Sleepiness & Narcolepsy
Daytime sleepiness, the tendency to want to doze off during the day or to not be able to avoid dozing off, is not normal when it occurs after adequate sleep, which is 7 to 8 hours for most adults. The symptom can be caused by sleep disorders characterized mostly by nocturnal events, like obstructive sleep apnea (OSA), and by primary disorders of daytime sleepiness, like narcolepsy; there is often more than one contributing diagnosis. Sleep testing is almost always needed so treatment can be specific.
The two most common nocturnal sleep disorders are OSA and Periodic Limb Movement Disorder (PLMD).
Each has very specific treatment options, and frequently, daytime sleepiness will be resolved with regular therapy.
Idiopathic hypersomnia (IH) is another chronic neurologic disorder that is less well understood. While daytime sleepiness can be similar to narcolepsy, daytime naps are often long and unrefreshing. Another hallmark is sleep inertia, or “sleep drunkenness”, which is trouble waking up even after very long sleeps, with confusion and disorientation. There may be coexistent cardiometabolic conditions and/or dysautonomia.
Narcolepsy is a chronic neurologic disorder in which the brain’s ability to regulate the sleep-wake cycle is affected. While very sleepy during the day, often the patient cannot sleep well at night. There can be uncontrollable “sleep attacks” and intense daytime sleepiness, there are often symptoms affecting REM sleep instability (cataplexy and sleep paralysis). Treatment is mostly behavioral and medication to manage symptoms.