Idiopathic hypersomnia

This article includes discussion of idiopathic hypersomnia (IH), which is characterized by excessive daytime sleepiness, difficulty awakening (sleep drunkenness), and undisturbed overnight sleep without cataplexy or known cause of excessive sleepiness. Excessive sleepiness (hypersomnolence) of unknown etiology, which cannot be explained by another disorder, would be considered idiopathic hypersomnia. This should be clearly distinguished from other disorders that could present with complaints of excessive daytime sleepiness, such as narcolepsy, behaviorallyinduced insufficient sleep, circadian rhythm disturbance, obstructive sleep apnea, or from hypersomnolence secondary to a medical condition or medication. These patients frequently present in adolescence and may have symptoms of autonomic nervous system dysregulation, but they are most often affected because of inability to attend to daytime obligations such as school or work. Because the pathophysiology is unknown, management is limited to symptomatic treatment and education.