Primary Hypersomnia Clinical Presentation

Updated: Sep 04, 2018
  • Author: Adrian Preda, MD, DFAPA; Chief Editor: Ana Hategan, MD, FRCPC  more...
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The diagnostic criteria of idiopathic hypersomnia in ICSD-3 includes both objective testing parameters and clinical criteria, which are similar to DSM-5 criteria: [17, 48, 49]

  • Daily periods of irresistible need to sleep or daytime lapses into sleep for more than 3 months

  • Absence of cataplexy

  • MSLT showing < 2 SOREMPs or no SOREMPs if the REM sleep latency preceding polysomnogram is 15 minutes or less

  • The presence of at least one of the following:

    • MSLT showing a mean sleep latence of 8 minutes or less

    • Total 24-hour sleep time of 660 minutes or longer (typically 12 to 14 hours) on 24-hour polysomnography monitoring (performed after the correction of chronic sleep deprivation) or by wrist actigraphy in association with a sleep log (averaged over at least 7 days with unrestricted sleep)

  • Insufficient sleep syndrome ruled out (if deemed necessary, by lack of improvement of sleepiness after an adequate trial of increased nocturnal time in bed, preferably confirmed by at least 1 week of wrist actigraphy)

  • Hypersomnolence or MSLT findings that are not better explained by another sleep disorder, medical or neurologic disorder, mental disorder, medication use, or substance abuse. Drugs known to affect sleep, sleep latency, and daytime alertness must be carefully evaluated and should be withdrawn for a minimum of 2 weeks before objective tests.

Additional characteristics

The most typical referral is for the polysymptomatic form of primary hypersomnia and is characterized by the following: [1, 60]

  • Excessive daytime sleepiness leading to prolonged naps that are not refreshing

  • Sleep drunkenness

These patients do not feel refreshed following naps and, therefore, fight sleepiness as long as they are able. Patients are difficult to awaken from sleep or naps.

Some patients complain of headaches, fainting episodes, orthostatic hypotension, and peripheral vascular complaints of Raynaud phenomenon. Rarely, hypnagogic hallucinations and sleep paralysis may be observed. During long periods of drowsiness, patients might develop automatic behavior, during which they act in a semicontrolled fashion. (During automatic behavior episodes, these patients may endanger themselves through risk of injury.)

In patients with the recurrent form (i.e., Kleine-Levine syndrome), hypersomnia occurs for days to weeks several times a year. In between, patients do not have excessive daytime sleepiness. Some patients may develop symptoms of irritability, hypersexuality, hyperphagia, impulsive behavior, depersonalization, hallucinations, depression, and disorientation.


Physical Examination

The patient may appear overtired or even fall asleep in the physician’s office. The rest of the physical examination, however, will not reveal any particular features suggesting a diagnosis of hypersomnolence.

The physical examination goal is to exclude alternate diagnoses. A diagnosis of obstructive sleep apnea rather than hypersomnolence should be considered for a patient presenting with hypersomnia associated with central obesity, micrognathia or retrognathia, macroglossia, crowded oropharynx, nasal obstruction, and tonsillar enlargement.

An underlying rheumatologic disease, such as active rheumatoid arthritis or osteoarthritis, may cause daytime hyperoxia and sleepiness associated with poor nighttime sleep due to pain. Prior head trauma sequela or a current brain tumor can leave their specific mark on the neurologic examination.

Specific findings may suggest a degenerative neurologic condition (e.g., Parkinson or Huntington disease), endocrine dysfunction (e.g., hypothyroidism), viral and bacterial infections (e.g., hypersomnia secondary to viral encephalitis), pulmonary disease with secondary sleep-related breathing difficulties (e.g., chronic bronchitis) or musculoskeletal disorders (e.g., rheumatoid arthritis, fibromyalgia).

An overweight patient with primary hypersomnia should be assessed for underlying endocrine problems and sleep apnea.

If psychomotor retardation or agitation is noted, mental disorders with secondary sleep disturbance need to be ruled out before making a diagnosis of hypersomnolence.

Mental status examination

Major depressive disorder commonly presents with decreased energy and tiredness and atypical depression presents with hypersomnia. Similarly, speech that is soft in quality, with a decreased rate of production and an increased latency of answers, might indicate excessive tiredness, but it may also indicate depression.

Mood might be “down," tired,” or even “depressed,” with mood congruent and a decreased range of affect. If this is the case, the meaning of the words needs to be carefully qualified. Is it that the patient has depression (ie, major depressive disorder) or is it that he/she feels down as a reaction to oversleeping and decreased ability to function?

Thought processes should be coherent and goal directed. While suicidal ideation is not typical for hypersomnolence, because of the overlap between sleeping and affective disorders, standard questioning about the presence of suicidal and homicidal ideation is recommended.

Insight and judgment are most times good. Mild cognitive changes in the domains of attention, concentration and short-term memory are occasionally present, but most often the cognitive examination should not reveal any significant deficits.

Recurrent hypersomnia

On the neurologic examination, patients with Klein-Levin syndrome may present with a number of nonspecific findings including nystagmus, dysarthria, and generalized hyperreflexia.

For secondary Kleine-Levin syndrome, patients tend to be older and have more frequent and longer episodes, but they present with clinical symptoms and treatment responses similar to those of primary cases. [11]