Sleep related disorders & hypoventilation Flashcards
A 20 year old has daytime sleepiness interrupting work and social life. At night she falls asleep within 30mins of going to bed but feels unrefreshed on waking. She sleeps alone but does not think she snores significantly. She drinks 5 cups of coffee a day including in the evenings but this does not seem to help keep her awake. She falls asleep in meetings or at work several times a day for just a few minutes, but also has trouble concentrating. She has nightmares where she wakes in terror and is unable to move. As she is falling asleep she often thinks she hears her phone ring, but she has no missed calls when she checks.
Which ONE of the following is the single best investigation to confirm the diagnosis?
A. Actigraphy
B. Lumbar puncture
C. Multiple Sleep Latency Test
D. Overnight oximetry
E. Whole genome sequencing
C. Multiple Sleep Latency Test
The diagnosis in this case is narcolepsy. This is suggested by daytime sleepiness in a young person with inability to resist sleep at inappropriate moments (eg at work), and associated features of sleep paralysis and hypnagogic hallucinations. In this case there is no evidence of cataplexy, but this may develop later in the disease course, or this may be a form of narcolepsy without cataplexy. The multiple sleep latency test woud not only show short sleep latency but also that the patient passes directly into REM sleep a core feature of narcolepsy.
