150 Primary Hypersomnia (307.44)

DSM-IV-TR criteria

• The patient experiences excessive sleepiness for at least one month. This can include prolonged sleep at night or additional sleep in the daytime.
• The patient experiences significant distress or functional impairment due to excessive sleepiness.
• The excessive sleepiness is not better accounted for by insomniaand does not occur exclusively during the course of another Sleep Disorder (e.g. Narcolepsy, Breathing-Related Sleep Disorder, Circadian Rhythm Sleep Disorder, or a Parasomnia) and cannot be accounted for by an inadequate amount of sleep.
• The disturbance does not occur exclusively during the courseof another mental disorder.
• The condition cannot occur exclusively with any other mental disorder, physical medical condition, or substance use.

Proposed DSM 5 changes (DSM5.org)

A. The predominant complaint is unexplained hypersomnia (excessive sleep) or/and hypersomnolence (sleepiness in spite of sufficient nocturnal sleep), for at least 3 months, occurring 3 or more times per week.1. Hypersomnia (excessive sleep) is defined by a prolonged nocturnal sleep episode or daily sleep amounts (>9 hours/day).2. Hypersomnolence is defined by excessive daytime sleepiness with recurrent daytime naps or lapses into sleep that occurs daily or almost daily over at least the last 3 months (when the patient is untreated) and daily sleep amounts > 6 hours. To document hypersomnolence, the Multiple Sleep Latency Test must show a mean sleep latency below 8 minutes, with or without Sleep Onset REM Periods (SOREMPs). If the patient has more than 2 SOREMPs, the condition may be called “narcolepsy without cataplexy”. B. The sleep periods are non-restorative (unrefreshing) or so prolonged in length that this causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.C. The hypersomnia is not better accounted for by insomnia and does not occur exclusively during the course of another Sleep Disorder (e.g., Narcolepsy with Cataplexy, Sleep-Related Breathing Disorder, Circadian Rhythm Sleep Disorder, or a Parasomnia) and cannot be accounted for by an inadequate amount of sleep. D. The disturbance does not occur exclusively during the course of another mental or medical disorder but may occur simultaneously with these disorders.E. The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication).

Clinically Comorbid Conditions:

1. Mental/Psychiatric Disorder (specify)
2. Medical Disorder (specify)

Rationale:

• Narcolepsy without cataplexy is defined based on a positive Multiple Sleep Latency Test but no cataplexy. Its symptoms are identical to hypersomnia without long sleep time. Most of these cases are not caused by hypocretin deficiency. The treatment of narcolepsy without cataplexy is similar to that of primary hypersomnia. There is no proof that narcolepsy without cataplexy and primary hypersomnia are distinct disease entities. Advantage: Simplifies the classification. Disadvantage: Some patients with “narcolepsy” but without cataplexy/hypocretin deficiency (generally narcolepsy without cataplexy) would now go into the category 307.44 “primary hypersomnia/narcolepsy without cataplexy”. As the cause of 307.44 is unknown, this is a “softer” diagnosis.

Criterion A:

Rationale, advantage and disadvantage: It is not a major change, but rather a clarification. The term “Hypersomnia” originally meant “increased sleep amounts”; it is distinct from “hypersomnolence (daytime sleepiness). The The two interacts, and both may be present. There are no disadvantages. The three month criteria is more standard.

Criterion B:

• Rationale, advantage and disadvantage: It is not a major change, but rather a clarification. By definition, sleep must be non-restorative or unrefreshing and cause distress. If the subjects sleeps a lot but feels fine, he/she would be characterized as a long sleeper. It would really become pathological only if extremely long and unmanageable socially.

Criterion C, D, & E: are primarily in the wording.

Relationship to International Classification of Diseases -10:
Nonorganic hypersomnia F51.1, Disorders of Excessive Somnolence (hypersomnias) G47.1

Relationship to International Classification of Sleep Disorders 2nd edition: The revised classification will remain similar to that of the ICSD-2, except that two instead of 4 categories are included. Primary hypersomnia/narcolepsy without cataplexy will be a category merging ICSD-2 narcolepsy without cataplexy, hypersomnia with long time sleep, and narcolepsy without long time sleep. As these three entities are not known to be pathophysiologically distinct, and are treated and evaluated similarly. Narcolespy withou cataplexy 347.00

Severity:

1. Epworth sleepiness Scale

2. Multiple Sleep Latency Test
3. Maintenance of Wakefulness test