Idiopathic hypersomnia with long sleep time
is characterized by pervasive daytime sleepiness
despite longer-than-average nighttime sleep.19,20
Prolonged nighttime sleep of 10 h with few or no
awakenings still leave affected patients unrefreshed
or confused (sleep drunkenness) on morning
waking. Daytime naps tend to be longer and less
refreshing than those of narcoleptic patients. The
condition most often develops during the early
adulthood with a chronic but stable course.