National Sleep Foundation

Chapter 4: Primary Hypersomnias

Assessment and Diagnosis

Idiopathic hypersomnia is diagnosed only after ruling out other possible causes, including: Behaviorally-induced ISS, delayed sleep phase syndrome, periodic limb movement disorder, sleep-related disordered breathing, narcolepsy, and secondary hypersomnia.76  In addition, the hypersomnia symptoms may not be caused by a different sleep disorder, medical disorder, psychiatric disorder, or by medication or substance abuse.77

Among those with idiopathic hypersomnia, polysomnography (PSG) shows “short sleep latency, a major sleep period of more than 10 hours, with laborious wakening in the morning or from naps, in the polysymptomatic form, or a major sleep period of 6 to 10 hours in the oligosymptomatic form.”78  The MSLT shows a mean latency of less than eight minutes and no sleep-onset REM periods.79

References

  1. Bassetti C, and Y Dauvilliers, “Idiopathic Hypersomnia,” In: Kryger MH, Roth T III, Dement WC, eds. Principles and Practice of Sleep Medicine (5th edition), Philadelphia, Pa: Elsevier Saunders; 2011:969-979.
  2. Billiard M, Dauvilliers Y. Idiopathic hypersomnia. Sleep Med Rev. 2001;5:349-358.
  3. Billiard M, Dauvilliers Y. Idiopathic hypersomnia. Sleep Med Rev. 2001;5:349-358.
  4. Billiard M, Dauvilliers Y. Idiopathic hypersomnia. Sleep Med Rev. 2001;5:349-358.