Parasomnias: Causes, Types, Symptoms, Diagnosis, and Treatment

Parasomnias are a group of sleep disorders characterized by abnormal behaviours, movements, emotions, perceptions, or dreams that occur during sleep or sleep–wake transitions. These events can range from mild and harmless to potentially dangerous, affecting sleep quality and overall health.

Parasomnias are more common in children, but many forms persist into adulthood or appear later in life. Understanding the different types, their causes, and when to seek medical help is crucial for early diagnosis and effective management.

What Are Parasomnias?

They are undesirable physical events or experiences that occur while falling asleep, during sleep, or when waking up. Unlike insomnia, which involves difficulty sleeping, parasomnias occur during sleep itself, often without the individual being fully aware.

They are broadly classified based on the stage of sleep during which they occur:

• Non-REM parasomnias

• REM parasomnias

Sleep Stages and Parasomnias

Normal sleep consists of:

• Non-REM sleep (Stages N1, N2, N3)

• REM (Rapid Eye Movement) sleep

Each parasomnia is linked to disruptions in specific sleep stages, leading to abnormal behaviours.

Types of Parasomnias

Non-REM

These occur during deep sleep (N3 stage), usually in the first third of the night. The person is partially asleep and partially awake.

1. Sleep Terrors (Night Terrors)

Sleep terrors involve:

• Sudden screaming or crying

• Intense fear

• Rapid heart rate

• Sweating

• Difficulty being awakened

The individual usually has no memory of the event the next morning. Sleep terrors are most common in children aged 3–7 years.

2. Sleepwalking (Somnambulism)

Sleepwalking involves:

• Walking or performing activities while asleep

• Blank stare

• Poor responsiveness

• No recall of the event

Sleepwalking episodes may include simple behaviours (walking) or complex ones (leaving the house), making safety a concern.

3. Confusional Arousals

This condition presents as:

• Mental confusion on awakening

• Slurred speech

• Slow responses

• Irritability or agitation

Unlike sleep terrors, there is no intense fear, and episodes may last several minutes.

REM

These occur during REM sleep, usually in the second half of the night, when dreaming is more vivid.

4. Nightmare Disorder

Nightmares are:

• Frightening dreams

• Associated with full awakening

• Clearly remembered

Unlike sleep terrors, nightmares occur during REM sleep and are more common in adolescents and adults.

5. REM Sleep Behaviour Disorder (RBD)

RBD is characterized by:

• Acting out dreams

• Talking, shouting, punching, or kicking

• Risk of injury to self or bed partner

RBD is more common in older adults and may be associated with neurodegenerative conditions such as Parkinson’s disease.

6. Recurrent Isolated Sleep Paralysis

Sleep paralysis involves:

• Temporary inability to move or speak

• Occurs when falling asleep or waking up

• Awareness is intact

• May be accompanied by hallucinations

Episodes are usually brief but can be frightening.

Causes and Risk Factors of Parasomnias

They often result from a combination of genetic, neurological, psychological, and environmental factors.

Common Triggers Include:

• Sleep deprivation

• Irregular sleep schedules

• Stress and anxiety

• Fever (especially in children)

• Alcohol or substance use

• Certain medications (antidepressants, sedatives)

• Obstructive sleep apnea

• Neurological disorders

Who Is at Risk?

• Children: More prone to non-REM parasomnias

• Older adults: Higher risk of REM sleep behaviour disorder

• Individuals with mental health disorders

• People with disrupted sleep patterns

• Family history of parasomnias

Symptoms that should not be ignored

Seek medical evaluation if:

• Episodes occur frequently

• Behaviour becomes violent or dangerous

• Daytime sleepiness affects daily life

• Injuries occur during sleep

• Symptoms appear suddenly in adulthood

Diagnosis of Parasomnias

Diagnosis begins with a detailed sleep history, often involving input from a bed partner or caregiver.

Diagnostic Tools Include:

• Sleep questionnaires

• Sleep diaries

• Video recordings (home observations)

• Polysomnography (Sleep Study) – gold standard for complex or dangerous parasomnias

• Neurological evaluation when indicated

Treatment and management of Parasomnias

Treatment depends on the type, frequency, and severity of parasomnia.

General Management Strategies

• Maintaining a regular sleep schedule

• Ensuring adequate sleep duration

• Reducing stress

• Avoiding alcohol and sedatives

• Treating underlying sleep disorders

Safety Measures

• Locking doors and windows

• Removing sharp objects

• Padding furniture

• Sleeping on the ground floor if sleepwalking is severe

Medical Treatment

• Medications may be prescribed in selected cases:

  • Benzodiazepines

  • Melatonin

  • Antidepressants (for nightmares or RBD)

Behavioural Therapies

• Cognitive behavioural therapy (CBT)

• Imagery rehearsal therapy for nightmares

• Relaxation techniques

Parasomnias in Children vs Adults

When to Consult a Doctor

Medical consultation is advised if parasomnias:

• Interfere with quality of life

• Cause injury

• Begin in adulthood

• Are associated with neurological symptoms

Frequently Asked Questions (FAQs) on Parasomnias

1. Are they dangerous?

Most parasomnias are benign, but some can lead to injury, especially sleepwalking and REM sleep behaviour disorder.

2. Do they indicate a mental illness?

Not necessarily. While stress and anxiety may trigger episodes, parasomnias are primarily sleep-related neurological conditions.

3. Can they be cured?

Many childhood parasomnias resolve on their own. Adult parasomnias can often be effectively managed with treatment.

4. Is sleep paralysis harmful?

Sleep paralysis is not physically harmful but can be distressing. Recurrent episodes may require medical evaluation.

5. Can lifestyle changes reduce them?

Yes. Regular sleep, stress management, and avoiding alcohol can significantly reduce episodes.

6. Are they hereditary?

There is evidence of genetic predisposition, especially for sleepwalking and sleep terrors.

7. Do they require a sleep study?

Not always. A sleep study is recommended when:

• Diagnosis is unclear

• Behaviour is violent

• REM sleep behaviour disorder is suspected

8. Can children with parasomnias attend school normally?

Yes. Most children with parasomnias have normal daytime functioning.

9. Are they linked to neurological diseases?

Certain parasomnias, especially REM sleep behaviour disorder, may be associated with neurodegenerative conditions.

10. When should parasomnias be treated with medication?

Medication is reserved for frequent, severe, or dangerous episodes that do not respond to behavioural measures.

Parasomnias represent a diverse group of sleep disorders that can affect individuals of all ages. While many forms are harmless and self-limiting, others require careful evaluation and management. Early recognition, proper diagnosis, and individualized treatment can greatly improve sleep quality and safety.

If you or a loved one experiences unusual behaviours during sleep, consulting a healthcare professional or sleep specialist can provide clarity and peace of mind.

Sparsh Doctor List