Differentials
Untreated sleep apnea
SIGNS / SYMPTOMS
Patients often snore, snort, gasp for air, or choke during sleep.
Features predisposing to sleep apnea, such as large neck circumference, high body mass index, crowded oropharynx, glossomegaly.
INVESTIGATIONS
Polysomnogram (PSG) plus positive airway pressure (PAP) titration.
PSG shows loud snoring, elevated arousal index, and an apnea-hypopnea index of ≥5.
PAP (continuous PAP or bilevel PAP) titration: a progressive increase in PAP level eliminates the apneas, hypopneas, and snoring; improves arousal index; and normalizes the oxygenation and/or flow contour.
Periodic limb movements of sleep
SIGNS / SYMPTOMS
Excessive daytime sleepiness in the absence of cataplexy, hypnagogic/hypnopompic hallucinations, and sleep paralysis.
INVESTIGATIONS
Polysomnogram usually shows periodic limb movement index >20.
Restless legs syndrome (RLS)
SIGNS / SYMPTOMS
Typical symptoms in adults and children >12 years old include an urge to move the legs. Usually accompanied or caused by uncomfortable sensations in the legs.[3]
Symptoms begin or worsen during periods of inactivity, are worse at night, and are partially or totally relieved by movement.
Children may present with a biologic parent with RLS.
INVESTIGATIONS
No need for polysomnogram, unless to exclude other conditions.
Distinguished by typical clinical presentation. Children may have a polysomnographic periodic leg movement index >5/hour of sleep.
Behaviorally induced insufficient sleep syndrome
SIGNS / SYMPTOMS
Sleep history: patients report getting better after oversleeping or catching up on sleep.
Lack of features of narcolepsy.
INVESTIGATIONS
Diagnosis is clinical. No differentiating test.
Hypersomnia due to medications
SIGNS / SYMPTOMS
History of medication use.
Temporal association of symptoms with use of medication.
INVESTIGATIONS
No need for polysomnogram, unless to exclude other conditions.
Challenge/withdraw/rechallenge.
Hypersomnia due to known physiologic condition
SIGNS / SYMPTOMS
Medical history (e.g., hydrocephalus).
INVESTIGATIONS
Diagnosis is clinical. No differentiating test.
Hypersomnia associated with psychiatric conditions
SIGNS / SYMPTOMS
Psychiatric history: for example, of depression or of anxiety.
INVESTIGATIONS
Treatment of underlying condition solves the excessive daytime sleepiness.
Idiopathic hypersomnia
SIGNS / SYMPTOMS
Naps do not improve excessive daytime sleepiness and are typically not refreshing; long habitual sleep duration in some patients; sleep inertia or “drunkenness” (inability or extreme difficulty in morning awakening).
Lack of features of narcolepsy.
INVESTIGATIONS
Diagnosis of exclusion.
Can include short or long habitual sleep duration.
Polysomnogram and multiple sleep latency test (MSLT) often needed to exclude other conditions.
MSLT finds shortened sleep latency with (usually) <2 sleep-onset rapid eye movement periods.
Kleine-Levin syndrome
SIGNS / SYMPTOMS
Recurrent episodes of excessive daytime sleepiness of 2 to 14 days' duration, at least yearly and associated with behavioral changes but normal cognition, alertness, and behavior between the attacks.
Lack of features of narcolepsy.
INVESTIGATIONS
Diagnosis is clinical. No differentiating test.
Menstrual-related hypersomnia
SIGNS / SYMPTOMS
Occurs exclusively in women.
Episodes start after menarche, last up to 1 week, occur almost monthly, with rapid resolution at the time of the menses.
Lack of features of narcolepsy.
INVESTIGATIONS
Diagnosis is clinical. No differentiating test.
Hypersomnia responds to hormonal therapy.
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