Narcolepsy in Children
What is narcolepsy?
Narcolepsy is a neurological (nervous system) disorder that affects the brain’s ability to control sleep and wakefulness. Children with narcolepsy experience excessive sleepiness, which impacts all aspects of their life, including social activities and school performance.
Children with narcolepsy experience:
- Constant excessive daytime sleepiness.
- Ongoing struggles to stay awake.
- Sudden sleep episodes (“sleep attacks”) that occur during any type of activity and at any time of the day.
Who gets narcolepsy?
Narcolepsy is underdiagnosed and misdiagnosed in children, making it difficult to determine how many children have the disorder. However, one estimate is that narcolepsy occurs in slightly less than one in every 100,000 children. The symptoms of narcolepsy have been reported in children as young as five or six, but it is often not diagnosed until adolescence or later. Narcolepsy affects an equal number of boys and girls.
Are there different types of narcolepsy?
Yes, there are two types of narcolepsy:
- Narcolepsy Type 1 (previously called narcolepsy with cataplexy [see symptoms section for definition]). Persons with narcolepsy type 1 have excessive daytime sleepiness plus cataplexy and/or low levels of a chemical in the brain called hypocretin. One unique feature of this type of narcolepsy in children is that those who have it tend to experience rapid weight gain.
- Narcolepsy Type 2 (previously called narcolepsy without cataplexy). Persons with narcolepsy type 2 have excessive daytime sleepiness but do not have cataplexy and have normal levels of hypocretin.
What causes narcolepsy?
Narcolepsy is thought to be related to a disruption in an area of the brain that controls sleep and wakefulness. In many cases, it is thought to be due to a loss of a particular chemical in the brain called hypocretin.
Other possible factors scientists think play a role in narcolepsy include:
- An autoimmune disorder: A person’s immune system attacks the brain cells that produce hypocretin, resulting in a shortage of this chemical.
- Family history: Some persons with narcolepsy have close relatives with similar symptoms.
- Brain injury or tumor: In a small number of patients, the area of brain that controls REM sleep and wakefulness can be injured by trauma, tumor or disease.
- Environmental toxins: Pesticides, heavy metals and secondhand smoke.
What are the signs and symptoms of narcolepsy?
Symptoms of narcolepsy vary during a person’s lifetime. Not all of the following symptoms are present at the start of the disorder or in every single child. The four most common symptoms/signs of narcolepsy are as follows:
- Excessive daytime sleepiness (EDS): This is usually the first sign of narcolepsy in children and occurs in all patients. EDS interferes with normal activities (work, school, home life, social activities) every day. Children have frequent bouts of extreme tiredness, most often during inactive times, such as when sitting in the classroom, reading, or riding in a vehicle. Sleep attacks in young children are nearly constant and they last longer than those experienced in adolescents or adults. In preschool children, afternoon naps can last up to two to three hours, but tiredness returns within one to two hours. One unique sign of narcolepsy in children is consistent napping after the age of five or six. Children with EDS report mental cloudiness, forgetfulness, lack of energy, decreased attention and concentration, and poor school performance. Behavioral issues include irritability, aggressiveness, hyperactivity, social withdrawal and depression.
- Cataplexy: Cataplexy is a sudden, brief loss of muscle tone or strength triggered by stress or a strong emotion, such as laughter (common cause in children), excitement, anger, anxiety or surprise. Cataplexy may be mild, like a brief feeling of weakness in the knees or slackness in the jaw or drooping of the eyelids, to total body paralysis with collapse. Additional features unique to children include facial and/or jaw and eyelid weakness and sticking out of the tongue, plus slurred speech, other abnormal facial movements and expressions. Cataplexy usually lasts a few seconds to several minutes. Cataplexy is seen in about 70% of children with narcolepsy. In young children, cataplexy can be mistaken for clumsiness, seizures, a fainting spell or as an attention-seeking behavior.
- Sleep paralysis: This symptom is the inability to move or speak just before falling asleep or just after waking up. Episodes of sleep paralysis usually go away after a few seconds to a few minutes. Being touched by another person usually causes the paralysis to disappear.
- Hallucinations: These are vivid, dream-like/nightmare events that are difficult to distinguish from reality. They occur just before falling asleep (called hypnagogic hallucinations) or just after awakening (called hypnopompic hallucinations). The "dreams" often involve images or sounds of strange animals or prowlers. The content is generally scary. Many times hallucinations appear in combination with sleep paralysis episodes and are part of the dream (REM) intrusion into wakefulness that occurs with narcolepsy.
Other symptoms of narcolepsy can include:
- Disturbed sleep through the night: This is difficulty sleeping through the night because of frequent awakenings.
- Automatic behaviors: This symptom is described as falling asleep for several seconds but continuing to perform routine tasks, such as writing, without any awareness or later memory of ever doing the task.
- Sudden weight gain: This is another symptom or warning sign of narcolepsy in children. It is seen most commonly early in the course of the disorder. Obesity is present in at least 25% of children with narcolepsy.
- Early onset of puberty.