Narcolepsy and Cataplexy

Narcolepsy is a sleep disorder. The principal symptoms are excessive daytime sleepiness (EDS), cataplexy (loss of muscle tone), hypnagogic hallucinations, sleep paralysis, disrupted night-time sleep and automatic behaviour (being unaware of what you are doing). A person suffering from narcolepsy may have some or all of these symptoms.

Excessive daytime sleepiness usually occurs every day, regardless of the amount of sleep obtained at night. EDS is usually experienced as a heightened sensitivity (sometimes an almost irresistible susceptibility) to becoming sleepy or falling asleep, especially in sleep-inducing situations, such as sitting in a comfortable chair.

Patients describe the problem as sleepiness, tiredness, lack of energy, exhaustion or a combination of these feelings, either continuously or at various times throughout the day. Sometimes sleepiness occurs so suddenly and with such overwhelming power that it is referred to as a 'sleep attack' . Some people have many 'sleep-attacks' each day, the duration ranging from a few seconds to several minutes, and may be unaware of their occurrence. Occasionally attacks may last for several hours. Narcoleptic sleep attacks are thought by some authorities to be the inappropriate appearance of REM sleep.

Cataplexy is an abrupt loss of voluntary muscle tone, usually triggered by emotional arousal. Attacks can range in severity from a brief sensation of weakness to total physical collapse lasting several minutes. Hypnagogic hallucinations are intense, vivid dreams, sometimes ccompanied by frightening auditory, visual and tactile sensations, and usually occur just on wakening or falling asleep, but may occur at other times. They are often xtremely difficult to distinguish from reality.

Attacks of Cataplexy

Episodes of muscular weakness which, depending on the severity of the attack, show up as anything from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees, or total collapse on the floor. Speech is slurred, eyesight impaired (double vision, inability to focus) but hearing and awareness remain undisturbed. These attacks are triggered by strong emotions such as exhilaration and laughter, anger and surprise. Cataplexy may be most severe when the subject is tired rather than fully alert and can lead to considerable anxiety although anxiety itself is not a trigger The attacks last some minutes and may end in resumption of normal behaviour or the sufferer may slip into sleep sometimes of extended duration.

Essentially, cataplexy is a symptom only found in narcolepsy and thus the presence of it makes diagnosis of narcolepsy much more certain.

Sleep paralysis is the inability to move when waking up or falling asleep. This may be momentary, or longer, or multiple attacks may occur. This condition can be terrifying, especially if it occurs with a frightening hypnagogic hallucination.