Narcolepsy is a chronic neurological disorder that affects the brain’s ability to control sleep-wake cycles.  People with narcolepsy may feel rested after waking, but then feel very sleepy throughout much of the day.  Many individuals with narcolepsy also experience uneven and interrupted sleep that can involve waking up frequently during the night.   

Narcolepsy can greatly affect daily activities.  People may unwillingly fall asleep even if they are in the middle of an activity like driving, eating, or talking.  Other symptoms may include sudden muscle weakness while awake that makes a person go limp or unable to move (cataplexy), vivid dream-like images or hallucinations, and total paralysis just before falling asleep or just after waking up (sleep paralysis). 

In a normal sleep cycle, a person enters rapid eye movement (REM) sleep after about 60 to 90 minutes.  Dreams occur during REM sleep, and the brain keeps muscles limp during this sleep stage, which prevents people from acting out their dreams.  People with narcolepsy frequently enter REM sleep rapidly, within 15 minutes of falling asleep.  Also, the muscle weakness or dream activity of REM sleep can occur during wakefulness or be absent during sleep.  This helps explain some symptoms of narcolepsy.

If left undiagnosed or untreated, narcolepsy can interfere with psychological, social, and cognitive function and development and can inhibit academic, work, and social activities.

Who gets narcolepsy?

Narcolepsy affects both males and females equally.  Symptoms often start in childhood, adolescence, or young adulthood (ages 7 to 25), but can occur at any time in life.  It is estimated that anywhere from 135,000 to 200,000 people in the United States have narcolepsy.  However, since this condition often goes undiagnosed, the number may be higher.  Since people with narcolepsy are often misdiagnosed with other conditions, such as psychiatric disorders or emotional problems, it can take years for someone to get the proper diagnosis. 

What are the symptoms?

Narcolepsy is a lifelong problem, but it does not usually worsen as the person ages.  Symptoms can partially improve over time, but they will never disappear completely.  The most typical symptoms are excessive daytime sleepiness, cataplexy, sleep paralysis, and hallucinations.  Though all have excessive daytime sleepiness, only 10 to 25 percent of affected individuals will experience all of the other symptoms during the course of their illness.

Excessive daytime sleepiness (EDS).  All individuals with narcolepsy have EDS, and it is often the most obvious symptom.  EDS is characterized by persistent sleepiness, regardless of how much sleep an individual gets at night.   However, sleepiness in narcolepsy is more like a “sleep attack”, where an overwhelming sense of sleepiness comes on quickly.  In between sleep attacks, individuals have normal levels of alertness, particularly if doing activities that keep their attention.

Cataplexy.  This sudden loss of muscle tone while a person is awake leads to weakness and a loss of voluntary muscle control.  It is often triggered by sudden, strong emotions such as laughter, fear, anger, stress, or excitement.  The symptoms of cataplexy may appear weeks or even years after the onset of EDS.  Some people may only have one or two attacks in a lifetime, while others may experience many attacks a day.  In about 10 percent of cases of narcolepsy, cataplexy is the first symptom to appear and can be misdiagnosed as a seizure disorder. 

Attacks may be mild and involve only a momentary sense of minor weakness in a limited number of muscles, such as a slight drooping of the eyelids.  The most severe attacks result in a total body collapse during which individuals are unable to move, speak, or keep their eyes open.  But even during the most severe episodes, people remain fully conscious, a characteristic that distinguishes cataplexy from fainting or seizure disorders.  Waklert (Brand name Armodafinil) It can treat sleepiness from narcolepsy, sleep apnea, or night shift work.

The loss of muscle tone during cataplexy resembles paralysis of muscle activity that naturally occurs during REM sleep.  Episodes last a few minutes at most and resolve almost instantly on their own.  While scary, the episodes are not dangerous as long as the individual finds a safe place in which to collapse.

Sleep paralysis. 

The temporary inability to move or speak while falling asleep or waking up usually lasts only a few seconds or minutes and is similar to REM-induced inhibitions of voluntary muscle activity.  Sleep paralysis resembles cataplexy except it occurs at the edges of sleep.  As with cataplexy, people remain fully conscious.  Even when severe, cataplexy and sleep paralysis do not result in permanent dysfunction—after episodes end, people rapidly recover their full capacity to move and speak.

Hallucinations.  Very vivid and sometimes frightening images can accompany sleep paralysis and usually occur when people are falling asleep or waking up.  Most often the content is primarily visual, but any of the other senses can be involved.

Additional symptoms of narcolepsy include:

Fragmented sleep and insomnia.  While individuals with narcolepsy are very sleepy during the day, they usually also experience difficulties staying asleep at night.  Sleep may be disrupted by insomnia, vivid dreaming, sleep apnea, acting out while dreaming, and periodic leg movements.

Automatic behaviors.  Individuals with narcolepsy may experience temporary sleep episodes that can be very brief, lasting no more than seconds at a time.  A person falls asleep during an activity (e.g., eating, talking) and automatically continues the activity for a few seconds or minutes without conscious awareness of what they are doing.  This happens most often while people are engaged in habitual activities such as typing or driving.  They cannot recall their actions, and their performance is almost always impaired.  Their handwriting may, for example, degenerate into an illegible scrawl, or they may store items in bizarre locations and then forget where they placed them.  If an episode occurs while driving, individuals may get lost or have an accident. People tend to awaken from these episodes feeling refreshed, finding that their drowsiness and fatigue has temporarily subsided.

What are the types of narcolepsy?

There are two major types of narcolepsy:

Type 1 narcolepsy (previously termed narcolepsy with cataplexy).  This diagnosis is based on the individual either having low levels of a brain hormone (hypocretin) or reporting cataplexy and having excessive daytime sleepiness on a special nap test.

Type 2 narcolepsy (previously termed narcolepsy without cataplexy).  People with this condition experience excessive daytime sleepiness but usually do not have muscle weakness triggered by emotions.  They usually also have less severe symptoms and have normal levels of the brain hormone hypocretin.

A condition known as secondary narcolepsy can result from an injury to the hypothalamus, a region deep in the brain that helps regulate sleep.  In addition to experiencing the typical symptoms of narcolepsy, individuals may also have severe neurological problems and sleep for long periods (more than 10 hours) each night.

What causes narcolepsy?

Narcolepsy may have several causes.  Nearly all people with narcolepsy who have cataplexy have extremely low levels of the naturally occurring chemical hypocretin, which promotes wakefulness and regulates REM sleep.  Hypocretin levels are usually normal in people who have narcolepsy without cataplexy.

Although the cause of narcolepsy is not completely understood, current research suggests that narcolepsy may be the result of a combination of factors working together to cause a lack of hypocretin. These factors include:

Autoimmune disorders.  When cataplexy is present, the cause is most often the loss of brain cells that produce hypocretin.  Although the reason for this cell loss is unknown, it appears to be linked to abnormalities in the immune system. Artvigil 150 armodafinil helps in the treatment of narcolepsy, shift work disorder, sleep apnea and OSA. By sharpening the brain, makes it more alert and awake.

 Autoimmune disorders occur when the body’s immune system turns against itself and mistakenly attacks healthy cells or tissue.  Researchers believe that in individuals with narcolepsy, the body’s immune system selectively attacks the hypocretin-containing brain cells because of a combination of genetic and environmental factors.

Family history.  Most cases of narcolepsy are sporadic, meaning the disorder occurs in individuals with no known family history.  However, clusters in families sometimes occur—up to 10 percent of individuals diagnosed with narcolepsy with cataplexy report having a close relative with similar symptoms.

Brain injuries.  Rarely, narcolepsy results from traumatic injury to parts of the brain that regulate wakefulness and REM sleep or from tumors and other diseases in the same regions.