Symptoms and Signs:
Symptoms typically start at a young age and continue throughout life, i.e., there is usually a history of episodes. Symptoms are subtle at first and become more severe over time.
Excessive Daytime Sleepiness (EDS), cataplexy, sleep paralysis, and hypnagogic hallucinations are the four classic symptoms that define narcolepsy and are outlined below. Note that only 10 percent of people with narcolepsy experience all four of these symptoms, making the disorder difficult to accurately diagnose.
Excessive Daytime Sleepiness
Excessive Daytime Sleepiness, or sleep attack, is an irresistible urge to fall asleep. It occurs daily, regardless of the amount of sleep obtained at night, and especially during meetings, lectures, and other sleep-inducing situations. You are likely sleepy, tired, exhausted, and lack energy, though feel refreshed after an episode. EDS is also described as having "sleep attacks" since sleep can come on very suddenly and without warning -- even in mid-conversation. Several attacks can occur in a day. It is ironic that people with EDS usually receive poor quality, frequently interrupted, nighttime sleep.
Cataplexy
Cataplexy is the sudden loss of voluntary muscle tone and is usually triggered by strong emotions such as fear, anger, or laughter. You may have a slight feeling of weakness via a nodding head or weak knees, or you may completely collapse for several minutes.
Sleep Paralysis
Sleep paralysis is the inability to move or talk for approximately one minute. Usually occurs when waking up or falling asleep.
Hypnagogic Hallucinations
Hypnagogic hallucinations are intense, vivid, realistic dreams that occur when falling asleep or awakening. They are occasionally difficult to distinguish from reality and may be accompanied by frightening sounds or feelings.
Other Symptoms
A number of studies have found certain common gene sequences in narcoleptics. Narcolepsy also tends to run in families.
Other general symptoms include anxiety, automatic behaviour (performing a task with no memory recall of having done or completed the action), blurred or double vision, depression, disrupted nighttime sleep, headaches, high insulin levels, hypoglycemia, leg cramps, memory difficulties, and improper nervous system function.
