narcolepsy

what is narcolepsy

rare neurological disorder where individual has many daytime sleep episodes despite adequate night sleep

why is narcolepsy unique among sleep disorders

represents abnormalities in wake/sleep generators

what are the main symptoms of narcolepsy

• excessive daytime sleepiness

• cataplexy

• hypnagogic/hypnopompic hallucinations

• sleep paralysis

what is cataplexy

sudden brief muscle weakness triggered by emotions

symptoms of cataplexy

• eye sagging

• head dropping

• knees buckling

how long does cataplexy episodes last

seconds to minutes

true or false: cataplexy can precede to excessive daytime sleepiness (EDS)

true - attacks can occur suddenly

what is hypnopompic hallucination

vivid dreamlike hallucination that occurs as one is waking up

what is hypnagogic hallucination

hypnagogic hallucinations occur when one is falling asleep

transition from wakefulness to sleep

what is difference between hypnagogic and hypnopompic hallucinations

• Hypnagogic: occur at sleep onset

• Hypnopompic: occur when waking

what is sleep paralysis

when REM atonia sets in sooner than usual, before the person is fully asleep or persists longer than usual after the person has fully woken up

what happens during hypnagogia hallucinations

• dreams

• can be narrative

• often frightening

• auditory hallucination

what neurotransmitter system is involved in narcolepsy

orexin system

how does orexin system cause narcolepsy

loss of orexin neurones or receptor dysfunction

posterior hypothalamus damage promotes hypersomnolence

what treatments are used for narcolepsy

• Amphetamine derivatives

• Antidepressants (for cataplexy)

• Benzodiazepines

• Modafinil

difference between orexin type 1 and type 2 receptor signalling in narcolepsy

the absence of both Orexin Type 1 (OX1R) and Orexin Type 2 (OX2R) receptor signaling leads to distinct, yet complementary, dysregulations of the sleep-wake cycle

1. OX2R Loss: Triggers uncontrolled daytime sleepiness (inability to stay awake).

2. Both Lost: Triggers the inability to inhibit REM sleep during the day (cataplexy, sleep paralysis, hallucination).

what drugs are used to manage excessive daytime sleepiness

• methylphenidate

• dextroamphetamine

• methamphetamine

• modafinil

name some drugs used to treat cataplexy

• fluoxetine

• clompirpamine

• protriptyline

name some drugs used to treat distrupted night sleep

• zolpidem

• gamma-hyroxybutyrate

what is Modafinil and why is it contraversional

cognitive enhancer used for EDS; evidence for improving attention or memory is weak