Recurrent Hypersomnia

Essential Features
Recurrent episodes of hypersomnia
Last a few days to several weeks
Occur once to 10 times a year
Prodrome of fatigue or headache may precede episodes
Sleep may last 16 to 18 hrs. per day
Weight gain often occurs
Cognitive Abnormalities: feelings of unreality, confusion, hallucinations
Behavioral Abnormalities: binge eating, hypersexuality, irritability, aggressiveness
Episode Termination associated with amnesia, transient dysphoria or elation, insomnia
Sleep and general behavior must be normal between episodes

Associated Features
Occasional reddish face with severe perspiration
Social and occupational impairment during attacks

Rare – ~ 200 cases reported
Male to female ratio 4:1

Predisposing Factors
Increase frequency of HLA DQB1* 02
Precipitating Factors
Flu-like or upper airway infection
Head trauma
Exposure to anesthesia
Familial Patterns

Onset, Course and Complications
Early adolescence age of onset
Recurrent episodes of severe sleepiness
Episodes last up to several weeks
Normal functioning between episodes
Duration, severity and frequency lessen over several years
Complications mainly social and occupational

Pathology and Pathophysiology
Inconsistent findings
lymphocytic infiltrations in the hypothalamus, amygdala and temporal grey matter (one case reported)
Symptoms may be of hypothalamic origin
In a few cases, moderately and transitory decreased CSF hypocretin-1 levels during episodes of hypersomnia

Diagnostic Criteria
Recurrent episodes of excessive sleepiness
of 2 days to four weeks duration
Episodes recur at least once a year
Normal alertness, cognitive functioning,
and behavior between attacks
Hypersomnia not better explained by another sleep disorder, medical or neurological disorder, mental disorder, medication use, or substance use disorder



Clinical and Pathophysiologal subtypes

Kleine-Levin Syndrome:
This is a condition associated with excessive somnolence which may last for a few days to several weeks and can occur between one to ten times in a year. Individuals may sleep up to 16 hours a day and typically wake up just to void and eat. The patients tend to have neurocognitive manifestations such as hypersexuality, irritability and aggressiveness. Physical manifestations may include a reddish face with associated severe sweating.
Extremely rare disorder with male predominance, 4:1.
Flu like illnesses have been reported prior to the onset of the first episode in some cases.
Symptoms usually begin to occur in early adolescence and the median range for symptoms is 4 years in this self limiting condition. Differential diagnosis of waxing and waning sleepiness include, tumors in the 3rd ventricle, bipolar disorder, seasonal affective disorder and other disorders of excessive sleepiness including extrinsic disorders like sleep apnea, periodic limb movement in sleep and seizure disorders.

Recurrent episodes of hypersomnia clearly associated with behavioral abnormalities
Binge eating
Irritability, aggression and odd behavior
Cognitive abnormalities (feelings of unreality, confusion, and hallucinations)
Common Symptoms
Hypersomnia 100%
Cognitive changes 96%
Eating disorders 80%
Hypersexuality 43%
Compulsions 29%
Depressed mood 48%
Precipitating Factors
Infection 38%
Head Trauma 9%
Alcohol Consumption 5.4%
Somnolence ↓ with stimulants in 40% of cases
Neuroleptics and antidepressants poor benefit
Lithium, not carbamazepine or other antidepressants, stopped relapses 41%
Lasted longer in women
Secondary cases (stroke, hematoma, MS, developmental disease, encephalitis) had more frequent and longer episodes