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Idiopathic Hypersomnia

By

Richard J. Schwab

, MD, University of Pennsylvania, Division of Sleep Medicine

Last full review/revision Jun 2020| Content last modified Jun 2020
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Idiopathic hypersomnia is excessive daytime sleepiness with or without a long sleep time; it is differentiated from narcolepsy by lack of cataplexy, hypnagogic hallucinations, and sleep paralysis.

Idiopathic hypersomnia is not well-characterized. Cause is presumed to be dysfunction of the central nervous system.

Excessive daytime sleepiness is the main symptom; sleep time may or may not be prolonged.

Diagnosis of Idiopathic Hypersomnia

  • History or sleep logs

  • Sleep tests

In idiopathic hypersomnia with a long sleep time, the history or sleep logs indicate > 10 hours of nocturnal sleep; in idiopathic hypersomnia without a long sleep time, it is > 6 hours but< 10 hours. In both cases, polysomnography shows no evidence of other sleep abnormalities. Multiple sleep latency testing shows short sleep latencies (< 8 minutes) with fewer than 2 REM periods.

Treatment of Idiopathic Hypersomnia

  • Similar to that of narcolepsy

Treatment of idiopathic hyperinsomnia is similar to that of narcolepsy (eg, modafinil), except that anticataplectic drugs are unnecessary.

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Numbness
Numbness is defined as loss of sensation, either partial or complete. Numbness can occur from dysfunction anywhere along the pathway from the sensory receptors up to the cerebral cortex. A patient with dysfunction in which of the following CNS areas is most likely to present with facial and body numbness on the same side, plus an inability to perceive multiple stimuli of the same type simultaneously?
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