Parasomnia
from https://bpac.org.nz/bpj/2012/november/parasomnias.aspx
Definition & Classification
- Parasomnias = abnormal behaviours, perceptions, emotions, or movements during:
- Sleep onset
- Sleep
- Transitions between sleep stages
- Awakening
- Classification:
- Non-REM parasomnias (first third of night):
- Somnambulism (sleepwalking)
- Confusional arousals
- Sleep terrors
- Bruxism
- Sleep talking (may also occur in REM)
- REM parasomnias (later night):
- Nightmares
- REM sleep behaviour disorder (RBD)
- Recurrent sleep paralysis
- Non-REM parasomnias (first third of night):
📊 Epidemiology & Natural History
- 88% of children have at least one parasomnia by age 6.
- Onset often in childhood, may persist into adulthood.
- Decline in frequency after age 25.
- Often familial (e.g. somnambulism linked to HLA DQB1 gene).
- Most are benign and resolve spontaneously.
🧾 General Management Principles in General Practice
1. 🔍 Identify and Exclude Underlying Causes
- Medication-induced:
- Sedative hypnotics (e.g. zopiclone)
- SSRIs, TCAs, beta-blockers
- Antihistamines
- Substance-related:
- Caffeine, alcohol, nicotine, recreational drugs
- Psychiatric comorbidities:
- Anxiety, depression, PTSD
- Other sleep disorders:
- Obstructive sleep apnoea (OSA)
- Restless legs syndrome
- Narcolepsy
- Neurological conditions:
- Dementia, especially in elderly (RBD)
- Epilepsy (frontal lobe seizures mimicking parasomnias)
2. 💬 Reassurance & Education
- Common, especially in childhood.
- Often self-limiting.
- Most cases do not indicate significant psychopathology.
- Waking the person during an episode is not recommended—can worsen agitation or provoke violence.
- Carers should:
- Gently redirect the person to bed if possible.
- Avoid confrontation during episodes.
3. 🛌 Sleep Hygiene Measures
- Consistent sleep-wake schedule, including weekends.
- Avoid naps after 2pm.
- Avoid screens and bright lights before bedtime.
- Avoid alcohol, caffeine, nicotine—especially in evening.
- Reserve bed for sleep and intimacy only.
- Regular physical activity (preferably mid-late afternoon).
- Pre-bed routine: warm milk, calming activity, avoid stimulating tasks.
- If sleep-onset delayed >20 min: get out of bed, do quiet activity, return when sleepy.
4. 🏠 Environmental Safety Measures
- Remove obstacles, sharp objects, furniture near bed.
- Secure windows, especially in multistorey homes.
- Lock doors/exits if risk of wandering.
- Remove weapons or hazardous items (e.g. kitchen knives).
- Consider mattress on floor if risk of falling.
5. ⏰ Scheduled Waking (Non-REM Parasomnias)
- Useful for predictable episodes (e.g. sleepwalking, terrors).
- Wake patient 15–30 min before typical event time.
- Keep awake briefly, then allow return to sleep.
- Continue for 1–4 weeks; trial without afterwards.
💊 Pharmacological Management (Adults Only)
- Reserved for:
- Frequent/severe episodes.
- Risk to patient/others.
- Failure of non-pharmacological measures.
| Drug Class | Example & Dose | Indications/Notes |
|---|---|---|
| Benzodiazepines | Clonazepam 0.5–1 mg nocte, titrate as needed | First-line; effective for RBD, somnambulism. Caution: falls risk in elderly. |
| TCAs | Amitriptyline/Nortriptyline 10 mg nocte, titrate | Alternative if benzodiazepines not tolerated. Useful in sleep paralysis or nightmares. |
| Melatonin | 2–12 mg several hours before sleep | First-line alternative in RBD, esp. elderly. Safer than benzos. Not PBS-subsidised in Australia. Start 2–3 mg. |
⚠️ Avoid pharmacological treatment in children unless under paediatric/sleep specialist supervision.
🧠 Psychological Therapies
- Cognitive behavioural therapy (CBT): useful in nightmares, anxiety-related parasomnias.
- Relaxation techniques: prior to bed for stress-related triggers.
- Imagery Rehearsal Therapy: for trauma-related nightmares.
- Referral to psychologist or sleep physician as needed.
📋 Condition-Specific Notes
Non-REM Parasomnias
1. Somnambulism (Sleepwalking)
- Prevalence: 17% in children, 1–4% in adults.
- Episodes: semi-purposeful, often responsive to redirection.
- May involve dangerous behaviours (e.g. driving, cooking).
- Treatment: Trigger elimination, sleep hygiene, scheduled waking, clonazepam or TCAs if severe.
2. Confusional Arousals
- Brief partial awakenings with confusion, disorientation.
- May involve aggression, inappropriate behaviours.
- More common in children; in adults may signal psychiatric disorder.
- Treatment: Address underlying cause, reassure, sleep hygiene.
3. Sleep Terrors
- Sudden arousals with intense fear, tachycardia, screaming.
- Common in children, usually self-limiting.
- Treatment: Avoid triggers (fever, stress, fatigue), scheduled waking, reassurance.
4. Bruxism
- Involuntary jaw clenching/grinding.
- Associated with dental damage, jaw pain.
- Treatment: Dental referral if significant. Stress reduction. Occlusal splints for adults (not children). No role for meds.
5. Sleep Talking (Somniloquy)
- Vocalisations during sleep; benign and common.
- Treatment: None needed unless disruptive; stress management.
REM Parasomnias
1. Nightmares
- Vivid, distressing dreams with full recall.
- No confusion on waking; may impair daytime function.
- Treatment: CBT, desensitisation, imagery rehearsal therapy. Refer if PTSD suspected.
2. REM Sleep Behaviour Disorder (RBD)
- Dream-enactment behaviours due to loss of REM atonia.
- Risk of injury to self/others.
- Common in older men, Parkinson’s disease, Lewy body dementia.
- Treatment: Clonazepam or melatonin. Sleep study for diagnosis. Ensure safe sleep environment.
3. Recurrent Sleep Paralysis
- Transient muscle paralysis with fear, hallucinations at sleep-wake transitions.
- Associated with narcolepsy, anxiety, OSA.
- Treatment: Sleep hygiene, manage underlying cause, consider TCAs if severe.
⚠️ Red Flags: Consider Alternative Diagnoses
Nocturnal Frontal Lobe Epilepsy
- May mimic parasomnia:
- Brief (<30 sec) stereotyped episodes.
- Dystonic/dyskinetic movements.
- Tongue biting, urinary incontinence suggest seizure.
- Refer for EEG/sleep study if suspected.
📤 When to Refer
- Diagnostic uncertainty (e.g. epilepsy vs parasomnia).
- High injury risk.
- Atypical presentation.
- Lack of response to initial management.
- Child with persistent or severe episodes.
- Adult with RBD (rule out underlying neurodegeneration).
A Diagnosis Not to Be Missed: Nocturnal Frontal Lobe Epilepsy (NFLE)
- NFLE can closely mimic parasomnias, making it a critical differential diagnosis not to be missed.
Nocturnal Frontal Lobe Epilepsy (NFLE)
- Onset: Typically between 9–20 years.
- Episode Characteristics:
- Short duration (<30 seconds).
- Repetitive, stereotyped behaviours.
- Asymmetric, abnormal motor activity:
- Dystonic or dyskinetic postures.
- Grimacing, vocalisations.
- Rare features (but highly suggestive):
- Tongue biting.
- Urinary incontinence.
- High recurrence, including multiple episodes per night.
Parasomnias
- Onset: Typically in early childhood.
- History: Often a background of childhood parasomnias persisting into adulthood.
- Episode Characteristics:
- Longer duration.
- Less stereotyped, more variable movements.
- Rarely recur within the same night (except REM behaviour disorder).
- Course:
- Tends to decrease or cease after puberty.
| Non-REM Parasomnia | REM Parasomnia | Frontal Lobe Seizures | |
| Usual age at onset | Childhood | Older adults | Any age, most often between age 9 – 20 years |
| Gender bias | None | More common in males | May be more common in males |
| Occurrence during the night | First third | At least 90 minutes after sleep onset | Most frequently between 2 am and waking |
| Episodes per night | Usually one | One to several | Several |
| Episode duration | 1-30 minutes | 1-2 minutes | Seconds to one minute |
| Episode frequency | Sporadic | Sporadic | Almost nightly |
| Episode amnesia | Often total | Occasionally total | No amnesia |
| Stereotyped movement | Absent | Absent | Present |
| Autonomic activity | Present | Absent | Present |
| Evolution | Tend to disappear | Rare remission | May increase in frequency |
ACKNOWLEDGEMENT: Thank you to Dr Alex Bartle, Sleep Physician, Director Sleep Well Clinics, New Zealand for expert guidance in developing this article.