What is Parasomnia?
Parasomnia describes unusual behaviors that occur during sleep. Because events can occur during certain sleep stages, parasomnias are often classified according to that stage of sleep. Examples include NREM (non-REM) parasomnias which typically occur during deep sleep, REM parasomnias which are most associated with the dream stage of sleep, and something called “amnestic events,” which technically occur while the brain is awake but with limited or altered awareness.
NREM, REM and Amnestic Events
NREM sleep consists of light sleep, intermediate sleep, and deep sleep. During early childhood, the brain is “learning” how to transition from one stage of sleep to another, but these transitions can initially be abrupt. Therefore, it is not uncommon to observe NREM parasomnia behaviors such as sleep terrors or enuresis (bed wetting) during these early formative years. As we age, parasomnia events become less common. The diagnostic challenge is to figure out whether these events are occurring because (1) somewhere along the line, your sleep never organized correctly – in which case treatment addresses sleep organization directly; versus (2) whether something came along to cause the disruption – such as other sleep disorders like sleep apnea – in which case treatment is targeted towards preventing that disruption. Symptoms of NREM parasomnia include:
- Night Terrors
- Enuresis (wetting the bed)
REM sleep is typically associated with dreaming. Dreams are generally not pleasant, often disturbing, and sometimes violent. In order to “protect” ourselves from these dreams, the brain partially paralyzes the body from the neck down to prevent behaviors from occurring while we dream. For example, if we dream of running away from a criminal, we should not actually run in real time. REM parasomnia events occur when that paralysis switch is “broken”, so we act out the dreams. Symptoms of REM parasomnia include:
- Cursing during sleep
- Punching/kicking during sleep
- Other complex behaviors such as wrestling, jumping out of bed, running
Amnestic events occur while the brain is awake. However, awareness is often limited during these events. Some examples may include:
- Sleep talking, usually non-specific or mumbling
- Automatic behaviors like locking doors or getting dressed
- Eating during sleep
- Other complex behaviors including food preparation, driving, and cleaning
Normally, the sleep process involves transitions from wakefulness to light sleep to intermediate sleep to deep sleep to REM sleep, and then backwards – slowly, in a very organized way. Parasomnia disorders occur when there is a disruption of these transitions, with abrupt awakenings during the deep sleep stage (for NREM parasomnias) or during dream sleep (for REM parasomnias).
The best way to evaluate for these disorders is a sleep study in the laboratory setting. An in-lab sleep study, or polysomnography study, utilizes multiple electrodes over your scalp, face, and body. These electrodes gather data on sleep architecture (sleep stages) as well as breathing and limb movements. For NREM parasomnias, there may be abrupt transitions between deep sleep and other stages of sleep. For REM parasomnias, there are disruptions of the paralysis (or atonia) during REM sleep. Behaviors do not have to occur in the lab to diagnose these disorders.
Parasomnia Treatment Options
Treatment for parasomnia disorder is usually a combination approach. First and foremost, avoid potential triggers such as alcohol, substances, and sleep deprivation. Evaluate for underlying sleep disorders such as sleep apnea, medical conditions, and even certain medications. Depending on the parasomnia disorder, medications may be necessary but sleep physicians may also consider supplementing with certain herbal medications when appropriate. Finally, evaluation with other specialists may be needed depending on the specific parasomnia disorder.