Parasomnias

Overview

Parasomnias are a group of sleep disorders that involve unusual behaviors, movements, emotions, perceptions, or experiences that happen while you’re falling asleep, sleeping, or waking up. They can range from mild and harmless, like talking in your sleep, to more disruptive or even dangerous behaviors, such as sleepwalking or acting out dreams. 

Parasomnias happen when the brain gets stuck between sleep and wakefulness. Instead of being fully asleep or fully awake, parts of the brain are in different states at the same time. This in-between state, in turn, can produce seemingly awake behaviors, although the person experiencing them is not fully conscious.

Generally, parasomnias are grouped by when they happen during sleep. They include:

Non-rapid eye movement (NREM) parasomnias: These parasomnias happen during non-rapid eye movement (NREM) sleep, the stage of sleep that happens more often during the first half of sleep. NREM parasomnias can include:

• Sleepwalking: During sleepwalking, a person gets up and walks around or performs activities while asleep. Although someone may appear awake, they’re difficult to wake up fully.
• Night terrors: Sudden episodes of screaming, fear, or intense agitation during sleep, with little to no memory of the event.
• Confusional arousals: This parasomnia is more common in children and includes waking in a confused or disoriented state, sometimes with slow speech or unusual behavior.
• Sleep-related eating disorder: This involves eating during partial awakenings at night, with little to no memory afterward.
• Sexsomnia: These sleep-related sexual behaviors happen unconsciously—they’re not intentional and not always a reflection of a person’s waking desires. While primarily considered an NREM parasomnia, these behaviors can also be observed during REM sleep, frequently as part of REM sleep behavior disorder (see below).

REM-related parasomnias: These parasomnias happen during rapid eye movement (REM) sleep, when the eyes rapidly move behind the eyelids and vivid dreaming occurs. This phase generally occurs during the second half of the night and includes: 

• Nightmare disorder: This involves frequent, distressing dreams that cause a person to wake up with a clear memory of the nightmare afterward, leading to significant emotional upset and sleep disruption.
• Sleep paralysis: This temporary inability to move when falling asleep or waking up can last anywhere from a few seconds to minutes and be accompanied by vivid hallucinations.
• REM sleep behavior disorder (RBD): In this parasomnia, a person physically acts out their dreams because the normal muscle paralysis of REM sleep is absent. For older adults, this disorder can be an early sign of some neurological diseases.

Other parasomnias: These parasomnias may not fit neatly into the non-REM or REM sleep phase and can happen when a person is falling asleep or waking up. They include:

• Sleep talking: Talking during sleep, also known as somniloquy. 
• Exploding head syndrome: This sensation involves hearing nonexistent, loud, explosive sounds during sleep transitions.
• Hypnopompic hallucinations: These vivid, dream-like sensory experiences feel incredibly lifelike when transitioning from sleep to wakefulness. 

What causes parasomnias?

Parasomnias can develop for different reasons—most often, a combination of biological, neurological, environmental, and lifestyle factors. Sometimes, there is no single clear cause. 

Some of the most common contributors to parasomnias include:

• Genetics: Genes can play a role in certain sleep disorders, such as sleepwalking or night terrors, suggesting that parasomnias can run in families. 
• Sleep deprivation: A lack of sleep can make the brain more likely to experience incomplete transitions between non-REM and REM sleep stages. 
• Stress and anxiety: In some people, the strain of stressful circumstances or emotional intensity can increase the likelihood of episodes.
• Irregular sleep schedules: Shift work, jet lag, or inconsistent bedtimes can disrupt normal sleep patterns, in turn affecting the stages of sleep.
• Medications or substances: Some medications or substances can increase the likelihood of parasomnias, such as antidepressants, sedatives, alcohol, or recreational drugs. 
• Fever or illness: Illness may trigger parasomnia episodes, especially in children, although they often resolve when the underlying illness has run its course.
• Neurological conditions: Parkinson’s disease, epilepsy, or brain injuries can be associated with REM sleep behavior disorder. This is because the brain circuits that control REM sleep muscle paralysis overlap with areas of the brain that are vulnerable in certain neurodegenerative diseases.
• Other sleep disorders: Other disorders, like obstructive sleep apnea and restless legs syndrome, can trigger or worsen parasomnia episodes.

Behavioral symptoms of parasomnias include: 

• Sleepwalking: Getting out of bed and walking, or performing routine activities while still asleep, is a commonly reported behavioral symptom, especially among children.
• Talking during sleep: Speaking, mumbling, or carrying on conversations without awareness can also occur.
• Automatic behaviors: These symptoms include performing routine tasks—like eating, dressing, or moving objects—without conscious control.
• Repetitive movements: Unusual movements such as rocking, thrashing, or jerking, or odd body positions or coordinated motions during sleep, may occur.
• Dream enactment: Physically acting out dreams via punching, kicking, or reaching can happen due to an absence of the typical muscle paralysis in REM sleep.
• Sexual behaviors during sleep: Unintentional sexual actions or advances while asleep are also a behavioral symptom of parasomnia.
• Temporary paralysis: A brief inability to move upon waking or falling asleep is a common experience. 

Perceptual symptoms of parasomnias include:

• Hallucinations: Seeing, hearing, or feeling things that are not actually there is common, especially during sleep-wake transitions. 
• Vivid dream recall: Remembering detailed, realistic dreams immediately after waking can also occur.
• Loud internal sounds: Hearing a sudden, explosive noise during sleep transitions can take place, disrupting sleep.

Cognitive symptoms of parasomnias include:

• Limited awareness: During a parasomnia episode, there’s often little or no understanding of what’s happening.
• Disorientation and delayed responsiveness: This looks like difficulty recognizing surroundings upon waking and slowed or incomplete responses to others. 
• Amnesia: This looks like a partial memory—or lack of any memory—of the event after the fact.

Emotional symptoms of parasomnias include:

• Fear or panic: People commonly report sudden screaming, crying, or visible terror during sleep.
• Agitation: During an event, restlessness or emotional distress can occur.
• Confusion: Appearing disoriented or mentally “foggy” when partially awakened.

Some symptoms of parasomnias, such as injuries from walking or moving during sleep, accidental injury to a bed partner, and dangerous behaviors like leaving the house or engaging in risky actions while asleep, can pose a serious risk of injury. 

All of these symptoms can affect overall rest and recovery in someone who experiences parasomnias. Disruptions to normal sleep patterns can leave you feeling unrefreshed, even after a normal amount of time in bed, and cause excessive daytime sleepiness. 

Parasomnias Diagnosis

Doctors diagnose parasomnias through a detailed look at your symptoms, including when they happen, how often they happen, and whether another medical issue may be involved. Sometimes symptoms alone are enough for a diagnosis. Still, in more complex cases, a sleep study will capture a more complete picture of what the brain and body are doing overnight.

Your doctor might use the following exams, tests, and imaging studies to diagnose parasomnias:

• Detailed physical and neurological exam: A conversation with a healthcare professional will help them understand what happens while you sleep, how often the episodes occur, the time of night they happen, if you remember them the next day, your general sleep habits, and ask questions about your family history. Next, a neurological exam will evaluate your reflexes, coordination, balance, and cognitive function to help identify signs of neurological disorders that may affect sleep regulation. 
• Input from family or bed partners: Since many people do not remember their episodes, outside observations are extremely valuable. A partner, parent, or roommate can help provide crucial details about your movements, sounds, emotional reactions, or unusual behaviors during sleep.
• Sleep diary and symptom logs: Your doctor might ask you to keep a daily log of sleep and wake times for at least one week, recording when you go to bed, when you fall asleep, when you wake, when you notice your symptoms (if at all), possible triggers, stress levels, medications or substances used, and any naps you take. This detailed tracking can help your provider spot patterns that support a parasomnia diagnosis.
• Overnight sleep study: Although not always required, a sleep study becomes important when the diagnosis is unclear or when dangerous behaviors are involved. In a sleep laboratory, sensors will be placed on your scalp, face, chest, and legs to monitor your brain waves, breathing, heart rate, oxygen levels, and body movements during sleep and identify abnormal sleep-stage transitions. A sleep study is often essential for REM sleep behavior disorder (RBD), as it can confirm the loss of normal muscle paralysis during REM sleep. An overnight sleep study can also rule out other disorders, like sleep apnea.
• Actigraphy: Actigraphy uses a watch-like device worn on the wrist to track your movements and light exposure. It also continuously records your sleep-wake activity for days or weeks to provide an objective view of your circadian rhythm. 
• Blood tests: Blood tests can rule out medical conditions that can cause metabolic issues, other disorders, or infections. Conversely, they can sometimes point to a diagnosis other than a parasomnia or sleep disorder.
• Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan: Your provider might order an MRI or CT scan if he or she suspects a neurological cause of your sleep symptoms.
• Electroencephalography (EEG): If your symptoms suggest another condition, your provider might order an EEG to evaluate brain activity for seizures. This procedure records electrical activity in the brain using electrodes placed on the scalp, then analyzes the data to detect abnormal patterns. 
• Additional testing: If your symptoms point toward a mental health disorder, a psychiatric evaluation may be recommended.

Because parasomnias can sometimes look like epilepsy, panic attacks, or psychiatric disorders, a careful and thorough evaluation is important.

Nonsurgical Treatments

As a baseline treatment, several lifestyle changes can reduce parasomnia episodes across multiple types. These include:

• Improving sleep hygiene: Maintaining a regular bedtime, limiting caffeine late in the day, and creating a calm sleep environment can help stabilize your sleep patterns and reduce episodes.
• Stress management: Because stress is a common trigger of parasomnias, relaxation techniques, mindfulness, and/or counseling can help decrease events.
• Avoiding sleep deprivation: A lack of sleep can worsen all types of parasomnias by increasing the likelihood of incomplete transitions between non-REM and REM sleep stages. Prioritizing and protecting adequate nighttime sleep through a consistent bedtime routine is crucial.
• Limiting alcohol and sedatives: Both alcohol and sedatives can disrupt sleep architecture and increase abnormal sleep behaviors, so avoiding them before bedtime may be recommended.
• Treating coexisting sleep disorders: If you or your loved one has another sleep disorder, like sleep apnea, restless legs syndrome, or narcolepsy, managing those conditions effectively can also reduce parasomnia episodes.

Psychological and supportive therapies can also play an essential role in parasomnia treatment. Cognitive behavioral therapy (CBT) can help treat a variety of mental health issues by reframing unhelpful thinking and behavior patterns, especially when anxiety, trauma, or unproductive thoughts worsen parasomnia symptoms. Support groups can also help normalize the parasomnia experience and provide ongoing support. 

Additionally, if you take medications that may contribute to parasomnia symptoms, your doctor might adjust or discontinue them. 

When parasomnia behaviors can lead to injury, such as in REM sleep behavior disorder (RBD), your doctor may add safety-focused interventions, such as: 

• Bedroom safety modifications: Lowering your mattress, locking doors and windows, padding hard-edged furniture, and removing sharp objects can reduce the risk of nighttime injury.
• Bed partner protection: In some cases, temporary separate sleeping arrangements may be necessary.

Surgical Treatments

Overall, surgery as a treatment for parasomnias is not common. However, when a separate medical problem is triggering parasomnia, surgery may be recommended to address the root cause. Indirect surgical approaches can include:

• Sleep apnea surgery: Procedures that improve breathing can reduce parasomnia episodes linked to sleep apnea. These can include a uvulopalatopharyngoplasty (UPPP), glossectomy, or a tonsillectomy with adenoidectomy.
• Neurosurgery: Although rare, if seizures or structural brain abnormalities are causing nighttime events, surgical procedures may be considered.