Narcolepsy, also known as Gelineau syndrome, is a rare disorder that has different types and degrees of presentation. It makes people fall asleep unexpectedly and affects approximately 0.1% of the world’s population.
The term narcolepsy was coined by Jean-Baptiste-Édouard Gélineau at the end of the 19th century. This researcher was the first to describe it in 1880. He gave it that name based on two Greek words, narke and lepsis, which together mean “numbness attack”.
Narcolepsy is a chronic neurological disorder that causes sleep rhythm disturbances. Its main symptom is strong drowsiness during the day and sudden drowsiness attacks that can’t be stopped.
Those with any type or degree of narcolepsy have great problems staying awake for several hours, regardless of the circumstances they find themselves in. For this reason, it significantly influences quality of life.
In some cases, this disorder appears with a sudden loss of muscle tone that’s defined, in medical terms, as cataplexy. This can occur due to an intense emotion and, ultimately, its appearance will define the type and degree of narcolepsy.
This disease has no cure and there’s no specific treatment as such. However, some medications help control these sudden sleep attacks. Likewise, lifestyle changes can prove helpful, as well as social and psychological support.
Characteristics of the disease
Here are the main characteristics of narcolepsy:
- Excessive daytime sleepiness. A decrease in alertness and concentration. This is usually the first symptom to manifest, and, after that, the sudden desire to sleep.
- Cataplexy. As we mentioned above, it doesn’t appear in all cases, nor with the same intensity.
- Sleep paralysis. This is the temporary inability to move or speak. In particular, it occurs when a person falls asleep or wakes up. They’re usually short episodes.
- Changes in REM sleep. REM sleep is the deepest. During it, there’s usually rapid eye movement. A person with narcolepsy can enter this stage at any time.
- Hallucinations. They’re called hypnagogic hallucinations if they occur before the person falls asleep or hypnopompic hallucinations if they occur when they wake up. They can be very vivid and terrifying.
People with narcolepsy may also suffer from other sleep disorders, such as obstructive sleep apnea, sleep fragmentation, and restless leg syndrome (RLS). Although it’s paradoxical, they can also suffer from insomnia.
Types and degrees of narcolepsy
According to the criteria of the DSM-5 (the fifth version of the Diagnostic and Statistical Manual of Mental Disorders), there are five types and degrees of narcolepsy, which are the following:
- Without cataplexy and with hypocretin deficiency. In this type of narcolepsy, there’s a deficiency of the hormone orexin or hypocretin. This is a protein that affects neuronal functioning. The main function of this protein is to control the sleep-wake cycle. This type doesn’t cause cataplexy episodes.
- With cataplexy and without hypocretin deficiency. In this case, there’s no hypocretin deficiency, but there is cataplexy. This is a sudden muscle weakness on both sides of the body. It’s the least understood symptom of this disorder and affects 5% of all cases.
- Autosomal dominant cerebellar ataxia (ADCA), deafness, and narcolepsy. This degree of narcolepsy is caused by a DNA mutation. Ataxia is a lack of motor coordination that affects voluntary movements and even hinders functions such as swallowing, speech, and sight. It’s late-onset and often leads to dementia as it progresses.
- Autosomal dominant cerebellar ataxia-deafness-narcolepsy, obesity, and type 2 diabetes. This is due to a mutation in the oligodendrocytes, a class of cells that affect myelin formation. The latter is a substance that increases the speed of nerve transmission and its deficiency affects mobility.
- Secondary to another medical condition. One of the types of narcolepsy appears as a consequence of another disease. For example, sarcoidosis or Whipple disease. Both destroy hypocretin-producing cells.
All degrees of narcolepsy require medical attention
Although there’s no cure for narcolepsy, treatments are currently available. They relieve most of the symptoms and allow the sufferer to lead an almost normal life.
Also, people who suffer from this condition can make lifestyle changes, such as taking scheduled naps to relieve sudden drowsiness. Likewise, they must be rigorous with their sleep hygiene. A person with narcolepsy needs psychological and social support.