Differentials
Primary snoring
SIGNS / SYMPTOMS
Snoring, often intermittent and in association with nasal congestion, without diminished airflow through the upper airway. Still unclear at what point primary snoring begins to impact behaviour and cognition.[84]
INVESTIGATIONS
Polysomnography shows airflow through the upper airway unchanged or not diminished by >50% of baseline; no association of snoring with desaturations or arousals.
Central sleep apnoea
SIGNS / SYMPTOMS
Pauses in breathing lasting >20 seconds, or associated with arousal or desaturation without accompanied respiratory effort.
INVESTIGATIONS
Polysomnography shows discrete events of decrease in airflow 90% or more, lasting >20 seconds or associated with desaturation 3% or more, and/or arousal, which are not accompanied by respiratory effort.
Anxiety
SIGNS / SYMPTOMS
Refusal to sleep alone or in own bedroom because of underlying anxiety; can be confused with limit-setting behaviours in chronic insomnia disorder.
INVESTIGATIONS
No differentiating tests.
PTSD
SIGNS / SYMPTOMS
Refusal to sleep alone or in bedroom because of PTSD; can be confused with limit-setting behaviours in chronic insomnia disorder.
INVESTIGATIONS
No differentiating tests.
Restless legs syndrome
SIGNS / SYMPTOMS
Vague sensations of discomfort that get worse in the evening and at rest, and are alleviated with movement.
INVESTIGATIONS
Diagnosis is history-based. Polysomnography can show periodic limb movements, which are often found in association with the syndrome.[85]
Depression
SIGNS / SYMPTOMS
Depressed affect, early morning awakenings.
INVESTIGATIONS
No differentiating test.
Periodic limb movement disorder
SIGNS / SYMPTOMS
Repetitive, stereotypical limb movements often associated with wakening, not explained by other underlying medical issue.
INVESTIGATIONS
Polysomnography showing runs of at least four repetitive limb movements lasting 0.5 to 10 seconds occurring every 5 to 90 seconds.
Frontal lobe epilepsy
SIGNS / SYMPTOMS
Unusual movement and or vocalisation arising from sleep; often mistaken for confusional arousals or parasomnias.
INVESTIGATIONS
Polysomnography with video recording; full or extended electroencephalogram (EEG) montage. Abnormal EEG activity (spike/sharp/spike and wave discharge) associated with the activity in question.
Non-REM parasomnias
SIGNS / SYMPTOMS
Sleepwalking, sleep talking, and unusual activity of which the patient has no recollection in the morning. Often triggered by insufficient sleep, irregular schedule, inconsistent sleep environment, or fever.
INVESTIGATIONS
No differentiating test.
REM behaviour disorder
SIGNS / SYMPTOMS
Violent acting out of dreams; associated with narcolepsy and, in adults, with neurodegenerative disease.
INVESTIGATIONS
Polysomnography demonstrates correlation of violent behaviour with REM sleep.
Night terrors
SIGNS / SYMPTOMS
Episodes of screaming, yelling, incoherent moaning, diaphoresis, and visible anxiety lasting 10 to 20 minutes during which the child is inconsolable. There is no recollection of the event in the morning. Usually occur in the first half of the night.
INVESTIGATIONS
No differentiating test.
Nightmares
SIGNS / SYMPTOMS
Vivid, frightening dreams that wake the child and which the child remembers.
INVESTIGATIONS
No differentiating test.
Insufficient sleep
SIGNS / SYMPTOMS
Inadequate amount of time devoted to sleep.
INVESTIGATIONS
No differentiating test.
Jet lag-type circadian rhythm disorder
SIGNS / SYMPTOMS
Discoordinated sleepiness and wakefulness with external clock following travel across time zones; reflects dyssynchrony of external and circadian clocks.
INVESTIGATIONS
No differentiating test.
Advanced sleep phase disorder
SIGNS / SYMPTOMS
Tendency to become very sleepy in the early evening, and to arise early in the morning. Uncommon in children.
INVESTIGATIONS
No differentiating test.
Medication-induced abnormality
SIGNS / SYMPTOMS
Difficulty initiating, maintaining sleep; excessive daytime sleepiness, vivid dreams and nightmares, increased limb movements, symptoms of restless legs syndrome. Discontinuation of inciting drug may improve symptoms.
INVESTIGATIONS
No differentiating test.
Too much time in bed
SIGNS / SYMPTOMS
Difficulty initiating, maintaining sleep; child spending more time in bed than age-appropriate sleep requirements.
INVESTIGATIONS
No differentiating test.
Hypnic jerks
SIGNS / SYMPTOMS
Involuntary jerks of one or more muscle segments during wake-sleep transition.
INVESTIGATIONS
No differentiating test.
Autism
Primary nocturnal enuresis
SIGNS / SYMPTOMS
Primary nocturnal enuresis refers to intermittent bed wetting in a child who has never been dry. The child must be at least 5 years old to make the diagnosis.
Secondary nocturnal enuresis refers to intermittent bed wetting in a child who has previously been dry for at least 6 months.
INVESTIGATIONS
No differentiating test.
Colic
SIGNS / SYMPTOMS
Crying in evening in infants lasting 3 or more hours/day, for 3 or more days/week, for 3 or more weeks.[87]
INVESTIGATIONS
No differentiating test.
Food allergies
SIGNS / SYMPTOMS
Nocturnal awakenings secondary to discomfort.
INVESTIGATIONS
Elimination trial of specific food.
Ear infection
SIGNS / SYMPTOMS
Nocturnal awakenings secondary to ear discomfort.
Physical examination with finding of inflamed tympanic membrane.
INVESTIGATIONS
No tests usually needed.
Asthma
SIGNS / SYMPTOMS
Nocturnal awakenings secondary to breathing discomfort. Physical examination with findings of wheeze, prolonged expiratory phase.
INVESTIGATIONS
Spirometry showing reversible obstructive defect.
Post-traumatic hypersomnolence
SIGNS / SYMPTOMS
Excessive daytime sleepiness following head trauma.
INVESTIGATIONS
No differentiating test.
Smith-Magenis syndrome
SIGNS / SYMPTOMS
Disrupted sleep patterns, in setting of developmental delay; dysmorphic features. In the differential for difficulty initiating and maintaining sleep. Rare.
INVESTIGATIONS
Chromosome 17p microdeletion present, increased melatonin secretion during the day. Response to melatonin at night and beta-blockers during daytime.
Kleine-Levin syndrome
SIGNS / SYMPTOMS
Episodic hypersomnolence, hyperphagia, hypersexuality. In the differential for hypersomnolence. Rare.
INVESTIGATIONS
No differentiating test.
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