophysiology of REM parasomnias: Diagnostic aspects and insights into pathophysiology

Parasomnias are due to a transient unstable state dissociation during entry into sleep, within sleep, or during arousal from sleep, and manifest with abnormal sleep related behaviors, perceptions, emotions, dreams, and autonomic nervous system activity. Rapid eye movement (REM) parasomnias include REM sleep behavior disorder (RBD), isolated recurrent sleep paralysis and nightmare disorder. Neurophysiology is key for diagnosing these disorders and provides insights into their pathophysiology. RBD is very well characterized from a neurophysiological point of view, also thank to the fact that polysomnography is needed for the diagnosis. Diagnostic criteria are provided by the American Academy of Sleep Medicine and video-polysomnography guidelines for the diagnosis by the International REM Sleep Behavior Disorder Study Group. Differences between the two sets of criteria are presented and discussed. Availability of polysomnography in RBD provides data on sleep electroencephalography (EEG), electrooculography (EOG) and electromyography (EMG). Sleep EEG in RBD shows e.g. changes in delta and theta power, in sleep spindles and K complexes. EMG during REM sleep is essential for RBD diagnosis and is an important neurodegeneration biomarker. RBD patients present alterations also in wake EEG, autonomic function, evoked potentials, and transcranial magnetic stimulation. Clinical neurophysiological data on recurrent isolated sleep paralysis and nightmare disorder are scant. The few available data provide insights into the pathophysiology of these disorders, demonstrating a state dissociation in recurrent isolated sleep paralysis and suggesting alterations in sleep macro- and microstructure as well as autonomic changes in nightmare disorder.

Trauma Associated Sleep Disorder: Clinical Developments 5 Years After Discovery

PURPOSE OF REVIEW

We review recent and growing evidence that provides support for a novel parasomnia, trauma associated sleep disorder (TASD). Based on these findings, we further develop the clinical and polysomnographic (PSG) characteristics of TASD. We also address factors that precipitate TASD, develop a differential diagnosis, discuss therapy, and propose future directions for research.

RECENT FINDINGS

Nightmares, classically a REM phenomenon, are prevalent and underreported, even in individuals with trauma exposure. When specifically queried, trauma-related nightmares (TRN) are frequently associated with disruptive nocturnal behaviors (DNB), consistent with TASD. Capture of DNB in the lab is rare but ambulatory monitoring reveals dynamic autonomic concomitants associated with disturbed dreaming. TRN may be reported in NREM as well as REM sleep, though associated respiratory events may confound this finding. Further, dream content is more distressing in REM. Therapy for this complex disorder likely requires addressing not only the specific TASD components of TRN and DNB but comorbid sleep disorders. TASD is a unique parasomnia developing after trauma. Trauma-exposed individuals should be specifically asked about their sleep and if they have nightmares with or without DNB. Patients who report TRN warrant in-lab PSG as part of their evaluation.

Sleep disturbances in veterans with chronic war-induced PTSD

Post-traumatic stress disorder is related to a wide range of medical problems, with a majority of neurological, psychological, cardiovascular, respiratory, gastrointestinal disorders, diabetes, as well as sleep disorders. Although the majority of studies reveal the association between PTSD and sleep disturbances, there are few studies on the assessment of sleep disruption among veterans with PTSD. In this review, we attempt to study the sleep disorders including insomnia, nightmare, sleep-related breathing disorders, sleep-related movement disorders and parasomnias among veterans with chronic war-induced PTSD. It is an important area for further research among veterans with PTSD.

Dreaming in posttraumatic stress disorder: A critical review of phenomenology, psychophysiology and treatment

This review summarizes the available knowledge on the phenomenology of posttraumatic dreams. Posttraumatic nightmares are reported by up to 70% of individuals suffering from posttraumatic stress disorder (PTSD). An extensive review of polysomnographic studies suggests that neither this high incidence nor the occurrence of posttraumatic nightmares throughout the sleep cycle can be explained by altered REM sleep parameters. The assumption that a reduction of dream recall may serve as a coping mechanism in PTSD patients is questionable. About 50% of posttraumatic dreams comprise exact replications of the traumatic events. Therefore dreams in PTSD do not have stereotypical content. Data characterizing non-replicative posttraumatic dreams and indicating a change in dream content over time must be considered preliminary. Occurrence of posttraumatic dreams is associated with psychopathological developments. Imagery Rehearsal Therapy has repeatedly been proven to be a valuable tool in treating patients suffering from posttraumatic dream disturbance. A deeper knowledge of posttraumatic dreams is essential for any theory of PTSD as well as for a better understanding of the overall function of dreaming.

The effect of psychosocial stress on sleep: a review of polysomnographic evidence

This systematic review examines the effect of diverse psychosocial stressors on polysomnographic measures of sleep. Sixty-three articles were located and categorized in terms of the types of stressors imposed. Experimental stress resulted in fairly consistent changes: decreases in slow wave sleep, REM sleep, and sleep efficiency (SE), as well as increases in awakenings. Data were limited in terms of response to non-experimental stressors, except for the case of post-traumatic stress disorder (PTSD) on sleep, where a number of reports suggest that PTSD patients have increased awakenings and decreased SE. Future research needs to define stress more precisely in terms of duration and severity and to measure its impacts on sleep in populations that differ in terms of age, comorbid illness, gender, and so forth. Without such fine-grained analyses, it is difficult to draw definitive conclusions about this important area.

Sleep in post-traumatic stress disorder and panic: convergence and divergence

Disturbed sleep is a common clinical problem in anxiety disorders, particularly in patients with post-traumatic stress disorder (PTSD) and panic disorder (PD). Several studies have attempted to validate the subjective sleep complaints of these disorders using laboratory polysomnography. These attempts, typically focusing on PTSD or PD independently, have demonstrated inconsistent results. To our knowledge, no such studies have attempted to directly compare and contrast sleep disturbances in PTSD and PD together. Our review of the studies of subjective sleep disturbances, sleep architecture, and sleep-related biologic phenomena suggests that a comparative characterization of sleep disturbances in these two disorders is timely. Such an inference is based on our identification of several areas of convergence and divergence between PTSD and PD found in the published literature, as well as our own preliminary investigations. Specifically, PTSD and PD seem to converge on several sleep-related parameters, namely, sleep quality, presence of episodic parasomnias, and movement time. They also appear to diverge in other important sleep-related areas such as respiratory disturbances and the particular phenomenological nature of episodic parasomnias, namely nightmares or nocturnal panic attacks. Investigations focusing on such overlapping phenomena may provide groundwork for further elucidation of central fear systems underlying these two disorders. Additionally, such sleep studies have the potential to provide important insights into ongoing efforts to develop a cohesive conceptual framework into the patho-physiologies of these disorders.