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ICSD-2 Classification

V. Parasomnias

• Confusional Arousals

• Sleepwalking

• Sleep Terrors

• REM Sleep Behavior Disorder

• Recurrent Isolated Sleep Paralysis

• Nightmare Disorder

• Sleep Related Dissociative Disorder

• Sleep Related Groaning (Catathrenia)

• Exploding Head Syndrome

• Sleep Related Hallucinations

• Sleep Related Eating Disorder

Confusional arousals

• Diagnostic Criteria

– Recurrent confusion or confusional behavioral during an arousal or awakening

• Disorientation, slow speech, confusion

• Inappropriate behavior, may be violent or sexual

• Anterograde and retrograde amnesia

• Typically last 5-15 minutes but may last up to 40 minutes

• Precipitating factors include recovery from sleep deprivation, OSA, PLMD, psychotropic medications, drug abuse and forced awakenings

• PSG may show brief episodes of delta sleep, stage 1 sleep, microsleeps, diffuse alpha (but normal PSG does not rule out the dx)

Sleepwalking

• Diagnostic Criteria

– Ambulation during sleep

– Persistence of sleep, altered state of consciousness or impaired judgment during ambulation demonstrated by at least 1 of the following:

• Difficulty in arousing the person

• Mental confusion when awakened

• Amnesia for the episode

• Routine behaviors at inappropriate times

• Inappropriate or nonsensical behaviors

• Dangerous behaviors

• Up to 12% prevalence in childhood; 4% adults

• Sleepwalking can be considered an expected event in childhood

• Sleepwalking in adolescence or adulthood may require clinical attention

• Precipitating factors: sleep deprivation (most common), hyperthyroidism, migraines, head injury, encephalitis, stroke, OSA, travel, fever, stress, medications (lithium, phenothiazines, anticholinergics), fragmented sleep

• PSG:

– Hypersynchronous delta waves may be seen but are nonspecific (OSA)

– Post-arousal EEG may show delta activity mixed with other rhythms

– Multiple arousals from SWS without parasomnia activity supports dx

– Partial or complete parasomnia activity following arousal from SWS or stage 2 may be seen

– Helpful to identify precipitating factors of OSA, PLMS

– Useful to demonstrate normal muscle atonia during REM to rule out RBD

Sleep Terrors

• Diagnostic Criteria

– Sudden episode of terror occurs during sleep, usually initiated by a cry or loud scream accompanied by autonomic and behavioral manifestations of intense fear

– At least 1 of the following:

• Difficulty in arousing the person

• Mental confusion when awakened

• Amnesia for the episode

• Dangerous behaviors

• 1-6.5% children; 2.2% adults

• Usually occurs age 4-12 and resolves spontaneously during adolescence

• Same precipitating factors as sleepwalking

• PSG is not required for diagnosis

– Helpful to rule out precipitating causes

– May see arousals out of SWS (similar findings to sleepwalking)

Rem Sleep Behavior Disorder (RBD)

Diagnostic Criteria

• Presence of REM sleep without atonia:

– EMG with excessive amounts of sustained or intermittent elevation of submental EMG tone

– or excessive phasic submental or limb EMG twitching

• At least 1 of the following:

– Sleep related injurious, potentially injurious or disruptive behavior by history

– Abnormal REM sleep behaviors documented during PSG

• Absence of EEG epileptiform activity unless RBD activity can be clearly distinguished from any concurrent REM sleep related seizure disorder

• RBD is strongly associated with Neurodegenerative disorders (Parkinson's, Dementia with Lewy bodies, multi-system atrophy)

– 1/3 of Parkinson's and 90% MSA have RBD

• 13% of patients with RBD have narcolepsy

• Acts out dreams (typically violent)

• Isomorphism: pt awakens, recalls dreams which corresponds to actions during sleep

• Typical behaviors include talking, laughing, shouting, swearing, reaching, flailing, punching, kicking, sitting up, crawling, running

• Walking is quite uncommon

• Eyes stay closed during events

• Chewing, eating, drinking, sexual behaviors, urination and defecation have NOT been reported with RBD

	Sleepwalking	RBD	Seizures
Walking	Obviously	uncommon
Eyes	Open, blank stare	closed
Timing	1st third of night	Latter half of night
Sleep stage	SWS	REM
PSG	Normal or Arousals from SWS	Increased EMG tone during REM	Seizure activity

Recurrent Isolated Sleep Paralysis

• Diagnostic Criteria

– Inability to move the trunk and all limbs at sleep onset or awakening

– Episodes last seconds to minutes

• Pt does not have narcolepsy

• Breathing typically is unimpaired

• Consciousness and recall are preserved

• Hallucinations common (25-75%)

• Worse with sleep deprivation, irregular sleep-wake schedule and stress

• 5-6% of population (but 15-40% young students report at least one episode of sleep paralysis)

Nightmare Disorder

• Diagnostic Criteria

– Recurrent episodes of awakening with recall of intensely disturbing mentation

– Full alertness on awakening without significant confusion

– At least 1 of the following

• Delayed return to sleep after episodes

• Occurrence during the latter half of the habitual sleep period

• 10-50% of children age 3-5 yrs have nightmares severe enough to disturb parents

• 50-85% adults report at least occasional nightmare

• Antidepressants, anti-hypertensives and dopamine agonists can cause nightmares

• Nightmares that occur intermittently with ASD or PTSD are expected; if they require independent clinical attention, then nightmare disorder should be coded.

	Night Terror	Nightmare Disorder
Timing	1st third of night	2nd half
Sleep Stage	NREM (SWS)	REM
Dream recall	Fragmented or none	Immediate and clear
Autonomic activity	Prominent	Minimal
Alertness	Confused	Alert

Sleep Related Dissociative Disorders

• Diagnostic Criteria

– Dissociative Disorder emerges in association with the major sleep period

– One of the following must be present:

• PSG demonstrates dissociative episode that emerges during sustained wakefulness either in transition from wakefulness to sleep or after an awakening

• History compatible with above

Sleep Related Groaning (Catathrenia)

• Diagnostic Criteria

– History of regularly occurring groaning or monotonous vocalization occurring during sleep OR

– PSG with respiratory sound monitoring reveals characteristic respiratory dysrythmia predominantly during REM sleep

• Only expiratory sound

Exploding Head Syndrome

• Diagnostic Criteria

– Pt complains of a sudden loud noise or explosion in the head at the wake-sleep transition or upon waking in the night

– The experience is NOT associated with significant pain complaints

– The patient arouses immediately after the event, usually with a sense of fright

• Felt to be a sensory variant of hypnic jerks (sleep starts)

• Benign course but if frequent may lead to insomnia

• Needs to be differentiated from headache syndromes (exploding head syndrome is not painful).

Sleep Related Hallucinations

• Diagnostic Criteria

– Hallucinations just prior to sleep onset, upon awakening, or in the morning

– Hallucinations are predominantly visual

• Hypnagogic hallucinations are reported in 25-37%

• Hypnopompic hallucinations 7-13%

• Complex nocturnal visual hallucinations appear to be a distinct variant that is less common

– Typically complex, vivid, immobile images of people or animals

– May last for several minutes and disappears when ambient light is increased

• Appear to be SOREMP related phenomenon but some studies indicate complex nocturnal visual hallucinations occur out of NREM

• Complex nocturnal visual hallucinations may be seen in narcolepsy, Parkinson's disease, dementia with Lewy bodies, visual loss, midbrain and diencephalon pathology, use of beta-blockers

• Anxiety disorders are noted in some patients.

Sleep Related Eating Disorder

Diagnostic Criteria

• Recurrent episodes of involuntary eating and drinking during the main sleep period

• One or more MUST be present:

– Consumption of peculiar forms or combinations of food or inedible or toxic substances

– Insomnia related to sleep disruption from repeated episodes of eating with EDS

– Sleep related injury

– Dangerous behaviors while seeking or preparing food

– Morning anorexia

– Adverse health effects from recurrent binge eating of high calorie foods

• Rates determined by self-administered questionnaire

– 16.7% inpatient eating disorders group

– 8.7% outpatient eating disorders group

– 4.6% unselected university student group

• Mostly females age 22-29

• Precipitating factors

– Preceded by sleepwalking in 50%

– OSA, PLMD, RLS, meds (zolpidem, triazolam, lithium, anticholinergics)

• Must be distinguished from Nocturnal Eating Syndrome

– Overeating between dinner and sleep

– eating during complete awakenings with recall

– absence of bizarre foods, toxic substances

Reference:

The International Classification of Sleep Disorders, Second Edition. The American Academy of Sleep Medicine Press, 2005. Can be purchased at the AASM store online!