Symptoms that may occur in narcolepsy (but not always):
- Cataplexy – a sudden loss of muscle tone, often triggered by laughing, crying or strong emotions.
- Sleep paralysis – this usually occurs when waking up in the morning and lasts usually for 1 minute or less. It can be a frightening experience but it is not dangerous or harmful.
- Hypnagogic hallucinations are dream-like experiences that occur when a person is about to fall asleep (but not yet asleep). Hypnapompic hallucinations are similar but occur when waking up in the morning.
Narcolepsy is due to damage to a small group of cells in the brain that produce the neurotransmitter hypocretin (also known as orexin). We do not have a full understanding and how and why this damage occurs, but recent research suggests an autoimmune process.