Study on narcolepsy, conducted primarily in university and hospital-related facilities, continues to research for the causes and a cure for the disorder. The major areas of focus are:
Familial Trait (Inherited)
The predisposition for narcolepsy can be inherited because narcolepsy is a genetic disorder. Anyone diagnosed with narcolepsy should make information available to relatives and attempt to determine if other members are affected. Medical genealogy can be an important factor in identifying families affected by disorders of excessive daytime sleepiness (EDS). EDS appears more frequently in families than dose narcolepsy. For a first degree relative of a narcoleptic, the risk of developing some disorder of EDS is eight times greater than for the general population. The method by which the predisposition to inheriting narcolepsy is transmitted is unknown, but research is shedding some light on the subject.
Genetic Component
It appears there might be several genes that predispose a person to narcolepsy. A person with one or more of these genes might develop narcolepsy, whereas a person without any of the narcolepsy genes will nit develops it.
Environmental Factors
Particular factors, which may be different for each individual, have not been identified. In general, viruses, bacterias, chemicals, and even psychological stress are suspect.
Genetic Markers For Narcolepsy
Almost everyone who has narcolepsy has a specific blood type know as HLA-DR2. HLA stands for Human Leucocyte Antigen, a family of proteins critical to the immune system. The DR2 gene is a key component of the HLA system that controls the body’s immune defenses. Most people with DR2 have the closely related gene DQB1-0602 which is actually a better marker for narcolepsy.
Although an estimated 20-30% of the general population carries DR2 and/or DQB1-0602, only a tiny fraction will ever develop narcolepsy. Research theorizes that other unidentified genes and probably environment factors are needed in addition to the HLA factors to cause the onset of narcolepsy. The high correlation between the DR2 and the DQB1-0602 genes and narcolepsy suggests they code for a predisposition to the disorder. This association also suggests narcolepsy may be an autoimmune disorder.
Neurotransmitters
Million of neurons (brain cells) communicate with each other by means of chemicals called neurotransmitters. If any part of this complex system of sending and receiving messages is not functioning properly, the desired action will not take place.
Research studies suggest the brain may be hypersensitive to the neurotransmitter acetylcholine, which is important in the control of REM sleep. Other biochemical studies involve neurotransmitters called monoamines (dopamine, norepinephrine, and serotonin), which are important for the regulation of sleep, arousal, and alertness. Stimulants and antidepressants are through to work by enhancing the effects of these neurotransmitters. Research on monoamines and ho current narcolepsy drugs act on then may lead to the development of better treatments. Ultimately, however, the discovery of the genes that initially produce the acetylcholine and monoamine imbalances could result in finding a total cure for narcolepsy rather than a treatment that only reduces the symptoms of the disorder.
Autoimmune Hypothesis
Although there is no direct evidence to support the hypothesis, factors (such as the HLA-DR2 marker) suggest narcolepsy might be an autoimmune disorder. The body’s immune system provides protection against foreign objects. Occasionally, for some reason, it attacks its own tissue, usually causing signification damage. Hypothetically, in narcolepsy, the area in the brain that controls the sleep/wake processes could be damaged as a result of this kind of immune attack.