Parasomnias

Parasomnias are undesirable physical, behavioral or experiential phenomena that occur during entry into sleep, within sleep, or during partial arousals from sleep. Depending on their exact manifestations, frequency and intensity, parasomnias can be considered normal sleep phenomena, especially when occurring during childhood, and may not significantly impact sleep quality or quantity, or daytime functioning. While some parasomnias (e.g., recurrent isolated sleep paralysis, sleep-related groaning) may cause relatively little enduring distress, others (e.g., nightmares, REM sleep behavior disorder, sleepwalking, sleep terrors) can have significant consequences, including marked psychological distress, self injuries and sleep disruption in the patient and a mixture of concern and apprehension in family members.

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations (visual and/or auditory), and, in some cases, cataplexy or the sudden loss of muscle control. The disorder usually begins during childhood or adolescence and affects approximately 0.04% of the general population. Narcolepsy with cataplexy (known as type 1) is caused by the loss of hypocretin-producing neurons. Hypocretin is a peptide that plays a key role in the regulation of wakefulness (sleep/wake cycles).

Although the diagnosis of narcolepsy with cataplexy is relatively straightforward, the diagnosis of narcolepsy without cataplexy (type 2) can be challenging. While there’s currently no cure for the disorder, treatments involving lifestyle adjustments and pharmacologic options can greatly improve symptoms.

There exist several online resources for people with the disorder, including the Narcolepsy Network and Wake up Narcolepsy.

Very likley. Sleep paralysis is the inability to move any voluntary muscle at when falling asleep or from awakening (e.g., from REM sleep) while being subjectively awake and conscious (eyes open and aware of one’s surroundings). Episodes, which can be exceedingly frightening, may last a few minutes and subside either spontaneously or when interrupted by noise or other external stimuli. Sleep paralysis is often accompanied by fear, hypnagogic hallucinations, and intense feelings of realism. One review article of over 36 500 people found a lifetime prevalence rate of approximately 7.5% for the general population, 28% for students, and 32% for psychiatric patients. Other studies, however, suggest considerably higher prevalence rates in the general adult population.

Sleep paralysis can be accompanied bya range of distressing experiences that may involve visual, auditory, or tactile imagery. One of the most common and frightening example is felt presence experiences (i.e., the distinct sensation that another sentient being, human or not, is present in the room). The felt presence is usually perceived as terrifyingly malevolent. Episodes of sleep paralysis have been described throughout history and across cultures, giving rise to a rich and varied depiction of the experience itself as well as of the nature of these evil forces and presences.

Techniques for disrupting sleep paralysis include moving the extremities and self-monitoring (raising awareness, promoting calm) and there is evidence to suggest that attempting small movements (e.g., trying to wiggle one’s toes or fingers, blinking, moving one's tongue) is considerably more effective than trying to move one’s arms, legs, torso, or trying to get up or to scream.

If you’d like to know more about the history of sleep paralysis, you can check out this recent article from The Atlantic, or this online entry.  Want more facts about sleep paralysis? You’ll find 7 of them here.