Narcolepsy Fact Sheet | National Institute of Neurological Disorders and Stroke National Institute of Neurological Disorders and Stroke Where can I get more information? What is narcolepsy? Narcolepsy is a chronic brain disorder that involves poor control of sleep-wake cycles. People with narcolepsy experience periods of extreme daytime sleepiness and sudden, irresistible bouts of sleep that can strike at any time. These “sleep attacks” usually last a few seconds to several minutes. Narcolepsy can greatly affect daily activities. People may unwillingly fall asleep while at work or at school, when having a conversation, playing a game, eating a meal, or, most dangerously, when driving or operating other types of machinery. In addition to daytime sleepiness, other major symptoms may include cataplexy (a sudden loss of voluntary muscle tone while awake that makes a person go limp or unable to move), vivid dream-like images or hallucinations, as well as total paralysis just before falling asleep or just after waking-up. Contrary to common beliefs, people with narcolepsy do not spend a substantially greater proportion of their time asleep during a 24-hour period than do normal sleepers.

In addition to daytime drowsiness and uncontrollable sleep episodes, most individuals also experience poor sleep quality that can involve frequent waking during nighttime sleep, and other sleep disorders. For most adults, a normal night's sleep lasts about 8 hours and is composed of four to six separate sleep cycles. A sleep cycle is defined by a segment of non-rapid eye movement (NREM) sleep followed by a period of rapid eye movement (REM) sleep. The NREM segment can be further divided into increasingly deeper stages of sleep according to the size and frequency of brain waves. REM sleep is accompanied by bursts of rapid eye movement along with sharply heightened brain activity and temporary paralysis of the muscles that control posture and body movement. When subjects are awakened, they report that they were "having a dream" more often if they had been in REM sleep than if they had been in NREM sleep. Transitions from NREM to REM sleep are controlled by interactions among groups of neurons (nerve cells) located in different parts of the brain. For normal sleepers a typical sleep cycle is about 100 to 110 minutes long, beginning with NREM sleep and transitioning to REM sleep after 80 to 100 minutes.

People with narcolepsy frequently enter REM sleep within a few minutes of falling asleep. Who gets narcolepsy? Narcolepsy affects both males and female equally and appears throughout the world. Symptoms often start in childhood or adolescence, but can occur later in life. The condition is life-long. Narcolepsy is not rare, but it is an underrecognized and underdiagnosed condition. Narcolepsy with cataplexy is estimated to affect about one in every 3,000 Americans. More cases without cataplexy are also likely to exist. What are the symptoms? People with narcolepsy experience various types of day- and nighttime sleep problems that are associated with REM sleep disturbances that tend to begin subtly and may change dramatically over time. The most common major symptom, other than excessive daytime sleepiness (EDS), is cataplexy, which occurs in about 70 percent of all people with narcolepsy. Sleep paralysis and hallucinations are somewhat less common. Only 10 to 25 percent of affected individuals, however, display all four of these major symptoms during the course of their illness.

Excessive daytime sleepiness (EDS) EDS, the symptom most consistently experienced by almost all individuals with narcolepsy, is usually the first to become clinically apparent. Generally, EDS interferes with normal activities on a daily basis, whether or not individuals had sufficient sleep at night. People with EDS describe it as a persistent sense of mental cloudiness, a lack of energy, a depressed mood, or extreme exhaustion. Some people experience memory lapses, and many have great difficulty maintaining their concentration while at school, work, or home. People tend to awaken from such unavoidable sleeps feeling refreshed and finding that their drowsiness and fatigue subsides for an hour or two. Involuntary sleep episodes are sometimes very brief, lasting no more than seconds at a time. As many as 40 percent of people with narcolepsy are prone to automatic behavior during such “microsleeps.” Automatic behavior involves performing a task during a short period of sleep but without any apparent interruption. During these episodes, people are usually engaged in habitual, essentially "second nature" activities such as taking notes in class, 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. EDS, the most common of all narcoleptic symptoms, can be the result of a wide range of medical conditions, including other sleep disorders such as sleep apnea, various viral or bacterial infections, mood disorders such as depression, and chronic illnesses such as anemia, congestive heart failure, and rheumatoid arthritis that disrupt normal sleep patterns. Some medications can also lead to EDS, as can consumption of caffeine, alcohol, and nicotine. Finally, sleep deprivation has become one of the most common causes of EDS among Americans. Cataplexy Cataplexy is a sudden loss of muscle tone while the person is awake that leads to feelings of weakness and a loss of voluntary muscle control. Attacks can occur at any time during the waking period, with individuals usually experiencing their first episodes several weeks or months after the onset of EDS. But in about 10 percent of all cases, cataplexy is the first symptom to appear and can be misdiagnosed as a seizure disorder.

Cataplectic attacks vary in duration and severity. The loss of muscle tone can be barely perceptible, involving no more than a momentary sense of slight weakness in a limited number of muscles, such as mild drooping of the eyelids. The most severe attacks result in a complete loss of tone in all voluntary muscles, leading to physical 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 seizure disorders. Although cataplexy can occur spontaneously, it is more often triggered by sudden, strong emotions such as fear, anger, stress, excitement, or humor. Laughter is reportedly the most common trigger. The loss of muscle tone during a cataplectic episode resembles the interruption of muscle activity that naturally occurs during REM sleep. A group of neurons in the brain stem halts activity during REM sleep, inhibiting muscle movement. Using an animal model, scientists have learned that this same group of neurons becomes inactive during cataplectic attacks, a discovery that provides a clue to at least one of the neurological abnormalities contributing to human narcoleptic symptoms.

Sleep paralysis The temporary inability to move or speak while falling asleep or waking is similar to REM-induced inhibitions of voluntary muscle activity. This natural inhibition usually goes unnoticed by people who experience normal sleep because it occurs only when they are fully asleep and entering the REM stage at the appropriate time in the sleep cycle. The attacks usually last a few seconds or minutes. Experiencing sleep paralysis resembles undergoing a cataplectic attack affecting the entire body. 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 Hallucinations can accompany sleep paralysis and occur when people are falling asleep, waking, or during sleep. Referred to as hypnagogic hallucinations when occurring during sleep onset and as hypnopompic hallucinations when occurring during waking, these images are unusually vivid, seem real, and can be frightening. Most often, the content is primarily visual, but any of the other senses can be involved. Disrupted nocturnal sleep While individuals with narcolepsy have no difficulties falling asleep at night, most experience difficulties staying asleep.

Sleep may be disrupted by insomnia, vivid dreaming, sleep talking, acting out while dreaming, and periodic leg movements. Obesity After developing narcolepsy, many individuals suddenly gain weight, a side effect that can be prevented by active treatment. When do symptoms appear? In most cases, symptoms first appear when people are between the ages of 7 and 25. In rare cases, however, narcolepsy may appear at younger age or in older adults. If left undiagnosed and untreated, early onset narcolepsy can interfere with psychological, social, and cognitive function and development and can undermine academic and social activities. What causes narcolepsy? Narcolepsy may have several causes. Most people with narcolepsy have low levels of the neurotransmitter hypocretin, which promotes wakefulness. Neurotransmitters are chemicals that neurons produce to communicate with each other and to regulate biological processes. Most cases of narcolepsy are sporadic, meaning the disorder occurs in individuals with no known family history of the disorder. But clusters in families sometimes occur—up to 10 percent of individuals diagnosed with narcolepsy with cataplexy report having a close relative with the same symptoms.

In extremely rare cases, narcolepsy is caused by a genetic defect that prevents normal production of hypocretin molecules. While close relatives of people with narcolepsy have a statistically higher risk of developing the disorder than do members of the general population, that risk remains low when compared to diseases that are purely genetic in origin. When cataplexy is present, the cause is most often the discrete loss of brain cells that produce hypocretin. Although the reason for such cell loss remains unknown, it appears to be autoimmune in nature (an autoimmune disorder is when the body’s immune system mistakenly attacks healthy cells or tissue). That is, the body’s immune system selectively attacks hypocretin-containing brain cells. Other factors appear to play important roles in the development of narcolepsy. Some rare cases are known to result from traumatic injuries to parts of the brain involved in REM sleep or from tumor growth and other disease processes in the same regions. Infections, exposure to toxins, dietary factors, stress, hormonal changes such as those occurring during puberty or menopause, and alterations in a person's sleep schedule are just a few of the many factors that may exert direct or indirect effects on the brain, thereby possibly contributing to disease development. How is narcolepsy diagnosed?

A clinical examination and exhaustive medical history are essential for diagnosis and treatment. Your doctor may ask you to keep a sleep journal noting the times of sleep and symptoms over a one-to-two-week period. Although none of the major symptoms is exclusive to narcolepsy, cataplexy is the most specific symptom and is rarely present outside of narcolepsy. A physical exam can rule out or identify a condition that may be causing the symptoms. A battery of specialized tests, which can be performed in a sleep disorders clinic, is usually required before a diagnosis can be confirmed. Two tests in particular are essential in confirming a diagnosis of narcolepsy: the polysomnogram (PSG) and the multiple sleep latency test (MSLT). The PSG is an overnight test that takes continuous multiple measurements while the individual is asleep to document abnormalities in the sleep cycle. It records heart and respiratory rates, electrical activity in the brain using electroencephalography, and nerve activity in muscles through electromyography. A PSG can help reveal whether REM sleep occurs at abnormal times in the sleep cycle and can rule out the possibility that an individual's symptoms result from another condition.

The MSLT is performed during the day to measure a person's tendency to fall asleep and to determine whether isolated elements of REM sleep intrude at inappropriate times during the waking hours. The sleep latency test measures the amount of time it takes for a person to fall asleep. As part of the test, an individual is asked to take four or five short naps usually scheduled 2 hours apart over the course of a day. Because sleep latency periods are normally 12 minutes or longer, a latency period of 8 minutes or less suggests a disorder of excessive daytime sleepiness. However, a sleep latency of 8 minutes or less can be due to many conditions other than narcolepsy. The MSLT also measures heart and respiratory rates, records nerve activity in muscles, and pinpoints the occurrence of abnormally timed REM episodes through EEG recordings. If a person enters REM sleep either at the beginning or within a few minutes of sleep onset during at least two of the scheduled naps, this is considered an indication of narcolepsy. Other reasons for REM sleep on the MSLT must be ruled out, such as the effects of medication and disrupted sleep from sleep apnea or an irregular work-rest schedule.

In some cases, human leukocyte antigen (HLA) typing (a marker of viral infection) may be helpful. Most HLA-associated disorders are autoimmune in nature. Certain alleles (genetic information found on a specific location on specific chromosomes) located on chromosome 6 are strongly associated with narcolepsy-cataplexy. To definitively identify a lack of hypocretin as the cause of narcolepsy, a sample of the cerebrospinal fluid (CSF) is removed by using a lumbar puncture and the level of hypocretin-1 is measured. When no other serious medical condition is present, low CSF hypocretin-1 can establish hypocretin deficiency as the cause of narcolepsy. When cataplexy is not present, diagnosis must be made after excluding other possible causes of daytime sleepiness and fatigue, along with a positive MSLT. What treatments are available? Narcolepsy cannot yet be cured, but some of the symptoms can be treated with medicines and lifestyle changes. When cataplexy is present, the loss of hypocretin is believed to be irreversible and life-long. But EDS and cataplexy can be controlled in most individuals with drug treatment.

Modafinil and sodium oxybate are two drugs that have been approved by the U.S. Food and Drug Administration for the treatment of narcolepsy. Doctors prescribe central nervous system alerting agents such as modafinil and amphetamine-like stimulants such as methylphenidate to alleviate EDS and reduce the incidence of sleep attacks. For most people these medications are generally quite effective at reducing daytime drowsiness and improving levels of alertness. However, use of these medications may be associated with several undesirable side effects and must be carefully monitored. Common side effects include irritability and nervousness, shakiness, disturbances in heart rhythm, stomach upset, nighttime sleep disruption, and anorexia. Individuals may also develop tolerance with long-term use, leading to the need for increased dosages to maintain effectiveness. In addition, doctors should be careful when prescribing these drugs and people should be careful using them because the potential for abuse is high with any amphetamine.

Two classes of antidepressant drugs have proved effective in controlling cataplexy in many individuals: tricyclics (including imipramine, desipramine, clomipramine, and protriptyline) and selective serotonin and noradrenergic reuptake inhibitors (including venlafaxine, fluoxetine and atomoxetine). In general, antidepressants produce fewer adverse effects than do amphetamines. But troublesome side effects still occur in some individuals, including impotence, high blood pressure, and heart rhythm irregularities. In addition to central nervous system alerting agents and antidepressants, sodium oxybate or gamma hydroxybutyrate, also known as GHB or Xyrem®, can be used to treat narcolepsy. Sodium oxybate is a strong sedative that must be taken during the night. Sodium oxybate induces sleep and reduces the symptoms of daytime sleepiness and cataplexy. Due to safety concerns associated with the use of this drug, the distribution of sodium oxybate is tightly restricted. What behavioral strategies help people cope with symptoms? Currently available medications do not enable all people with narcolepsy to consistently maintain a fully normal state of alertness.

Drug therapy should accompany various behavioral strategies according to the needs of the affected individual. Many individuals take short, regularly scheduled naps at times when they tend to feel sleepiest. Improving the quality of nighttime sleep can combat EDS and help relieve persistent feelings of fatigue. Among the most important common-sense measures people can take to enhance sleep quality are: maintain a regular sleep schedule—go to bed and wake up at the same time every day avoid alcohol and caffeine-containing beverages for several hours before bedtime avoid large, heavy meals just before bedtime avoid smoking, especially at night maintain a comfortable, adequately warmed bedroom environment, and engage in relaxing activities such as a warm bath before bedtime. Exercising for at least 20 minutes per day at least 4 or 5 hours before bedtime also improves sleep quality and can help people with narcolepsy avoid gaining excess weight. Safety precautions, particularly when driving, are particularly important for all persons with narcolepsy. EDS and cataplexy can lead to serious injury or death if left uncontrolled. Suddenly falling asleep or losing muscle control can transform actions that are ordinarily safe, such as walking down a long flight of stairs, into hazards.

People with untreated narcoleptic symptoms are involved in automobile accidents roughly 10 times more frequently than the general population. However, accident rates are normal among individuals who have received appropriate medication. Support groups frequently prove extremely beneficial because people with narcolepsy may become socially isolated due to embarrassment about or misunderstandings related to their symptoms. Many people also try to avoid strong emotions, since humor, excitement, and other intense feelings can trigger cataplectic attacks. Support groups also provide individuals with a network of social contacts who can offer practical help and emotional support. The Americans with Disabilities Act requires employers to provide reasonable accommodations for all employees with disabilities. Adults can often negotiate with employers to modify their work schedules so they can take naps when necessary and perform their most demanding tasks when they are most alert. Similarly, children and adolescents with narcolepsy may be able to work with school administrators regarding special needs, including medication requirements during the school day, and to modify class schedules. What is the state of the science involving narcolepsy? During the past decade, scientists have made considerable progress in understanding narcolepsy-cataplexy pathogenesis and in identifying genes strongly associated with the disorder.

The majority of people diagnosed with narcolepsy and cataplexy are known to have a specific HLA gene variant called DQB1*0602. They also frequently have specific alleles at a gene called the T- cell receptor alpha (TCRA), a protein on T cells that recognize HLA proteins. However, some people with narcolepsy-cataplexy do not have the variant genes, while many people in the general population without narcolepsy do possess these variant genes. Specific variations in HLA and TCRA genes increase an individual's predisposition to develop the disorders—possibly through a yet-undiscovered route involving changes in immune-system function—when other causative factors are present. Many other genes besides those making up the HLA complex and the T-cell receptor may contribute to the development of narcolepsy. Groups of neurons in several parts of the brain stem and the central brain, including the thalamus and hypothalamus, interact to control sleep. Large numbers of genes on different chromosomes control these neurons' activities, any of which could contribute to the development of the disease.

Scientists studying narcolepsy in dogs have identified a mutation that appears to cause the disorder in Dobermans, Labradors, and Dachshunds. This mutated gene disrupts the ability to receive the signal from hypocretins (also known as orexins) that are produced by neurons located in the hypothalamus. The neurons that produce hypocretins are active during wakefulness, and research suggests that they keep the brain systems needed for wakefulness from shutting down unexpectedly. Mice born without functioning hypocretin genes develop symptoms of narcolepsy. Except in rare cases, narcolepsy in humans is not associated with mutations of the hypocretin gene. However, scientists have found that brains from humans with narcolepsy often contain greatly reduced numbers of hypocretin-producing neurons. It is believed that certain HLA and TCR subtypes increase susceptibility to an immune attack on hypocretin neurons in the hypothalamus, leading to degeneration of these important cells. Other factors also may interfere with proper functioning of this system. The hypocretins regulate appetite and feeding behavior in addition to controlling sleep.

Therefore, the loss of hypocretin-producing neurons may explain not only how narcolepsy develops in some people, but also why people with narcolepsy have higher rates of obesity compared to the general population. Narcolepsy onset follows a seasonal pattern of higher rates in spring and early summer, following winter upper airway infection season. When studied close to disease onset, individuals with narcolepsy have high levels of antibodies to a marker called ASO, indicating response to a recent bacterial infection such as strep throat. In addition, there is growing evidence that exposure to H1N1 virus (also called swine flu), or a special form of H1N1 vaccine (administered in Europe) can act as a rare trigger for the disease. It is not yet known if these infectious agents are direct triggers for the disease, or whether they increase likelihood of disease indirectly. What research is being done? Within the Federal government, the National Institute of Neurological Disorders and Stroke (NINDS), a component of the National Institutes of Health (NIH), has primary responsibility for sponsoring research on neurological disorders. As part of its mission, the NINDS supports research on narcolepsy and other sleep disorders through grants to medical institutions across the country.

Within the National Heart, Lung, and Blood Institute, also a component of the NIH, the National Center on Sleep Disorders Research (NCSDR) coordinates Federal government sleep research activities, promotes doctoral and postdoctoral training programs, and educates the public and health care professionals about sleep disorders. For more information, visit the NCSDR website at . NINDS-sponsored researchers are conducting studies devoted to further clarifying the wide range of genetic factors—both HLA genes and non-HLA genes—that may cause narcolepsy. Other scientists are conducting investigations using animal models to identify neurotransmitters other than the hypocretins that may contribute to disease development. A greater understanding of the complex genetic and biochemical bases of narcolepsy will eventually lead to the formulation of new therapies to control symptoms and may lead to a cure. Researchers are also investigating the modes of action of wake-promoting compounds to widen the range of available therapeutic options. Abnormal immunological processes may be an important element in the cause of narcolepsy. NINDS-sponsored scientists have demonstrated the presence of unusual, possibly pathological, forms of immunological activity in narcolepsy. Further, strep throat is now suggested to be involved as a trigger in some predisposed individuals.

These researchers are now investigating whether drugs that suppress immunological processes may interrupt the development of narcolepsy. Finally, the NINDS continues to support investigations into the basic biology of sleep, including the brain mechanisms involved in generating and regulating REM sleep. A more comprehensive understanding of the complex biology of sleep will undoubtedly further clarify the pathological processes that underlie narcolepsy and other sleep disorders. How can I help research? The NINDS contributes to the support of the Human Brain and Spinal Fluid Resource Center in Los Angeles. This bank supplies investigators around the world with tissue from individuals with neurological and other disorders. Tissue from individuals with narcolepsy is needed to enable scientists to study this disorder more intensely. Prospective donors may contact: Human Brain and Spinal Fluid Resource Center Building 212 West Los Angeles Healthcare Center 11301 Wilshire Blvd. (127A) Office of Communications and Public Liaison National Institute of Neurological Disorders and Stroke National Institutes of Health Bethesda, MD 20892 NINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency.

Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history. All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated. Narcolepsy: Symptoms and Treatment of Narcolepsy Narcolepsy Symptoms and Treatment of Narcolepsy The sudden sleep attacks and loss of muscle control caused by narcolepsy can be frightening, embarrassing, and cause serious disruption in your life. It can endanger your physical safety, impact your relationships, create memory and concentration problems, and take a toll on your self-esteem and mental health. Ordinary daily activities such as driving, cooking, or even walking can become dangerous, and extreme daytime sleepiness can put a strain on work, school and intimate relationships. But there is hope. While there is not yet a cure for narcolepsy, there are plenty of things you can do to reduce the symptoms, improve your alertness, and enjoy a full and active life.

What you can do Recognize the signs and symptoms of narcolepsy Use the Epworth scale to test for narcolepsy Move frequently in your daily life and exercise regularly Learn to recognize and manage intense emotions Avoid activities that might be dangerous if you have narcolepsy Understand the role of medication in narcolepsy treatment What is narcolepsy? Narcolepsy is a chronic neurological disorder affecting the part of your brain that regulates sleep. Narcolepsy is more common than you probably realize—affecting about 1 in 2,000 people—and can cause you to experience excessive daytime sleepiness and a sudden loss of muscle control (called cataplexy), often triggered by strong emotions. As a result, you may fall asleep during normal daytime activities such as working, studying, or driving. While these episodes can be brief, lasting just a few seconds, it can make many normal activities dangerous and disrupt your normal daily life. With a combination of lifestyle changes, self-help strategies, counseling, and medical support, however, you can manage narcolepsy symptoms and regain control of your life.

The effects of narcolepsy Physical well-being and safety - Many ordinary daily activities, such as cooking or walking, can become very dangerous if you fall asleep or lose muscle control unexpectedly Mental health - Narcolepsy can disrupt your life to the extent that it may lead to depression and anxiety. Social and professional relationships - Unfortunately, sudden sleep episodes are often found humorous to those not familiar with narcolepsy. Some people may assume that you are lazy, rude, or even faking the sudden sleep episodes. Intimate relationships - Your personal relationships, especially spousal relationships, can often suffer as a result of narcolepsy. Extreme sleepiness may also cause low sex drive and impotence. Memory and attention - Narcolepsy may cause you to have problems remembering things and concentrating, creating more disruption to your daily activities. Signs and symptoms of narcolepsy Most people with narcolepsy experience their first symptoms between the ages of 10 and 25, and they can be especially debilitating for children or young people still facing the challenges of school, college, or the early stages of their careers.

While symptoms can vary greatly from one person to another, the main narcolepsy symptoms are excessive daytime sleepiness (with or without sudden sleep episodes) and abnormal REM sleep. Other symptoms of narcolepsy may be related to your abnormal REM sleep, including hallucinations, sleep paralysis, and cataplexy (sudden loss of muscle control). Two of the most common narcolepsy symptoms—excessive daytime sleepiness and cataplexy—are often connected to your emotional state. You may tend to exhibit these symptoms when you experience intense emotions, such as laughter, sadness, surprise, or frustration. Common narcolepsy symptoms include: Cataplexy (loss of muscle control). Often, narcolepsy may cause you to have sudden loss of muscle control while awake, usually triggered by strong emotions, such as laughing or crying. Hallucinations. Some people with narcolepsy experience vivid, sometimes frightening, visual or auditory sensations while falling asleep or upon awakening. Sleep paralysis. You may be unable to move or talk at the beginning or end of sleep. Microsleep is a very brief sleep episode during which you continue to function (talk, put things away, etc.) and then awaken with no memory of the activities. Nighttime wakefulness.

If you suffer from narcolepsy, you may have periods of wakefulness at night with hot flashes, elevated heart rate, and sometimes intense alertness. Rapid entry to REM sleep. Narcoleptics have unique sleep cycles where he or she may enter the REM or dream phase of sleep right after falling alseep, whereas most people take about 90 minutes to enter REM. Therefore, you'll experience the characteristics of REM sleep (vivid dreams and muscle paralysis) at the beginning of sleep, even if that sleep is during the day. The causes of narcolepsy While researchers continue to seek out the root cause of narcolepsy, the general consensus is that your genetics, accompanied by an environmental trigger of some sort—a virus, for example—may affect your brain chemicals and cause narcolepsy. Scientists have discovered that people with narcolepsy are lacking in hypocretin (also called orexin), a chemical in the brain that activates arousal and regulates sleep. Narcoleptics generally do not have as many Hcrt cells (neurons that secrete hypocretin), inhibiting his or her ability to fully control alertness, which accounts for his or her tendency to fall asleep.

Scientists are working on developing treatments to supplement hypocretin levels to reduce narcolepsy symptoms. Diagnosing narcolepsy Narcolepsy can often be either mis- or undiagnosed. People with narcolepsy often wait to consult a doctor because the most common (and sometimes the only) symptom is excessive daytime sleepiness, a symptom that could be indicative of many conditions. Additionally, narcolepsy symptoms are often falsely attributed to other sleep disorders or medical conditions (such as depression or epilepsy). As the only unique symptom of narcolepsy is cataplexy (sudden loss of muscle control), diagnosis of the condition can take a long time. If you suspect you have narcolepsy, be sure to speak with your doctor about ALL of the symptoms you are experiencing. Along with your list of symptoms, physicians and sleep specialists use the following methods to diagnose narcolepsy: Nocturnal polysomnogram – This overnight test measures the electrical activity of your brain and heart, and the movement of your muscles and eyes. Multiple sleep latency test (MSLT) – This test measures how long it takes for you to fall asleep during the day.

Spinal fluid analysis – The lack of hypocretin in the cerebrospinal fluid may be a marker for narcolepsy. Examining spinal fluid is a new diagnostic test for narcolepsy. Epworth Sleepiness Scale to test for narcolepsy The Epworth Sleepiness Scale measures daytime sleepiness. Use the following scale to choose the most appropriate number for each situation: 0 = would never doze or sleep 1 = slight chance of dozing or sleeping 2 = moderate chance of dozing or sleeping 3 = high chance of dozing or sleeping Situation Please answer all the questions Score: Interpreting the score: A total score of 10 or more is considered sleepy. A score of 18 or more is very sleepy. This questionnaire is not intended to replace professional diagnosis. Source: University of Maryland Medical Center Narcolepsy treatment Although no cure yet exists for narcolepsy, a combination of treatments can help control your narcolepsy symptoms and enable you to enjoy many normal activities. The treatment that works best for you will vary according to your specific narcolepsy symptoms, but will likely include a combination of counseling, medication, and lifestyle changes.

Narcolepsy treatment: counseling and support groups It’s very common for those with narcolepsy to suffer from depression . Many symptoms of narcolepsy—particularly sleep attacks and cataplexy—can cause great embarrassment and wreak havoc on your ability to live a normal life. These episodes can be frightening, and you may become depressed because of the sudden lack of control. Fear of falling asleep or of sudden collapse forces some people to become reclusive and withdrawn. Reaching out to a psychologist, counselor, or narcolepsy support group can help you cope with the effects of the disorder. Reaching out may seem overwhelming at first, but being with others who face the same problems can help reduce your sense of isolation and remove any stigma you may feel. It can also be inspiring to share experiences and learn how others have coped with his or her symptoms of narcolepsy. For help finding a therapist or narcolepsy support group, see the Resources section below. Lifestyle changes to ease the symptoms of narcolepsy Making healthy lifestyle changes can help you manage narcolepsy symptoms, in conjunction with counseling and support, and any recommendations from your doctor.

Daytime habits—such as exercise, diet, and how you manage stress—play a large role in helping you maintain a healthy sleep-wake cycle. It’s important to follow a regular sleep schedule, a relaxing bedtime routine, and take practical steps to counter the effects of narcolepsy during the day. Combining the various self-help treatments can help to not only improve your daytime alertness but also help reduce the symptoms of narcolepsy. Schedule your sleep periods - Take a few brief, scheduled naps during the daytime (10-15 minutes each). Try to get a good night's sleep during the same hours each night. Planned naps can prevent unplanned lapses into sleep. Avoid caffeine, alcohol, and nicotine - These substances interfere with sleep when you need it. Avoid over-the-counter drugs that cause drowsiness - Some allergy and cold medications can cause drowsiness, so they should be avoided. Involve your employers, coworkers, and friends - Alert others so they can help when needed. Carry a tape recorder - Record important conversations and meetings, in case you fall asleep.

Break up larger tasks into small pieces - Focus on one small thing at a time Exercise on a regular basis - Exercise can make you feel more awake during the day and stimulate sleep at night. For example, take several short walks during the day. Avoid activities that would be dangerous if you had a sudden sleep attack - If possible, don't drive, climb ladders, or use dangerous machinery. Taking a nap before driving may help you manage any possible sleepiness. Wear a medical alert bracelet or necklace - A bracelet or necklace will alert others if you suddenly fall asleep or become unable to move or speak. Eat a healthy diet - Aim for a diet rich in whole grains, vegetables, fruits, low fat dairy, and lean sources of protein. Eat light or vegetarian meals during the day and avoid heavy meals before important activities. Relax and manage emotions - Narcolepsy symptoms can be triggered by intense emotions, so you may benefit from practicing relaxation techniques, such as breathing exercises, yoga, or massage. Medications for the treatment of narcolepsy Medication can be helpful in treating the major symptoms of narcolepsy: sleepiness and cataplexy. Commonly prescribed drugs for narcolepsy are stimulants, antidepressants, and sodium oxybate.

All medications have side effects so be sure to check with your doctor first. Even if your narcolepsy symptoms require the use of prescription medication, experts recommend combining a drug regimen with lifestyle changes and counseling or therapy. Common medications include: Stimulants. Stimulants are the mainstay of drug treatment for narcolepsy. These include modafinil (Provigil), a stimulant used during the day to promote wakefulness and alertness. Side effects of modafinil may include headache, nausea, dry mouth, and diarrhea. Psychiatric side effects, such as anxiety, mania, hallucinations, and suicidal thinking have also been reported, so the drug should be avoided if you have a history of depression, mania, or psychosis. Sodium oxybate (Xyrem). This strong drug may be prescribed if you have severe cataplexy. Sodium oxybate is also known as GHB, or the "date rape drug," but is considered safe for treating narcolepsy when used responsibly to promote sound sleep, diminish daytime sleepiness, and reduce incidences of cataplexy. However, the side effects can be serious and may include nausea, bed-wetting, and worsening of sleepwalking.

Too high a dose can even lead to difficulty breathing, coma, and death. Antidepressants. Selective serotonin reuptake inhibitors (SSRIs) used to treat depression may also be used to help suppress REM sleep, and alleviate symptoms of cataplexy, hallucinations, and sleep paralysis. These include fluoxetine (Prozac), sertaline (Zoloft), and newer antidepressants such as venlafazine (Effexor). While the most common side effects of antidepressants include decreased sexual desire, digestive problems, restlessness, headache, and insomnia, there can also be dangerous side effects. Antidepressant drug risk factors Antidepressants can produce unpleasant or dangerous side effects, including an increased risk of suicide. The risk factors are higher for: People with bipolar disorder. Antidepressants can trigger mania or cause rapid cycling between depression and mania. (Note that many people with bipolar disorder are undiagnosed). Teens, adolescents, and young adults. The U.S. Food and Drug Administration require that all depression medications include a warning label about the increased risk of suicide in children and young adults. People over 65. SSRI medications may increase the risk for falls, fractures, and bone loss in older adults.

Pregnant women. The use of SSRIs late in pregnancy may lead to short-term withdrawal symptoms in newborns after delivery. Typical symptoms include tremors, restlessness, milk respiratory problems, and a weak cry. Related HelpGuide articles Narcolepsy Guide: Causes, Symptoms and Treatment Options Q & A What Is It? Narcolepsy is a disorder that causes sudden episodes of deep sleep. These episodes can occur often and at inappropriate times, for example while a person is talking, eating or driving. Although sleep episodes can happen at any time, they may be more frequent during periods of inactivity or monotonous, repetitive activity. Narcolepsy usually appears between ages 15 and 30, but the condition can appear earlier or later. Once it appears, narcolepsy is present for life. Men and women are affected equally. About 60% of people with diagnosed narcolepsy have the combination of marked daytime sleepiness and sudden episodes of muscle weakness (called cataplexy). The muscle weakness can be so severe that a person with narcolepsy will collapse to the floor, but not become unconscious.

This type of narcolepsy is associated with a shortage of a brain-stimulating protein called orexin (also known as hypocretin). The cause of other types of narcolepsy is unknown. A genetic (inherited) predisposition appears to play a role. People with narcolepsy don't require extra hours of sleep, but they do need daytime naps because they have difficulty staying awake for long periods. During the night, healthy people normally progress through several stages of sleep before entering or leaving the state of sleep called rapid eye movement (REM). During REM sleep, your brain waves resemble those of an awake person, visual dreams occur and muscle tone is slack. In narcolepsy, the brain-wave pattern can skip some or all of the other sleep stages, causing the person to move from the awake state immediately to REM sleep, or to awaken directly from the REM sleep stage. Symptoms The earliest symptom of narcolepsy is usually daytime sleepiness, which may be extreme. However, it may take years to recognize the disorder because other, more common causes of daytime sleepiness often are blamed for the symptoms. Narcolepsy has four main symptoms.

It is common for people with narcolepsy to have more than one symptom, but it is rare for a person with the disease to experience all four: Excessive daytime sleepiness — This is always present and is usually the most prominent symptom. Cataplexy — This is the sudden, temporary loss of muscle tone, which causes paralysis of the head or body while the person remains conscious. It can last a few seconds or several minutes. Mild attacks can cause slurred or stuttering speech, drooping eyelids or hand weakness that causes the person to drop objects. Severe attacks can cause the knees to buckle, leading to collapse. Typically, cataplexy is brought on by laughter, excitement or anger. The sudden relaxing of muscle tone is probably the result of the brain abruptly entering REM sleep. Sleep paralysis — This is the temporary inability to move while falling asleep or awakening. It lasts no more than several minutes. Like cataplexy, sleep paralysis probably is related to insufficient separation between REM sleep and the awake state. Hypnagogic hallucinations — These are dreamlike images that are seen during the awake state instead of during sleep. These often-frightening visions are seen just as the person is falling asleep or waking up.

They tend to occur in people who also have sleep paralysis. Symptoms usually begin during adolescence or young adulthood. People with narcolepsy complain of fatigue, experience impaired performance at work and school, and may have difficulty in social relationships. Excessive daytime sleepiness can be disabling and may greatly diminish a person's quality of life. Memory lapses and visual disturbances may be particularly upsetting. More than 50% of people with narcolepsy experience periods of memory lapse or blackouts caused by very short periods of sleep called micro-sleeps. Micro-sleeps are not unique to people with narcolepsy, and they can be experienced by anyone who is severely sleep deprived. They are periods of sleep that last only a few seconds, and usually are not noticed. During such episodes, a person may get lost while walking or driving, write or speak nonsense, misplace objects, or bump into things. Later in the course of narcolepsy, a person also can develop insomnia (difficulty sleeping) during normal sleeping hours. Diagnosis To diagnose narcolepsy, your doctor will ask you about your history of typical episodes and will have you undergo an overnight sleep study.

The sleep study checks for other explanations that could account for daytime sleepiness, such as sleep apnea or other causes of sleep interruptions. The sleep test measures brain waves, eye movements, muscle activity, heartbeat, blood oxygen levels and breathing. A specific study called a multiple sleep latency test is a necessary part of the evaluation for narcolepsy. This test must be done after the person has had an adequate night's sleep. A multiple sleep latency test consists of four 20-minute opportunities to nap, which are offered every two hours throughout the day. Patients with narcolepsy fall asleep in approximately five minutes or less, and move into REM sleep during at least two of the four naps. Normal well-rested sleepers take about 12 to 14 minutes to fall asleep for a daytime nap, and don't fall directly into REM sleep. Expected Duration Narcolepsy cannot be cured and does not go away. In most cases, symptoms can be diminished with medications, regularly scheduled naps and good sleep habits. Prevention There is no way to prevent narcolepsy. For people who have the condition, avoiding conditions that bring on narcolepsy episodes may help to reduce their frequency.

If you have narcolepsy and your symptoms are not controlled with medicines, you should never smoke because you could fall asleep with a lit cigarette, and you should never drive. Treatment The main symptom of narcolepsy, excessive daytime sleepiness, can be partially relieved with stimulants such as modafinil ( Provigil ), armodafinil ( Nuvigil ), methylphenidate ( Ritalin and other brand names) or dextroamphetamine ( Dexedrine ), as well as with regularly scheduled short naps during the day. Cataplexy and sleep paralysis can be treated with a variety of medicines that can make you more resistant to entering REM sleep. Most of these medicines were developed for use as antidepressants. Examples of potentially effective medications include protriptyline ( Vivactil ), venlafaxine ( Effexor ) and fluoxetine ( Prozac ). Cataplexy also can be treated with sodium oxybate (also called gamma hydroxybutyrate or Xyrem ), although the use of this drug is tightly controlled because it has been abused recreationally.

For reasons that are not well understood, a low dose of this medicine reduces cataplexy attacks and improves daytime sleepiness in people who have narcolepsy with cataplexy, even though the drug causes sedation in most people without narcolepsy. Psychological counseling may be important for difficulties associated with self-esteem and for emotional support, especially since people with narcolepsy have difficulty doing tasks that require concentration, and may be regarded as unmotivated by family and peers. When To Call a Professional Call a doctor if you are excessively sleepy during the day. You should be evaluated as quickly as possible if episodes occur while you are driving a car or operating machinery. Prognosis People with narcolepsy have a significantly higher risk of death or serious injury resulting from motor vehicle or job-related accidents, and they must take care to avoid situations where such accidents might occur.

Learn more about Narcolepsy Narcolepsy And You: This Is What It's Really Like To Have Narcolepsy Narcolepsy And You: This Is What It's Really Like To Have Narcolepsy Feb 26, 2014 05:26 PM By Susan Scutti Close E-mail A nondescript man lost in his forties, Dee Daud has a visible bruise on his right cheek and a scar on his forearm. His greying hair is closely cropped, accentuating not only a British smile, but also a nose that has been broken more than once. His voice is monotone, the hollow tone of someone hoping to avoid emotion. Each time he laughs, his neck goes slack and he nods off almost immediately afterward. How does Daud account for all these bewildering characteristics? Simple. He has narcolepsy. Described as a sleep disorder, a medical disorder, a neurological disorder, and, most recently, an autoimmune disorder, all and none of those labels precisely convey what it means to have poor control over your sleep-wake cycles.

People with narcolepsy experience “ sleep attacks ,” or sudden, irresistible temptations to sleep that can strike at any time and may last a few seconds or several minutes. At the same time, they often cannot sleep at night, while feeling extremely sleepy throughout the day. Symptoms also include sleep paralysis, hallucinations, and cataplexy, which affect about 70 percent of all people with narcolepsy. Cataplexy is unique to narcolepsy — no other disease causes this sudden weakness of the muscles, especially in the legs but also in the face and neck, that is usually brought on by strong emotion, laughter in particular. Firsthand Accounts Most people begin to develop symptoms of this incurable disorder somewhere between the ages of 10 and 20, though it can appear later in life, though most commonly it will become evident before the age of 40. The condition occurs more frequently in men than in women. Sadly, the average time between the date symptoms first appear and a medical diagnosis is 10 years and in that time, people who suffer narcolepsy are often seen by others as unusual, lazy, or simply crazy.

Since many people experience their first symptoms while still in their teens, they are particularly vulnerable to feeling isolated, depressed, and hopeless. People with narcolepsy experience “sleep attacks,” or sudden, irresistible temptations to sleep that can strike at any time and may last a few seconds or several minutes: But what's it like to suffer from this neurological disorder? Photo courtesy of Shutterstock . “Up until then, I had been an honors student and on the JV softball team, as well as taking part in tons of other after school activities,” Amanda Vasas wrote in a first person account of her disorder. Once her symptoms began, all that changed. “My life was in shambles. My mother was a complete wreck and wouldn’t let me out of her sight, or even out of the house, out of fear that I would inevitably come crashing down to my doom [...] Since I could never go out, my friends stopped talking to me.” The picture Vasas paints is vivid and bleak. Because people with severe cases of narcolepsy may fall asleep anywhere, anytime, they live a life of great danger. This lifelong disorder, then, is managed with difficulty while the risks of becoming unemployable or a social outcast mount.

Joyce Scannell , who was haunted by hallucinations in early childhood, always knew something was wrong but wasn’t diagnosed until she was a divorced mother of three and well into her adult years. Although the diagnosis helped explain her sleep attacks and other symptoms, she did not immediately find relief in medication — she says she “spent a decade trying different medicines and therapies” — and little could be done about her employment prospects. “I had wanted to be an elementary school librarian, but realized I needed a job with more flexibility so I could fit in my naps and work on my own sleep schedule,” another narcoleptic, Tesa Schmidt , wrote. “I cannot have a roommate because of my daily naps and strict sleep schedule," she wrote, adding "...the normal life looks like heaven from this side of the fence.” Such are the thoughts of those with this disability. Even when making light of their condition, asking each other, "Where are the weirdest places you've fallen asleep?" sufferers sound a despairing note with their answers, including as much tragedy as comedy: While walking across the kitchen with a plate of food. Needless to say the food was around me when I woke up. The shower.

I don't even think I can count the number of times I've fallen asleep in the shower and lately I've been stressed so it's almost every day. On the toilet at work (my friends wondered why I had been gone so long and came to find me). Once I was in a very long line at the grocery. I fell asleep leaning against my shopping cart. On top of the dishwasher (it was winter and I was cold, so I sat on the countertop above the dishwasher to keep warm and fell asleep) I've fallen asleep while walking up the stairs only to find myself at the bottom again. I had a full collapse while talking to my supervisor at work. That one was amusing as he just looked at me when I stood back up. I once fell asleep while kneeling at Mass. During “the act.” I crawled in to a parked car and was woken up by the owner who stole all my money before I really knew what was happening. I fell asleep when I was getting my tooth drilled for a crown the other day. (I had cracked my tooth trying to stay awake at work.) Underneath my Volkswagen Vanagon while working on it.

A few months ago, I fell asleep for possibly 10-15 minutes while I was getting a massive tattoo on my leg. When I was 10 I fell asleep in the Underground when I was in England. Probably the weirdest place for me to fall asleep has been a live concert with really loud music. One thing that is heartening about narcolepsy is those who suffer from this disorder have established a thriving online community , apparently international in scope, where one and all can share not only their personal experiences but also medical information. That said, Vasas told Medical Daily in an email, "I've noticed there's mostly only support for people over the age of 40. I'd love to start a group for people 30 and younger, because I think lots of people feel lost because when you're young others tend to confuse a disorder like narcolepsy for just laziness, and that stinks." She may just get her wish; narcolepsy affects about one in every 2,000 people in the U.S. — about 175,000 people — and roughly three million people worldwide.

The frequency of narcolepsy varies from country to country , with it being most common in Japan, and most rare in Israel, suggesting it may be linked to a genetic cause. A possible cause or link to the cause of narcolepsy is lack of a chemical called hypocretin, which is normally produced in the hypothalamus. Some researchers believe the body's immune system attacks the cells that produce hypocretin. Interestingly, narcoleptics generally experience the REM stage of sleep within five minutes, while most people do not experience REM sleep until an hour or so into the sleep cycle. This is possibly what gives rise to their vivid dreams, which often take the form of nightmares. To gain a greater understanding of narcolepsy, this video from National Geographic follows Dee Daud, allowing you to see for yourself what it really means to have narcolepsy. What is Narcolepsy? (NINDS) - American Sleep Association What is Narcolepsy? (NINDS) (NINDS, NIH, 3/3007) Narcolepsy is a chronic neurological disorder caused by the brain’s inability to regulate sleep -wake cycles normally. At various times throughout the day, people with narcolepsy experience fleeting urges to sleep.

If the urge becomes overwhelming, patients fall asleep for periods lasting from a few seconds to several minutes. In rare cases, some people may remain asleep for an hour or longer. Narcoleptic sleep episodes can occur at any time, and thus frequently prove profoundly disabling. People may involuntarily fall asleep while at work or at school, when having a conversation, playing a game, eating a meal, or, most dangerously, when driving an automobile or operating other types of potentially hazardous machinery. In addition to daytime sleepiness, three other major symptoms frequently characterize narcolepsy: cataplexy, or the sudden loss of voluntary muscle tone; vivid hallucinations during sleep onset or upon awakening; and brief episodes of total paralysis at the beginning or end of sleep. Contrary to common beliefs, people with narcolepsy do not spend a substantially greater proportion of their time asleep during a 24-hour period than do normal sleepers. In addition to daytime drowsiness and involuntary sleep episodes, most patients also experience frequent awakenings during nighttime sleep. For these reasons, narcolepsy is considered to be a disorder of the normal boundaries between the sleeping and waking states.

For most adults, a normal night’s sleep lasts about 8 hours and is composed of four to six separate sleep cycles. A sleep cycle is defined by a segment of non-rapid eye movement (NREM) sleep followed by a period of rapid eye movement (REM) sleep. The NREM segment can be further divided into stages according to the size and frequency of brain waves. REM sleep , in contrast, is accompanied by bursts of rapid eye movement (hence the acronym REM sleep) along with sharply heightened brain activity and temporary paralysis of the muscles that control posture and body movement. When subjects are awakened from sleep, they report that they were “having a dream” more often if they had been in REM sleep than if they had been in NREM sleep. Transitions from NREM to REM sleep are governed by interactions among groups of neurons (nerve cells) in certain parts of the brain. Scientists now believe that narcolepsy results from disease processes affecting brain mechanisms that regulate REM sleep. For normal sleepers a typical sleep cycle is about 100 – 110 minutes long, beginning with NREM sleep and transitioning to REM sleep after 80 – 100 minutes.

But, people with narcolepsy frequently enter REM sleep within a few minutes of falling asleep. Who Gets Narcolepsy? <topic_body> Narcolepsy is not rare, but it is an underrecognized and underdiagnosed condition. According to current estimates, the disorder affects about one in every 2,000 Americans-a total of more than 135,000 individuals. After obstructive sleep apnea and restless legs syndrome ,* narcolepsy is the third most frequently diagnosed primary sleep disorder found in patients seeking treatment at sleep clinics. But the exact prevalence rate remains uncertain, and the disorder may affect a larger segment of the population than currently estimated. Narcolepsy appears throughout the world in every racial and ethnic group, affecting males and females equally. But prevalence rates vary among populations. Compared to the U.S. population, for example, the prevalence rate is substantially lower in Israel (about one per 500,000) and considerably higher in Japan (about one per 600). Most cases of narcolepsy are sporadic-that is, the disorder occurs independently in individuals without strong evidence of being inherited. But familial clusters are known to occur.

Up to 10 percent of patients diagnosed with narcolepsy with cataplexy report having a close relative with the same symptoms. Genetic factors alone are not sufficient to cause narcolepsy. Other factors-such as infection, immune-system dysfunction, trauma, hormonal changes, stress-may also be present before the disease develops. Thus, while close relatives of people with narcolepsy have a statistically higher risk of developing the disorder than do members of the general population, that risk remains low in comparison to diseases that are purely genetic in origin. * Obstructive sleep apnea is a temporary cessation of breathing that occurs repeatedly during sleep and is caused by a narrowing of the airway. Restless legs syndrome is a neurological disorder characterized by unpleasant sensations-burning, creeping, tugging-in the legs and an uncontrollable urge to move when at rest What are the Symptoms? <topic_body> People with narcolepsy experience highly individualized patterns of REM sleep disturbances that tend to begin subtly and may change dramatically over time. The most common major symptom, other than excessive daytime sleepiness (EDS), is cataplexy, which occurs in about 70 percent of all patients. Sleep paralysis and hallucinations are somewhat less common.

Only 10 to 25 percent of patients, however, display all four of these major symptoms during the course of their illness. Excessive daytime sleepiness EDS, the symptom most consistently experienced by almost all patients, is usually the first to become clinically apparent. Generally, EDS interferes with normal activities on a daily basis, whether or not patients have sufficient sleep at night. People with EDS describe it as a persistent sense of mental cloudiness, a lack of energy, a depressed mood, or extreme exhaustion. Many find that they have great difficulty maintaining their concentration while at school or work. Some experience memory lapses. Many find it nearly impossible to stay alert in passive situations, as when listening to lectures or watching television. People tend to awaken from such unavoidable sleeps feeling refreshed and finding that their feelings of drowsiness and fatigue subside for an hour or two. Involuntary sleep episodes are sometimes very brief, lasting no more than seconds at a time. As many as 40 percent of all people with narcolepsy are prone to automatic behavior during such “microsleeps.” They fall asleep for a few seconds while performing a task but continue carrying it through to completion without any apparent interruption.

During these episodes, people are usually engaged in habitual, essentially “second nature” activities such as taking notes in class, typing, or driving. They cannot recall their actions, and their performance is almost always impaired during a microsleep. 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, patients may get lost or have an accident. Cataplexy Cataplexy is a sudden loss of muscle tone that leads to feelings of weakness and a loss of voluntary muscle control. Attacks can occur at any time during the waking period, with patients usually experiencing their first episodes several weeks or months after the onset of EDS. But in about 10 percent of all cases, cataplexy is the first symptom to appear and can be misdiagnosed as a manifestation of a seizure disorder. Cataplectic attacks vary in duration and severity. The loss of muscle tone can be barely perceptible, involving no more than a momentary sense of slight weakness in a limited number of muscles, such as mild drooping of the eyelids.

The most severe attacks result in a complete loss of tone in all voluntary muscles, leading to total physical collapse in which patients 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 seizure disorders. Although cataplexy can occur spontaneously, it is more often triggered by sudden, strong emotions such as fear, anger, stress, excitement, or humor. Laughter is reportedly the most frequent trigger. The loss of muscle tone during a cataplectic episode resembles the interruption of muscle activity that naturally occurs during REM sleep. A group of neurons in the brainstem ceases activity during REM sleep, inhibiting muscle movement. Using an animal model, scientists have recently learned that this same group of neurons becomes inactive during cataplectic attacks, a discovery that provides a clue to at least one of the neurological abnormalities contributing to human narcoleptic symptoms. Sleep paralysis The temporary inability to move or speak while falling asleep or waking up also parallels REM-induced inhibitions of voluntary muscle activity. This natural inhibition usually goes unnoticed by people who experience normal sleep because it occurs only when they are fully asleep and entering the REM stage at the appropriate time in the sleep cycle.

Experiencing sleep paralysis resembles undergoing a cataplectic attack affecting the entire body. As with cataplexy, people remain fully conscious. Cataplexy and sleep paralysis are frightening events, especially when first experienced. Shocked by suddenly being unable to move, many patients fear that they may be permanently paralyzed or even dying. However, 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 Hallucinations can accompany sleep paralysis or can occur in isolation when people are falling asleep or waking up. Referred to as hypnagogic hallucinations when accompanying sleep onset and ashypnopompic hallucinations when occurring during awakening, these delusional experiences are unusually vivid and frequently frightening. Most often, the content is primarily visual, but any of the other senses can be involved. These hallucinations represent another intrusion of an element of REM sleep-dreaming-into the wakeful state. When Do Symptoms Appear? <topic_body> In most cases, symptoms first appear when people are between the ages of 10 and 25 but narcolepsy can become clinically apparent at virtually any age.

Many patients first experience symptoms between the ages of 35 and 45. A smaller number initially manifest the disorder around the ages of 50 to 55. Narcolepsy can also develop early in life, probably more frequently than is generally recognized. For example, 3-year-old children have been diagnosed with the disorder. Whatever the age of onset, patients find that the symptoms tend to get worse over the two to three decades after the first symptoms appear. Many older patients find that some daytime symptoms decrease in severity after age 60. Narcoleptic symptoms, especially EDS, often prove more severe when the disorder develops early in life rather than during the adult years. Experts have also begun to recognize that narcolepsy sometimes contributes to certain childhood behavioral problems, such as attention-deficit hyperactivity disorder, and must be addressed before the behavioral problem can be resolved. If left undiagnosed and untreated, narcolepsy can pose special problems for children and adolescents, interfering with their psychological, social, and cognitive development and undermining their ability to succeed at school. For some young people, feelings of low self-esteem due to poor academic performance may persist into adulthood. What Causes Narcolepsy?

<topic_body> The cause of narcolepsy remains unknown but during the past decade, scientists have made considerable progress in understanding its pathogenesis and in identifying genes strongly associated with the disorder. Researchers have also discovered abnormalities in various parts of the brain involved in regulating REM sleep that appear to contribute to symptom development. Experts now believe it is likely that-similar to many other complex, chronic neurological diseases-narcolepsy involves multiple factors interacting to cause neurological dysfunction and REM sleep disturbances. A number of variant forms (alleles) of genes located in a region of chromosome 6 known as the HLA complex have proved to be strongly, although not invariably, associated with narcolepsy. The HLA complex comprises a large number of interrelated genes that regulate key aspects of immune-system function. The majority of people diagnosed with narcolepsy are known to have specific variants in certain HLA genes. However, these variations are neither necessary nor sufficient to cause the disorder. Some people with narcolepsy do not have the variant genes, while many people in the general population without narcolepsy do possess these variant genes.

Thus it appears that specific variations in HLA genes increase an individual’s predisposition to develop the disorder-possibly through a yet-undiscovered route involving changes in immune-system function-when other causative factors are present. Many other genes besides those making up the HLA complex may contribute to the development of narcolepsy. Groups of neurons in several parts of the brainstem and the central brain, including the thalamus and hypothalamus, interact to control sleep. Large numbers of genes on different chromosomes control these neurons’ activities, any of which could contribute to development of the disease. Scientists studying narcolepsy in dogs have identified a mutation in a gene on chromosome 12 that appears to contribute to the disorder. This mutated gene disrupts the processing of a special class of neurotransmitters called hypocretins (also known as orexins) that are produced by neurons located in the hypothalamus. Neurotransmitters are special proteins that neurons produce to communicate with each other and to regulate biological processes. The neurons that produce hypocretins are active during wakefulness, and research suggests that they keep the brain systems needed for wakefulness from shutting down unexpectedly. Mice born without functioning hypocretin genes develop many symptoms of narcolepsy.

Except in rare cases, narcolepsy in humans is not associated with mutations of the hypocretin gene. However, scientists have found that brains from humans with narcolepsy often contain greatly reduced numbers of hypocretin-producing neurons. Certain HLA subtypes may increase susceptibility to an immune attack on hypocretin neurons in the hypothalamus, leading to degeneration of neurons in the hypocretin system. Other factors also may interfere with proper functioning of this system. The hypocretins regulate appetite and feeding behavior in addition to controlling sleep. Therefore, the loss of hypocretin-producing neurons may explain not only how narcolepsy develops in some people, but also why people with narcolepsy have higher rates of obesity compared to the general population. Other factors appear to play important roles in the development of narcolepsy. Some rare cases are known to result from traumatic injuries to parts of the brain involved in REM sleep or from tumor growth and other disease processes in the same regions.

Infections, exposure to toxins, dietary factors, stress, hormonal changes such as those occurring during puberty or menopause, and alterations in a person’s sleep schedule are just a few of the many factors that may exert direct or indirect effects on the brain, thereby possibly contributing to disease development. How is Narcolepsy Diagnosed? <topic_body> Narcolepsy is not definitively diagnosed in most patients until 10 to 15 years after the first symptoms appear. This unusually long lag-time is due to several factors, including the disorder’s subtle onset and the variability of symptoms. As important, however, is the fact that the public is largely unfamiliar with the disorder, as are many health professionals . When symptoms initially develop, people often do not recognize that they are experiencing the onset of a distinct neurological disorder and thus fail to seek medical treatment. A clinical examination and exhaustive medical history are essential for diagnosis and treatment. However, none of the major symptoms is exclusive to narcolepsy.

EDS-the most common of all narcoleptic symptoms-can result from a wide range of medical conditions, including other sleep disorders such as sleep apnea, various viral or bacterial infections, mood disorders such as depression, and painful chronic illnesses such as congestive heart failure and rheumatoid arthritis that disrupt normal sleep patterns. Various medications can also lead to EDS, as can consumption of caffeine, alcohol, and nicotine. Finally, sleep deprivation has become one of the most common causes of EDS among Americans. This lack of specificity greatly increases the difficulty of arriving at an accurate diagnosis based on a consideration of symptoms alone. Thus, a battery of specialized tests, which can be performed in a sleep disorders clinic, is usually required before a diagnosis can be established. Two tests in particular are considered essential in confirming a diagnosis of narcolepsy: the polysomnogram (PSG) and the multiple sleep latency test (MSLT). The PSG is an overnight test that takes continuous multiple measurements while a patient is asleep to document abnormalities in the sleep cycle. It records heart and respiratory rates, electrical activity in the brain through electroencephalography (EEG), and nerve activity in muscles through electromyography (EMG).

A PSG can help reveal whether REM sleep occurs at abnormal times in the sleep cycle and can eliminate the possibility that an individual’s symptoms result from another condition. The MSLT is performed during the day to measure a person’s tendency to fall asleep and to determine whether isolated elements of REM sleep intrude at inappropriate times during the waking hours. As part of the test, an individual is asked to take four or five short naps usually scheduled 2 hours apart over the course of a day. As the name suggests, the sleep latency test measures the amount of time it takes for a person to fall asleep. Because sleep latency periods are normally 10 minutes or longer, a latency period of 5 minutes or less is considered suggestive of narcolepsy. The MSLT also measures heart and respiratory rates, records nerve activity in muscles, and pinpoints the occurrence of abnormally timed REM episodes through EEG recordings. If a person enters REM sleep either at the beginning or within a few minutes of sleep onset during at least two of the scheduled naps, this is also considered a positive indication of narcolepsy. What Treatments are Available? <topic_body> Narcolepsy cannot yet be cured.

But EDS and cataplexy, the most disabling symptoms of the disorder, can be controlled in most patients with drug treatment. Often the treatment regimen is modified as symptoms change. For decades, doctors have used central nervous system stimulants-amphetamines such as methylphenidate, dextroamphetamine, methamphetamine, and pemoline-to alleviate EDS and reduce the incidence of sleep attacks. For most patients these medications are generally quite effective at reducing daytime drowsiness and improving levels of alertness. However, they are associated with a wide array of undesirable side effects so their use must be carefully monitored. Common side effects include irritability and nervousness, shakiness, disturbances in heart rhythm, stomach upset, nighttime sleep disruption, and anorexia. Patients may also develop tolerance with long-term use, leading to the need for increased dosages to maintain effectiveness. In addition, doctors should be careful when prescribing these drugs and patients should be careful using them because the potential for abuse is high with any amphetamine. In 1999, the FDA approved a new non-amphetamine wake-promoting drug called modafinil for the treatment of EDS.

In clinical trials , modafinil proved to be effective in alleviating EDS while producing fewer, less serious side effects that do ampehtmines. Headache is the most commonly reported adverse effect. Long-term use of modafinil does not appear to lead to tolerance. Two classes of antidepressant drugs have proved effective in controlling cataplexy in many patients: tricyclics (including imipramine, desipramine, clomipramine, and protriptyline) and selective serotonin reuptake inhibitors (including fluoxetine and sertraline). In general, antidepressants produce fewer adverse effects than do amphetamines. But troublesome side effects still occur in some patients, including impotence, high blood pressure, and heart rhythm irregularities. On July 17, 2002, the FDA approved Xyrem (sodium oxybate or gamma hydroxybutyrate, also known as GHB) for treating people with narcolepsy who experience episodes of cataplexy. Due to safety concerns associated with the use of this drug, the distribution of Xyrem is tightly restricted. Related posts:

Question: If someone is narcoleptic, what do they tend to do?
Answer: Fall asleep