Narcolepsy is characterized mainly by daytime sleepiness, this being the most visible symptom of all and the one that appears from early stages to severe ones.
The most common of the narcolepsy symptoms, besides occurring episodes of daytime sleepiness, is cataplexy, which occurs at about 70% of the patients. Hipnagogic hallucinations and sleep paralysis occur less frequently. However, only 10-25% of the patients present all four major symptoms of the narcolepsy during disease manifestation.
The four major narcolepsy symptoms are:
- daytime sleepiness
Narcolepsy symptoms – daytime sleepiness
Episodes of daytime sleepiness are usually the first of the narcolepsy symptoms. They interfere with daily activities, whether or not the patient sleeps enough during the night. If the drowsiness intensifies, it may be accompanied by confusion, lack of energy, depression or deep state of fatigue and in some cases, memory loss. Episodes are usually brief, lasting only a few seconds, 40% of the patients also show an automatic behavior during such periods.
If the episode occurs while they are performing a task, the process apparently continues without interruption : patients have clear memories about the seconds spent during the “microsleep”, but the capabilities are reduced to minimum during them: for example, if the episode occurs while the patient writes letters, they will become unintelligible, more like a smudge. Moreover, this symptom makes the disease quite easy to identify.
Narcolepsy symptoms – cataplexy
Another important narcolepsy symptom is cataplexy. Cataplexy is the sudden loss of muscle tone, resulting in muscle weakness and loss of muscular control. In about 10% of the cases, cataplexy is the first major symptom of narcolepsy. Unfortunately, the symptom is often wrongly diagnosed as a manifestation of seizures. Attacks vary in duration and severity.
The most serious of these involves a complete loss of muscle tone, collapse, the inability to speak, keep your eyes opened or move. During the episodes of cataplexy, patients remain fully aware. This thing is useful in order to distinguish cataplexy from seizures, also during the differential diagnosis. Although cataplexy can occur without an apparent reason, it is usually triggered by emotional factors such as strong fear, laughter or anxiety.
Narcolepsy symptoms – paralysis and hallucinations
Sleep paralysis is characterized by failure of speech and movement, which usually occurs before we get asleep or when we wake up. This natural condition usually passes unnoticed to those who do experience narcolepsy symptoms, taking into account that occurs when the person is fully asleep and entering the REM (rapid eye movement) sleep phase. Although it may seam frightening, especially when they are experienced for the first time, fortunately sleep paralysis or cataplexy do not leave permanent scars.
Hallucinations can accompany sleep paralysis or may appear as an isolated narcolepsy symptom when trying to sleep or when they wake up. The hallucinations are usually visual, but may also involve all the senses.
Narcolepsy symptoms occurrence
Narcolepsy symptoms first appear when the patient is between 10 and 25 years, but clinically, narcolepsy can occur at any age. Many patients feel the first symptoms between 35 and 45 years and the percentage decrease when talking about individuals between 50-55 years. Regardless of the age at which it triggers, symptoms tend to worsen over the next 20-30 years; in some patients they decrease in severity after the age of 60.