Narcolepsy Flashcards
Epidemiology?
1 in 2000 people are affected
Onset?
Between 10 and 20years presents with sudden onset of persistent daytime sleepiness
Useful diagnostic clue in history?
They feel refreshed after a full night’s sleep
What is the characteristic feature?
Disturbance in rapid eye movement sleep which can occur any time and lead to unusual states between sleep and wakefulness
Hypnopompic and hypnogogic hallucinations
What is cataplexy?
It is one of the REM like states
Sudden episodes of partial or complete paralysis of voluntary muscles sometimes causing the person to fall on the ground
Occurs in Type 1 Narcolepsy only
Additional features or associations?
Obesity
Depression
What are the types of narcolepsy?
Type 1 - characterized by cataplexy and marked reduction of a peptide called Orexin A in CSF
It is secreted by hypothalamic neurons. Severe selective loss causes reduction
Type 2- no cataplexy normal CSF orexin A levels
Diagnosis is challenging. Biology is less well understood.
Is there a genetic association?
HLADQB1*06:02
Is affected in more than 98% of Type 1 narcolepsy
Other genes of immune function
Is narcolepsy and autoimmune disease
New evidence are suggestive of that
Can be triggered by infections and other stimuli
Onset is common in late spring after streptococcal infections
Influenza vaccine in children had caused