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Narcolepsy
Narcolepsy
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Narcolepsy is a chronic sleep disorder, or dyssomnia, characterized by..............Zzzzzzzzzzzzzzzzzzzzzzzzzzzz.

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 {{Infobox Disease |Name=Narcolepsy |DiseasesDB=8801 |ICD10={{ICD10|G|47|4|g|40}} |ICD9={{ICD9|347}} |OMIM=161400 |eMedicineSubj=neuro |eMedicineTopic=522 |MeshID=D009290}}
+'''Narcolepsy''' is  a [[chronic (medicine)|chronic]] [[sleep disorder]], or [[dyssomnia]], characterized by..............Zzzzzzzzzzzzzzzzzzzzzzzzzzzz.
-'''Narcolepsy''' is  a [[chronic (medicine)|chronic]] [[sleep disorder]], or [[dyssomnia]], characterized by [[excessive daytime sleepiness]] (EDS) in which a person experiences extreme [[fatigue (medical)|fatigue]] and possibly falls asleep at inappropriate times, such as while at work or at school. Narcoleptics usually experience disturbed nocturnal sleep and an abnormal daytime sleep pattern, which is often confused with [[insomnia]]. When a narcoleptic falls asleep they generally experience the [[REM sleep|REM]] stage of sleep within 10 minutes; whereas most people do not experience REM sleep until after 90 minutes. There is no evidence to suggest that narcoleptics tend to have a shorter life span.
-Another problem that some narcoleptics experience is [[cataplexy]], a sudden muscular weakness brought on by strong emotions (though many people experience cataplexy without having an emotional trigger).<ref>http://adam.about.com/reports/Narcolepsy.htm</ref> It often manifests as muscular weaknesses ranging from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees, or a total collapse. Usually only speech is slurred, vision is impaired (double vision, inability to focus), but hearing and awareness remain normal. In some rare cases, an individual's body becomes [[paralyzed]] and muscles become stiff.
-Narcolepsy is a neurological sleep disorder. It is not caused by mental illness or psychological problems. It is most likely affected by a number of genetic abnormalities that affect specific biologic factors in the brain, combined with a set off from environment, such as a virus.<ref>Entry [http://www.umm.edu/patiented/articles/what_causes_narcolepsy_000098_2.htm'''Narcolepsy-Causes'''] in the '''University of Maryland Medical Center''' Harvey Simon, Associate Prof of Medicine, Harvard University & David Zieve, Medical Director of A.D.A.M, Inc.</ref>
-The term ''narcolepsy'' derives from the French word ''narcolepsie'' created by the French physician [[Jean-Baptiste-Édouard Gélineau]] by combining the [[Greek Language|Greek]] νάρκη (''narkē'', "numbness" or "stupor"),<ref>[http://en.wiktionary.org/wiki/%CE%BD%CE%AC%CF%81%CE%BA%CE%B7 http://en.wiktionary.org/wiki/νάρκη]</ref><ref>Entry [http://dictionary.reference.com/browse/Narcolepsy '''Narcolepsy.'''] in the '''Online Etymology Dictionary.''' Douglas Harper, Historian. 18 Sep 2007.</ref> and λῆψις (''lepsis''), "attack" or "seizure".<ref>http://en.wiktionary.org/wiki/-lepsy</ref>
-==Signs and symptoms==
-The main characteristic of narcolepsy is [[excessive daytime sleepiness]] (EDS), even after adequate nighttime sleep. A person with narcolepsy is likely to become drowsy or fall asleep or just be very tired throughout the day, often at inappropriate times and places. Daytime naps may occur with little warning and may be physically irresistible. These naps can occur several times a day. They are typically refreshing, but only for a few hours. Drowsiness may persist for prolonged periods of time. In addition, nighttime sleep may be fragmented with frequent awakenings.
-The classic symptoms of the disorder, often referred to as the "tetrad of narcolepsy," are [[cataplexy]], [[sleep paralysis]], [[hypnagogic hallucination]]s, and excessive daytime sleepiness.<ref name="Kandel">{{cite book |last=Kandel |first=Eric R. |coauthors=James H. Schwartz, Thomas M. Jessell |title=Principles of Neural Science |publisher= McGraw-Hill |edition=4th |page=949 |isbn=0-8385-7701-6}}</ref> Other symptoms include [[automatic behavior]]s.<ref>[http://www.medicinenet.com/narcolepsy/article.htm Narcolepsy MedicineNet.com]</ref><ref>[http://www.ncbi.nlm.nih.gov/pubmed/422531 Narcolepsy and automatic behavior: a case report. J Clin Psychiatry. 1979 - PubMed result]</ref> These symptoms may not occur in all patients. Cataplexy is an episodic condition featuring loss of muscle function, ranging from slight weakness (such as limpness at the neck or knees, sagging facial muscles, or inability to speak clearly) to complete body collapse. Episodes may be triggered by sudden emotional reactions such as [[laughter]], [[anger]], surprise, or [[fear]], and may last from a few seconds to several minutes. The person remains conscious throughout the episode. In some cases, cataplexy may resemble epileptic seizures.<ref>http://www.taumed.com/content/adam/browse.jsp?pid=10&cid=000098</ref> Sleep paralysis is the temporary inability to talk or move when waking (or less often, when falling asleep). It may last a few seconds to minutes. This is often frightening but is not dangerous. Hypnagogic hallucinations are vivid, often frightening, dreamlike experiences that occur while dozing, falling asleep and/or while awakening.
-Automatic behavior means that a person continues to function (talking, putting things away, etc.) during sleep episodes, but awakens with no memory of performing such activities. It is estimated that up to 40 percent of people with narcolepsy experience automatic behavior during sleep episodes. Sleep paralysis and hypnagogic hallucinations also occur in people who do not have narcolepsy, but more frequently in people who are suffering from extreme lack of sleep. Cataplexy is generally considered to be unique to narcolepsy and is analogous to sleep paralysis in that the usually protective paralysis mechanism occurring during sleep is inappropriately activated. The opposite of this situation (failure to activate this protective paralysis) occurs in [[rapid eye movement behavior disorder]].
-In most cases, the first symptom of narcolepsy to appear is excessive and overwhelming daytime sleepiness. The other symptoms may begin alone or in combination months or years after the onset of the daytime naps. There are wide variations in the development, severity, and order of appearance of cataplexy, sleep paralysis, and hypnagogic hallucinations in individuals. Only about 20 to 25 percent of people with narcolepsy experience all four symptoms. The excessive daytime sleepiness generally persists throughout life, but sleep paralysis and hypnagogic hallucinations may not.
-Although these are the common symptoms of narcolepsy, many people with narcolepsy also suffer from [[insomnia]] for extended periods of time. The symptoms of narcolepsy, especially the excessive daytime sleepiness and cataplexy, often become severe enough to cause serious problems in a person's social, personal, and professional life. Normally, when an individual is awake, [[brain wave]]s show a regular rhythm. When a person first falls asleep, the brain waves become slower and less regular. This sleep state is called non-rapid eye movement ([[NREM]]) sleep. After about an hour and a half of NREM sleep, the brain waves begin to show a more active pattern again. This sleep state, called [[REM sleep]] (rapid eye movement sleep), is when most remembered [[dream]]ing occurs. Associated with the EEG-observed waves during REM sleep, muscle atonia is present (called [[REM atonia]]).
-In narcolepsy, the order and length of NREM and REM sleep periods are disturbed, with REM sleep occurring at sleep onset instead of after a period of NREM sleep. Thus, narcolepsy is a disorder in which REM sleep appears at an abnormal time. Also, some of the aspects of REM sleep that normally occur only during sleep—lack of muscular control, sleep paralysis, and vivid dreams—occur at other times in people with narcolepsy. For example, the lack of muscular control can occur during wakefulness in a cataplexy episode; it is said that there is intrusion of REM atonia during wakefulness. Sleep paralysis and vivid dreams can occur while falling asleep or waking up. Simply put, the brain does not pass through the normal stages of dozing and deep sleep but goes directly into (and out of) rapid eye movement (REM) sleep.
-This has several consequences. Night time sleep does not include as much deep sleep, so the brain tries to "catch up" during the day, hence EDS. People with narcolepsy may visibly fall asleep at unpredicted moments (such motions as head bobbing are common). People with narcolepsy fall quickly into what appears to be very deep sleep, and they wake up suddenly and can be disoriented when they do (dizziness is a common occurrence). They have very vivid dreams, which they often remember in great detail. People with narcolepsy may dream even when they only fall asleep for a few seconds.
-==Causes==
-[[File:1R02 crystallography.png|thumb|A depiction of the neuropeptide '''Orexin A'''. People with narcolepsy often have a reduced number of neurons that produce this protein.]]
-Although the cause of narcolepsy was not determined for many years after its discovery, scientists had discovered conditions that seemed to be associated with an increase in an individual's risk of having the disorder. Specifically, there appeared to be a strong link between narcoleptic individuals and certain genetic conditions. One factor that seemed to predispose an individual to narcolepsy involved an area of Chromosome 6 known as the [[human leukocyte antigen|HLA]] complex.<ref name="pmid10984567">{{cite journal |author=Klein J, Sato A |title=The HLA system. Second of two parts |journal=N. Engl. J. Med. |volume=343 |issue=11 |pages=782–6 |year=2000 |month=September |pmid=10984567 |doi= 10.1056/NEJM200009143431106}}</ref> There appeared to be a correlation between narcoleptic individuals and certain variations in HLA genes, although it was not required for the condition to occur. Certain variations in the HLA complex were thought to increase the risk of an [[auto-immune]] response to [[protein]]-producing neurons in the brain. The protein produced, called [[hypocretin]] or [[orexin]], is responsible for controlling appetite and sleep patterns.<ref name="mignot">{{cite journal |last=Mignot |first=E |year=2001 |title=A commentary on the neurobiology of the hypocretin/orexin system |journal=Neuropsychopharmacology |volume=25 |page=S5-13 |pmid=11682267 |issue=5 Suppl |doi= 10.1016/S0893-133X(01)00316-5}}</ref> Individuals with narcolepsy often have reduced numbers of these protein-producing neurons in their brains.<ref name=mignot/> In 2009 the autoimmune hypothesis was supported by research carried out at Stanford University School of Medicine.<ref name="pmid19412176">{{cite journal |author=Hallmayer J, Faraco J, Lin L, et al. |title=Narcolepsy is strongly associated with the T-cell receptor alpha locus |journal=Nat. Genet. |volume=41 |issue=6 |pages=708–11 |year=2009 |month=June |pmid=19412176 |doi= 10.1038/ng.372 |pmc=2803042}}</ref><ref name="url_eurekalert">{{cite web |url=http://www.eurekalert.org/pub_releases/2009-05/sumc-nia042809.php |title=Narcolepsy is an autoimmune disorder, Stanford researcher says |date=2009-05-03 |work=EurekAlert |publisher=American Association for the Advancement of Science |accessdate=2009-05-31}}</ref>
-The neural control of normal sleep states and the relationship to narcolepsy are only partially understood. In humans, narcoleptic sleep is characterized by a tendency to go abruptly from a waking state to REM sleep with little or no intervening non-REM sleep. The changes in the motor and [[proprioceptive]] systems during REM sleep have been studied in both human and animal models. During normal REM sleep, spinal and brainstem [[alpha motor neuron]] [[depolarization]] produces almost complete [[atonia]] of [[skeletal muscle]]s via an inhibitory descending reticulospinal pathway. [[Acetylcholine]] may be one of the [[neurotransmitter]]s involved in this pathway. In narcolepsy, the reflex inhibition of the motor system seen in cataplexy is believed to be identical to that seen in normal REM sleep.{{Citation needed|date=February 2007}}
-In 2004 researchers in Australia induced narcolepsy-like symptoms in mice by injecting them with antibodies from narcoleptic humans. The research has been published in the Lancet providing strong evidence suggesting that some cases of narcolepsy might be caused by autoimmune disease.<ref>{{cite web |url=http://news.bbc.co.uk/1/hi/health/4081225.stm |title=BBC News article |date=2004-12-13 |accessdate=2010-01-06}}</ref> Narcolepsy is strongly associated with [[HLA-DQB1]]*0602 [[genotype]].<ref name="Maret">{{cite journal |last=Maret |first =S |coauthors=Tafti M |title=Genetics of narcolepsy and other major sleep disorders |journal=Swiss Medical Weekly |volume=135 |issue=45-46 |pages=662–5 |publisher=EMH Swiss Medical Publishers Ltd. |month=November |year=2005 |url=http://www.smw.ch/docs/pdf200x/2005/45/smw-11162.pdf |format=PDF |pmid=16453205 |accessdate=2008-03-07}}</ref> There is also an association with [[HLA-DR2]] and [[HLA-DQ1]]. This may represent [[linkage disequilibrium]]. Despite the experimental evidence in human narcolepsy that there may be an inherited basis for at least some forms of narcolepsy, the mode of inheritance remains unknown. Some cases are associated with genetic diseases such as [[Niemann-Pick disease]]<ref>{{cite journal |author=Vankova J, Stepanova I, Jech R, et al. |title=Sleep disturbances and hypocretin deficiency in Niemann-Pick disease type C |journal=Sleep |volume=26 |issue=4 |pages= 427–30 |year=2003 |month=June |pmid=12841368}}</ref> or [[Prader-Willi syndrome]].<ref>{{cite journal |author=Manni R, Politini L, Nobili L, et al. |title=Hypersomnia in the Prader Willi syndrome: clinical-electrophysiological features and underlying factors |journal=Clin Neurophysiol |volume=112 |issue=5 |pages=800–5 |year=2001 |month=May |pmid=11336895 |url= http://linkinghub.elsevier.com/retrieve/pii/S1388-2457(01)00483-7 |doi=10.1016/S1388-2457(01)00483-7}}</ref>
-Currently a link between [[GlaxoSmithKline]]'s swine flu vaccine [[Pandemrix]] and childhood narcolepsy is being investigated due to increased prevalence of narcolepsy in Finnish and Swedish children after [[vaccinations]]. Finland's National Institute of Health and Welfare is recommending that Pandemrix vaccinations are suspended pending further investigation into 15 reported cases of recently vaccinated children developing narcolepsy.<ref>{{cite news| url=http://www.lakemedelsverket.se/english/All-news/NYHETER-2010/The-MPA-investigates-reports-of-narcolepsy-in-patients-vaccinated-with-Pandemrix/| work=The Swedish Medical Products Agency | title=The MPA investigates reports of narcolepsy in patients vaccinated with Pandemrix | date=2010-08-18 | accessdate=2010-08-19}}</ref><ref>{{cite news| url=http://www.thl.fi/fi_FI/web/fi/tiedote?id=22930| work=National Institute of Health and Welfare | title=Terveyden ja hyvinvoinnin laitos suosittaa Pandemrix-rokotusten keskeyttämistä | date=2010-08-24 | accessdate=2010-08-24}}</ref>
-In Finland in mid-November 2010, 37 cases of children's narcolepsy had been reported as suspected adverse events of Pandemrix. This can compared to normal average of 3 cases of children's narcolepsy per year. <ref>[http://www.yle.fi/uutiset/news/2010/11/ties_between_big_pharma_and_thl_draw_complaints_2147563.html YLE News 17 November 2010: Ties Between Big Pharma and THL Draw Complaints]</ref>
-==Diagnosis==
-Diagnosis is relatively easy when all the symptoms of narcolepsy are present, but if the sleep attacks are isolated and cataplexy is mild or absent, diagnosis is more difficult. It is also possible for cataplexy to occur in isolation. Two tests that are commonly used in diagnosing narcolepsy are the [[polysomnogram]] and the [[multiple sleep latency test]] (MSLT). These tests are usually performed by a [[sleep medicine|sleep specialist]]. The polysomnogram involves continuous recording of sleep brain waves and a number of nerve and muscle functions during nighttime sleep. When tested, people with narcolepsy fall asleep rapidly, enter REM sleep early, and may awaken often during the night. The polysomnogram also helps to detect other possible sleep disorders that could cause daytime sleepiness.
-For the multiple sleep latency test, a person is given a chance to sleep every 2 hours during normal wake times. Observations are made of the time taken to reach various stages of sleep ([[sleep onset latency]]). This test measures the degree of daytime sleepiness and also detects how soon REM sleep begins. Again, people with narcolepsy fall asleep rapidly and enter REM sleep early.
-==Treatment==
-Treatment is tailored to the individual, based on symptoms and therapeutic response. The time required to achieve optimal control of symptoms is highly variable, and may take several months or longer. Medication adjustments are also frequently necessary, and complete control of symptoms is seldom possible. While oral medications are the mainstay of formal narcolepsy treatment, lifestyle changes are also important.
-The main treatment of excessive daytime sleepiness in narcolepsy is with [[central nervous system]] [[stimulant drug]]s such as [[methylphenidate]], [[racemic]] - [[amphetamine]], [[dextroamphetamine]], and [[methamphetamine]], or [[modafinil]] ([[Provigil]]), a new stimulant with a different pharmacologic mechanism, and more recently, [[armodafinil]] ([[Nuvigil]]). In Fall 2007 an alert for [[Modafinil#Severe adverse reactions|severe adverse skin reactions]] to modafinil was issued by the [[US Food and Drug Administration|FDA]].<ref>[http://www.fda.gov/cder/dsn/2007_fall/postmarketing.htm#modafinil Modafinil (marketed as Provigil): Serious Skin Reactions; FDA Drug Safety Newsletter]</ref> Other medications used are [[codeine]]<ref>{{cite journal |last1=Fry |first1=JM |last2=Pressman |first2=MR |last3=Diphillipo |first3=MA |last4=Forst-Paulus |first4=M |year= 1986 |title=Treatment of narcolepsy with codeine |journal=Sleep |volume=9 |pages=269–74 |pmid=3518019 |issue=1 Pt 2}}</ref> and [[selegiline]].<ref>{{cite journal |doi=10.1097/00002826-199508000-00002 |last1=Mayer |first1=G |last2=Ewert Meier |first2=K |last3=Hephata |first3=K |year=1995 |title=Selegeline hydrochloride treatment in narcolepsy. A double-blind, placebo-controlled study |journal= Clin Neuropharmacol |volume=18 |issue=4 |pages=306–19 |pmid=8665543}}</ref> Another drug that is used is [[atomoxetine]]<ref>{{cite web |url=http://med.stanford.edu/school/Psychiatry/narcolepsy/medications.html |title=Stanford Center for Narcolepsy article}}</ref> (Strattera), a non-stimulant and [[norepinephrine reuptake inhibitor]] (NRI), that has little or no abuse potential.<ref>{{cite web |url=http://adhdproject.curtin.edu.au/forms/STRATTERA%20PI%20(marketed%20products).pdf |format=PDF |title=Curtin University of Technology Article}}</ref> In many cases, planned regular short naps can reduce the need for pharmacological treatment of the EDS to a low or non-existent level.
-Cataplexy and other REM-sleep symptoms are frequently treated with [[tricyclic antidepressant]]s such as [[clomipramine]], [[imipramine]], or [[protriptyline]], as well as other drugs that suppress REM sleep. Venlafaxine (branded as Effexor XR by Wyeth Pharmaceuticals), an antidepressant which blocks the reuptake of serotonin and norepinephrine, has shown usefulness in managing symptoms of cataplexy,<ref>{{cite journal |last1=Caputo |first1=F |last2=Zoli |first2=G |last3=Provini |first3=Federica |last4= Albani |first4=Fiorenzo |last5=Riva |first5=Roberto |year=2007 |month=March |title=Treatment of narcolepsy with cataplexy |journal=Lancet |volume=369 |issue=9567 |pages=1080–1081 |doi= 10.1016/S0140-6736(07)60523-6 |pmid=17398302}}</ref> however, it has notable side-effects including sleep disruption.
-Another treatment option for narcolepsy is [[Xyrem]] (sodium oxybate) oral solution.  [[Xyrem]] is a [[prescription medication]] manufactured by Jazz Pharmaceuticals, and is approved by the [[U.S. Food and Drug Administration]] (FDA) for the treatment of [[cataplexy]] associated with narcolepsy <ref>{{cite web|url= http://www.accessdata.fda.gov/drugsatfda_docs/appletter/2002/21196ltr.pdf |title= FDA Approval Letter for Xyrem; Indication: Cataplexy associated with narcolepsy; 17 Jul 2002}}</ref> and [[Excessive daytime sleepiness|Excessive Daytime Sleepiness]] (EDS) associated with narcolepsy.<ref>{{cite web|url= http://www.accessdata.fda.gov/drugsatfda_docs/appletter/2005/021196s005ltr.pdf |title= FDA Approval Letter for Xyrem; Indication: EDS (Excessive Daytime Sleepiness) associated with narcolepsy; 18 Nov 2005}}</ref>  The [[American Academy of Sleep Medicine]] (AASM) recently recognized Xyrem as a standard of care for the treatment of cataplexy, daytime sleepiness, and disrupted sleep due to narcolepsy in its Practice Parameters for the Treatment of Narcolepsy and other Hypersomnias of Central Origin.  These recommendations are based upon careful review of the medical literature, and the designation “standard” of care “reflects a high degree of clinical certainty” based on strong empirical evidence.<ref>{{cite web|url= http://www.aasmnet.org/Resources/PracticeParameters/PP_narcolepsy.pdf |title= Practice Parameters for the Treatment of Narcolepsy and other Hypersomnias of Central Origin (Morgenthaler et al. Sleep. 2007;30:1705)}}</ref>
-[[Xyrem]] is the only medication specifically indicated and approved for cataplexy associated with narcolepsy. [[Xyrem]] has been shown to reduce symptoms of EDS associated with narcolepsy. While the exact mechanism of action is unknown, [[Xyrem]] is thought to improve the quality of nocturnal sleep by increasing the prevalence of slow wave (delta) sleep (as this is the time when the brain is least active and therefore most at rest and able to rebuild and repair itself physiologically). [[Xyrem]] appears to help sufferers much more effectively than the hypnotic class of medications typically used for insomnia (hypnotics tend to obstruct delta wave sleep), so it can be vital to be properly diagnosed as narcoleptic rather than insomniac.
-Using stimulants to mask daytime sleepiness does not address the actual cause of the problem. Stimulants may provide some assistance with daytime activity, but the underlying cause will remain and potentially worsen over time due to the stimulant itself becoming an obstruction to delta wave sleep periods. Lifestyle changes involving reduced stress, more exercise (especially for overweight persons experiencing EDS caused by sleep apnea and snoring) and less stimulant intake (such as coffee and nicotine) are likely to be ideal forms of assistive treatment. Some people with narcolepsy have a [[nocturnal]] body clock and are helped by selecting an occupation that properly coincides with their body's natural sleep cycle (such as sleeping in the day and working at night). This allows sufferers to avoid the need to force themselves into the more common 9 to 5 schedule that their body is unable to maintain, and avoids the need to take stimulants to remain active during the times when their bodies are inclined to rest.
-In addition to drug therapy, an important part of treatment is scheduling short naps (10 to 15 minutes) two to three times per day to help control excessive daytime sleepiness and help the person stay as alert as possible. Daytime naps are not a replacement for nighttime sleep, especially if a person's body is natively inclined towards a nocturnal life cycle. Ongoing communication between the health care provider, patient, and the patient's family members is important for optimal management of narcolepsy.
-Finally, a recent study reported that transplantation of hypocretin neurons into the [[pontine reticular formation]] in rats is feasible, indicating the development of alternative therapeutic strategies in addition to pharmacological interventions.<ref name="fn5">{{cite journal |author=Arias-Carrión O, Murillo-Rodriguez E, Xu M, Blanco-Centurion C, Drucker-Colín R, Shiromani PJ |title=Transplantation of hypocretin neurons into the pontine reticular formation: preliminary results |journal=Sleep |volume=27 |issue=8 |pages=1465–70 |year=2004 |month=December |pmid=15683135 |pmc=1201562}}</ref>
-==Epidemiology==
-It is estimated that as many as 3 million people worldwide are affected by narcolepsy. In the [[United States]], it is estimated that this condition afflicts as many as 200,000 Americans,<ref name=nhlbi>{{cite web |url=http://www.nhlbi.nih.gov/health/dci/Diseases/nar/nar_who.html |title=Who Is At Risk for Narcolepsy?}}</ref> but fewer than 50,000 are diagnosed. It is as widespread as [[Parkinson's disease]] or [[multiple sclerosis]] and more prevalent than [[cystic fibrosis]], but it is less well known. Narcolepsy is often mistaken for [[clinical depression|depression]], [[epilepsy]], or the [[adverse effect (medicine)|side effects]] of medications. It can also be mistaken for poor sleeping habits, recreational drug use, or laziness. Narcolepsy can occur in both men and women at any age, although its symptoms are usually first noticed in teenagers or young adults. There is strong evidence that narcolepsy may run in families; 8 to 12 percent of people with narcolepsy have a close relative with this neurologic disorder.{{Citation needed|date=August 2009}}
-Narcolepsy has its typical onset in [[adolescence]] and young adulthood. There is an average 15-year delay between onset and correct [[diagnosis]] which may contribute substantially to the disabling features of the disorder. Cognitive, educational, occupational, and psychosocial problems associated with the excessive daytime sleepiness of narcolepsy have been documented. For these to occur in the crucial teen years when education, development of self-image, and development of occupational choice are taking place is especially damaging. While cognitive impairment does occur, it may only be a reflection of the excessive daytime somnolence.
-The prevalence of narcolepsy is about 1 per 2,000 persons.<ref name=nhlbi/> It is a reason for patient visits to sleep disorder centers, and with its onset in adolescence, it is also a major cause of learning difficulty and absenteeism from school. Normal teenagers often already experience excessive daytime sleepiness because of a maturational increase in physiological sleep tendency accentuated by multiple educational and social pressures; this may be disabling with the addition of narcolepsy symptoms in susceptible teenagers. In clinical practice, the differentiation between narcolepsy and other conditions characterized by excessive somnolence may be difficult. Treatment options are currently limited. There is a paucity in the literature of controlled [[double-blind]] studies of possible effective drugs or other forms of therapy. Mechanisms of action of some of the few available therapeutic agents have been explored but detailed studies of mechanisms of action are needed before new classes of therapeutic agents can be developed. Narcolepsy is an underdiagnosed condition in the general population. This is partly because its severity varies from obvious to barely noticeable. Some people with narcolepsy do not suffer from loss of muscle control. Others may only feel sleepy in the evenings.
-==Famous people with narcolepsy==
-* [[Jimmy Kimmel]], TV host<ref>{{cite news|url=http://www.nytimes.com/2002/11/03/magazine/in-the-land-of-the-insomniac-the-narcoleptic-wants-to-be-king.html|title=In The Land Of The Insomniac The Narcoleptic Wants To Be King|author=Carter, Bill|publisher=''[[New York Times]]''|date=November 3, 2003|accessdate=2009-12-11}}</ref>
-==Society and culture==
-<!--Please see discussion in [Talk:Narcolepsy#Portrayal of narcolepsy in pop culture] before adding additional items to this section!-->
-Depictions of the disorder in fiction and pop culture can range greatly in the accuracy of how they depict the symptoms. Narcolepsy is often depicted in an exaggerated fashion in comedy films or TV shows. In the movie ''[[Rat Race (film)|Rat Race]]'', one of the main characters (Enrico Pollini, played by [[Rowan Atkinson]]) has narcolepsy.
-''The Little Sleep'', a detective novel by [[Paul G. Tremblay|Paul Tremblay]], portrayed the main character, Mark G. as having narcolepsy. The character deals with daily, even hourly frustrations due to the general cognitive fog, not being able to trust his own memory and even not being able to drive. Mark shares the frustration felt by many with narcolepsy, that his disease is not taken seriously and that he is "the punch line in a joke".
-In [[Gus Van Sant]]'s independent, art house drama ''[[My Own Private Idaho]]'' (1991) the lead character, Mike Waters (played by [[River Phoenix]]) has narcolepsy.  In the opening scene, a dictionary definition of the condition is presented on screen.  Phoenix's character's narcolepic episodes are used as a transition tool; transporting the characters from place to place throughout the course of the film and are interpreted with dream-like sequences of time lapsed skies, barns falling from the air and salmon swimming upstream.  The character's seizures are brought on by stressful situations, which come frequently as he is a male hustler by profession.
-In [[Hill Street Blues]], one of the minor recurring characters was Vic Hitler, the "narcoleptic comedian". He would suddenly fall asleep at inopportune moments, including while performing on stage.
-In ''Homestuck'' on [[MS Paint Adventures|mspaintadventures.com]], one of the main characters, Jade Harley, has narcolepsy. While sleeping, however, she can use a robot to interact with the world, albeit in a dream state.
-==See also==
-* [[Caffeine-induced sleep disorder]]
-* [[Cataplexy]]
-* [[Dyssomnia]]
-* [[Orexin]]
-* [[Microsleep]]
-* [[List of people with narcolepsy]]
-* [[Sleep medicine]]
-* [[Sleep inertia]]
-==References==
-{{Reflist|2}}
-==Sources==
-* {{cite journal |last=Mitler |first=M.M. |title=Relative Efficacy of Drugs for the treatment of Sleepiness in Narcolepsy |journal=Sleep |volume=14 |issue=3 |year=1991 |month=June |pages=218 |pmid=1680245 |last2=Hajdukovic |first2=R |pmc=2246380}}
-* {{cite journal |last=Chabas |first=D |title=The Genetics of Narcolepsy |journal=Annual Review of Genomics & Human Genetics |volume=4 |year=2003 |month=October |page=459 |pmid= 14527309 |doi=10.1146/annurev.genom.4.070802.110432 |last2=Taheri |first2=S |last3=Renier |first3=C |last4=Mignot |first4=E}}
-* {{cite journal |author=Smith AJ, Jackson MW, Neufing P, McEvoy RD, Gordon TP |title=A functional autoantibody in narcolepsy |journal=Lancet |volume=364 |issue=9451 |pages=2122–4 |year=2004 |pmid=15589310 |doi=10.1016/S0140-6736(04)17553-3 |url=http://linkinghub.elsevier.com/retrieve/pii/S0140673604175533}}
-==External links==
-{{External links|date=September 2010}}
-* [http://med.stanford.edu/school/Psychiatry/narcolepsy/ Stanford University: Center for Narcolepsy]
-* [http://www.narcolepsynetwork.org Narcolepsy Network Organization]
-* [http://www.ninds.nih.gov/disorders/narcolepsy/detail_narcolepsy.htm Narcolepsy Fact Sheet: National Institute of Neurological Disorders and Stroke]
-* http://www.narcolepsy.org.uk/index_html
-* [http://www.sleepfoundation.org/site/c.huIXKjM0IxF/b.2422635/k.4492/Ask_the_Sleep_Expert_Narcolepsy_and_Cataplexy.htm Read about Narcolepsy in the Sleeptionary]
-* [http://www.rare-disorders.com/narcolepsy.html What is Narcolepsy]
-* [http://www.helpguide.org/life/narcolepsy_symptom_causes_treatments.htm Narcolepsy: Symptoms, Causes, Diagnosis and Treatment]
-* [http://www.asktheneurologist.com/narcolepsy.html Narcolepsy & Cataplexy videos and case study]
-* [http://www.journalsleep.org/Articles/270802.pdf Transplantation of hypocretin neurons into the pontine reticular formation: preliminary results]
-* [http://www.sleepfoundation.org/site/apps/nlnet/content3.aspx?c=huIXKjM0IxF&b=2462667&content_id=%7BBB9407DE-75D4-44AC-8A7D-56592A368A80%7D&notoc=1 Living With Narcolepsy]
-* [http://www.sleepbettertips.com/insomnia-101/narcolepsy-linked-to-immune-system-problem Narcolepsy Linked to Immune System Problem]
-* [http://www.youtube.com/watch?v=siYsh2gp_0E Video] explaining that narcolepsy is an autoimmune disorder.
-{{Diseases of the nervous system}}
-{{SleepSeries2}}
-[[Category:Sleep]]
-[[Category:Sleep disorders]]
-[[af:Narkolepsie]]
-[[ar:ناركوليبسي]]
-[[bg:Нарколепсия]]
-[[ca:Narcolèpsia]]
-[[cs:Narkolepsie]]
-[[da:Narkolepsi]]
-[[de:Narkolepsie]]
-[[et:Narkolepsia]]
-[[el:Ναρκοληψία]]
-[[es:Narcolepsia]]
-[[fa:نارکولپسی]]
-[[fr:Narcolepsie]]
-[[ko:기면증]]
-[[id:Narkolepsi]]
-[[is:Drómasýki]]
-[[it:Narcolessia]]
-[[he:נרקולפסיה]]
-[[lt:Narkolepsija]]
-[[nl:Narcolepsie]]
-[[ja:ナルコレプシー]]
-[[no:Narkolepsi]]
-[[pl:Narkolepsja]]
-[[pt:Narcolepsia]]
-[[ru:Нарколепсия]]
-[[simple:Narcolepsy]]
-[[sk:Narkolepsia]]
-[[fi:Narkolepsia]]
-[[sv:Narkolepsi]]
-[[tr:Narkolepsi]]
-[[zh:發作性嗜睡病]]