For people with narcolepsy, however, REM sleep occurs
There are two main types of narcolepsy: type 1 and type 2.
within 15 minutes in the sleep cycle and intermittently during the waking hours. It is during REM sleep that vivid dreams and muscle paralysis occur.Type 1 involves sleepiness and cataplexy. Tests will show that the person is almost entirely missing a neurotransmitter known as hypocretin. This may occur after an infection triggers an autoimmune condition.
Type 2 mainly involves excessive daytime sleepiness, but there is usually no sudden weakness.
Secondary narcolepsy can result when trauma or a tumor results in damage to the hypothalamus. This is a part of the brain involved in sleep.