Sleep at inopportune moments
What is a narcolepsy?
Narcolepsy is an uncommon condition affecting around 3 people in every 10,000. Even though it is uncommon, many people have heard of narcolepsy and know that one of the features of narcolepsy is difficulty staying awake. People with narcolepsy have difficulty staying awake and have a tendency to fall asleep quickly and often unexpectedly. In addition to this, patients with narcolepsy can experience sudden onset of muscle weakness triggered by strong emotions such as laughing or anger, a feeling of paralysis on waking, and vivid dreams whilst going to sleep.
What causes narcolepsy?
Recent research on narcolepsy has shown that narcolepsy is due to damage to a small group of cells in the brain that produce the neurotransmitter orexin or hypocretin. It is not clear what causes these orexin producing cells to become damaged, but this process can be triggered by infection or illness. Symptoms most commonly develop in late teenage years, and once established, symptoms persist.
How is narcolepsy diagnosed?
It is not unusual for people with narcolepsy to be diagnosed with other conditions such as depression or psychosis, because of the tiredness and hallucinations, but if cataplexy (sudden muscle weakness) is present the diagnosis is quite clear. To confirm a diagnosis and rule out other conditions contributing to sleepiness, a sleep study followed by a daytime napping test – a multiple sleep latency test – is usually performed.
Once the diagnosis of narcolepsy is confirmed, treatment consists of using napping and sleep scheduling strategies as well as medications to manage sleepiness, cataplexy and other symptoms of narcolepsy. Current medications used to treat sleepiness include modafinil and dexamphetamine, and cataplexy is usually treated with anti-depressant medications. In the future we hope to be able to treat narcolepsy with orexin replacement and there is active research underway to make this a reality.
For more information on narcolepsy, the Stanford University School of Medicine, Center for Narcolepsy website is an excellent resource.