Narcolepsy is a neurological sleep disorder that can cause excessive daytime sleepiness and, in some people, cataplexy and other symptoms around sleep and wake transitions. Other causes of sleepiness can look similar, so careful Sleep Medicine evaluation is important before a diagnosis is made.
The pattern of symptoms matters. Narcolepsy can present differently in different people, and symptoms may overlap with insufficient sleep, sleep apnea, circadian disorders, medication effects and other causes of hypersomnolence.
A persistent tendency to fall asleep or struggle to stay awake during the day despite having an opportunity for sleep.
Brief episodes of muscle weakness triggered by emotions such as laughter, surprise or excitement. Cataplexy is strongly associated with narcolepsy type 1.
Temporary inability to move when falling asleep or waking. It can occur on its own, so it does not by itself establish a diagnosis of narcolepsy.
Vivid dream-like experiences around falling asleep or waking can occur in narcolepsy and other sleep-wake states.
Usually associated with cataplexy and, in appropriate cases, evidence of reduced hypocretin/orexin signalling. The clinical picture and test results are interpreted together.
Characterised by excessive daytime sleepiness without cataplexy, with diagnostic testing used to distinguish it from other central hypersomnolence disorders and insufficient sleep.
Sleep duration, schedules, naps, symptoms, medicines, substances and the timing of sleepiness are reviewed. A sleep diary or other schedule tracking may also be useful.
An overnight sleep study may be used to assess sleep architecture and look for other sleep disorders, including sleep-related breathing disorders, before daytime testing.
In selected patients, a standardized MSLT measures how quickly a person falls asleep across multiple daytime opportunities and evaluates for sleep-onset REM periods.
Insufficient sleep, circadian misalignment, obstructive sleep apnea, medicines, substances and other medical or psychiatric factors may need to be addressed before interpreting hypersomnolence testing.
Management may include behavioural strategies, planned sleep scheduling and, when appropriate, prescription wake-promoting or other therapies for excessive sleepiness and cataplexy. Treatment choices depend on the diagnosis, age, other medical conditions, medicines, safety considerations and response over time.
Dr. Prakash Kothari G provides online Sleep Medicine consultations for adults and children. A consultation can help review the pattern of daytime sleepiness, previous sleep studies, medications, sleep schedules and whether further testing such as PSG/MSLT may be appropriate.
If persistent daytime sleepiness, cataplexy or other unusual sleep-wake symptoms are affecting daily life or safety, a Sleep Medicine assessment can help identify the appropriate next step.