Overnight sleep may be disturbed as well. People with narcolepsy are more likely to go into rapid eye movement (REM) sleep within the first hour after falling asleep (and often within the first 15 minutes). Sleep is also more fragmented with frequent transitions between sleep stages.
Daytime sleepiness may result in double or blurred vision and automatic behaviors such as “zoning out” while driving. The Epworth sleepiness scale identifies the degree of excessive sleepiness. Scores higher than 15 out of 24 are often reported by narcoleptics.
Sleepiness in narcolepsy typically improves after a brief nap. And narcoleptics typically wake up feeling refreshed in the morning.
Hypnagogic hallucinations result when REM sleep and associated dreaming, mixes with wakefulness. These hallucinations are often visual, but other experiences may occur as well.
In addition, there may be accompanying feelings of suffocation or even a looming presence within the room. The episodes tend to be quite frightening. Though they may occur ordinarily, especially during sleep disruptions, they also are a sign of narcolepsy.
It typically lasts only a few minutes and consciousness remains intact. Severe episodes may cause falls.
Interestingly, cataplexy occurs in almost no other disorder. So, if it is present, narcolepsy with cataplexy (or type 1 narcolepsy) is the likely diagnosis. Its presence again relates to an intrusion of REM sleep into wakefulness, for paralysis normally occurs when we are asleep so that we do not act out our dreams.
