Somnambulism: Clinical aspects and pathophysiological hypotheses

Department of Psychology, Université de Montréal, Montreal, QC, Canada.
The Lancet Neurology (Impact Factor: 21.9). 03/2013; 12(3):285-94. DOI: 10.1016/S1474-4422(12)70322-8
Source: PubMed


Somnambulism, or sleepwalking, can give rise to a wide range of adverse consequences and is one of the leading causes of sleep-related injury. Accurate diagnosis is crucial for proper management and imperative in an ever-increasing number of medicolegal cases implicating sleep-related violence. Unfortunately, several widely held views of sleepwalking are characterised by key misconceptions, and some established diagnostic criteria are inconsistent with research findings. The traditional idea of somnambulism as a disorder of arousal might be too restrictive and a comprehensive view should include the idea of simultaneous interplay between states of sleep and wakefulness. Abnormal sleep physiology, state dissociation, and genetic factors might explain the pathophysiology of the disorder.

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Available from: Antonio Zadra, Jul 28, 2014
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    • "In contrast to the considerable research having focused on sleep-related parameters associated with sleepwalking (see Zadra et al., 2013 for a review), relatively little attention has been devoted to the potential consequences of sleepwalking on daytime functioning. A series of recent studies have highlighted the presence of excessive daytime sleepiness (EDS) in a significant proportion of sleepwalkers (Desautels "
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    ABSTRACT: Sleepwalkers often complain of excessive daytime somnolence. Although excessive daytime somnolence has been associated with cognitive impairment in several sleep disorders, very few data exist concerning sleepwalking. This study aimed to investigate daytime cognitive functioning in adults diagnosed with idiopathic sleepwalking. Fifteen sleepwalkers and 15 matched controls were administered the Continuous Performance Test and Stroop Colour-Word Test in the morning after an overnight polysomnographic assessment. Participants were tested a week later on the same neuropsychological battery, but after 25 h of sleep deprivation, a procedure known to precipitate sleepwalking episodes during subsequent recovery sleep. There were no significant differences between sleepwalkers and controls on any of the cognitive tests administered under normal waking conditions. Testing following sleep deprivation revealed significant impairment in sleepwalkers' executive functions related to inhibitory control, as they made more errors than controls on the Stroop Colour-Word Test and more commission errors on the Continuous Performance Test. Sleepwalkers' scores on measures of executive functions were not associated with self-reported sleepiness or indices of sleep fragmentation from baseline polysomnographic recordings. The results support the idea that sleepwalking involves daytime consequences and suggest that these may also include cognitive impairments in the form of disrupted inhibitory control following sleep deprivation. These disruptions may represent a daytime expression of sleepwalking's pathophysiological mechanisms. © 2015 European Sleep Research Society.
    Journal of Sleep Research 06/2015; DOI:10.1111/jsr.12315 · 3.35 Impact Factor
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    • "Taken together, these findings suggest that somnambulism could be due to a dysfunction in SWS regulation (see [2] for a review). Although a majority of polysomnographic (PSG) studies of sleepwalkers have examined general all-night sleep characteristics, increasing attention has been paid to the study of sleep EEG variables immediately preceding the onset of somnambulistic episodes. "
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    ABSTRACT: Objective: Recent studies have suggested that the onset of sleepwalking episodes may be preceded by fluctuations in slow-wave sleep electroencephalographic characteristics. However, whether or not such fluctuations are specific to sleepwalking episodes or generalized to all sleep–wake transitions in sleepwalkers remains unknown. The goal of this study was to compare spectral power for delta (1–4 Hz) and slow delta (0.5–1 Hz) as well as slow oscillation density before the onset somnambulistic episodes versus non-behavioral awakenings recorded from the same group of sleepwalkers. A secondary aim was to describe the time course of observed changes in slow-wave activity and slow oscillations during the 3 min immediately preceding the occurrence of somnambulistic episodes. Methods: Twelve adult sleepwalkers were investigated polysomnographically during the course of one night. Results: Slow-wave activity and slow oscillation density were significantly greater prior to patients' somnambulistic episodes as compared to non-behavioral awakenings. However, there was no evidence for a gradual increase over the 3 min preceding the episodes. Conclusions: Increased slow-wave activity and slow oscillation density appear to be specific to sleepwalking episodes rather than generalized to all sleep–wake transitions in sleepwalkers.
    Sleep Medicine 10/2014; 15(12). DOI:10.1016/j.sleep.2014.07.020 · 3.15 Impact Factor
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    • "The authors concluded that the dissociation between these two slowwave synchronization processes in time and (brain) space suggests that they could become pathologically disturbed with sleep disorders – including NREM sleep parasomnias that emerge from slow-wave sleep. Other promising future research areas that could lead to a deeper understanding of NREM sleep parasomnias include various brain imaging techniques (including SPECT, PET, transcranial magnetic stimulation), and familial, genetic, and molecular studies that should provide additional critical information on the neurobiological substrate of NREM sleep parasomnias [13]. "
    Sleep Science 09/2014; 26(3). DOI:10.1016/j.slsci.2014.11.006
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