Daytime Sleepiness

Aka: Daytime Sleepiness, Sleepiness, Daytime Tiredness, Hypersomnia, Hypersomnolence, Disorder of Excessive Daytime Sleepiness

1. See Also
   1. Sleep Stage
   2. Hypersomnolence Causes
   3. Narcolepsy
   4. Insomnia
2. Causes
   1. Hypersomnolence Causes
3. History
   1. History of Sleepiness
   2. Comorbid significant medical conditions (e.g. Neurologic Disorders)
   3. Medications (including non-prescription items, supplements and herbals)
   4. Alcohol and other drugs of abuse
   5. Mood and emotional stressors
   6. Lifestyle, night-time work hours, and sources of sleep deprivation
   7. Sleep habits (including Insomnia, snoring, and possible Sleep Apnea)
   8. Restless Leg Syndrome
4. Screening: Significant daytime somnolence indicating additional evaluation
   1. Falling asleep while driving OR
   2. Epworth Sleepiness Scale >12
5. Differential Diagnosis
   1. Insomnia (Disorder of Initiating and Maintaining Sleep or DIMS)
      1. Insomnia typically causes paradoxical daytime hyperarousal instead of Sleepiness
      2. Insomnia with excessive Daytime Sleepiness suggests comorbidity (e.g. Sleep Apnea)
6. Labs
   1. Thyroid Function Tests
   2. Renal Function tests
   3. Serum Calcium
   4. Arterial Blood Gas (ABG)
      1. Rule-out Hypercapnia
7. Diagnostics: Sleep Study
   1. Step 1: Overnight polysomnography evaluates for Sleep Apnea
      1. Positive: Treat Sleep Apnea
      2. Negative: Perform step 2 testing
   2. Step 2: Polysomnography evaluates sleep onset latency (time to fall asleep)
      1. Multiple Sleep Latency Test (MSLT)
         1. Hypersomnolence with early onset REM Sleep diagnoses Narcolepsy without cateplexy
      2. Maintenance of Wakefullness Test (MWT)
         1. Assess waking performance in alertness-critical professions (e.g. drivers, pilots)
8. Management: General
   1. Treat underlying cause (e.g. Sleep Deprivation, Sleep Apnea, Restless legs syndrome)
   2. Practice Sleep Hygiene and ensure adequate sleep time
9. Management: Stimulant Medications
   1. See Narcolepsy for specific management
   2. Contraindications
      1. Untreated Sleep Apnea
      2. Other secondary causes not fully excluded
      3. Mild or unproven Hypersomnolence
   3. Indications
      1. Excessive Sleepiness despite appropriate Sleep Apnea management with CPAP
      2. Daytime Sleepiness with shift work disorder
      3. Other moderate to severe excessive Daytime Sleepiness
   4. First-line agents
      1. Modafinil (Provigil)
         1. Best safety profile and lowest abuse potential of all stimulant agents
         2. Czeisler (2005) N Engl J Med 353(5): 476-86
   5. Other agents (higher risk of abuse and side effects)
      1. Dextroamphetamine (Dexedrine)
      2. Methylphenidate (Ritalin)
      3. Pemoline (Cylert)
         1. Risk of hepatotoxicity
10. References
    1. Kreiger (2000) Sleep 23:S95-8
    2. Pagel (2009) Am Fam Physician 79(5): 391-6