The classic tetrad of narcolepsy consists of excessive daytime sleepiness (EDS), cataplexy, hypnagogic hallucinations, and sleep paralysis. In very few cases it is seen that a child presents with all 4 symptoms [13].

EDS is the primary symptom of narcolepsy and must be present for at least 3 months to justify the diagnosis. In persons with narcolepsy, severe EDS leads to involuntary somnolence during activities that normally need attention, like driving, eating, or talking. Narcoleptic patient can suffer from severe and constant sleepiness, with bouts of falling asleep without any warning (i.e. sleep attacks).

Patients with narcolepsy tend to take short and refreshing naps (i.e. rapid eye movement (REM)-type naps) during the day. Sometimes dreams also accompany the daytime naps.

A significant number of narcolepsy patients have trouble sleeping at night [14]. In addition, patients may have nocturnal compulsive habits like, eating disorder in relation with sleep and smoking at night [15]. Obesity is commonly seen with narcolepsy.

Cataplexy is a brief and sudden loss of muscle tone and represents REM sleep intrusion during wakefulness. The most characteristic feature of cataplexy is that it usually is triggered by emotions (especially laughter and anger). Cataplexy is seen in about 70% of patients with narcolepsy. The presence of cataplexy along with EDS is strongly suggestive of narcolepsy.

Patients with narcolepsy may experience sleep paralysis, in which the patient is not able to move when he/she wakes up and sometimes when asleep with consciousness intact. Often hallucinations accompany it. Sleep paralysis occurs less frequently when patients sleep in uncomfortable positions. The person can be rescued from this condition by sensory stimuli, like touch or talking with that person.

Sleep-related hallucinations may be either hypnagogic (i.e. occurring at sleep onset) or hypnopompic (i.e. occurring at awakening). These hallucinations are usually vivid (dreamy) either tactile, visual or auditory in character.

At disease onset, children with narcolepsy and cataplexy may display a wide range of motor disturbances that do not corroborate with cataplexy as it is classically. The motor disturbances, can be negative (hypotonia) or active (e.g. perioral movements, dyskinetic-dystonic movements, or stereotypic movements), and are seen to settle later during the course of disease [16].

In children aged 5-10 years, inattentiveness is the most common initial complaint, followed by recurring sleepiness and later on by difficulty in morning arousal associated with aggressive behavior and abrupt falls in school [17]. These children often were misdiagnosed as having attention deficit hyperactivity disorder (ADHD), learning disability, depression, or another neurological disorder. In children aged 10-12 years, poor academic performance is a common complaint [17].

Physically, narcoleptic patients are normal.

• Excessive Daytime Sleepiness

  All have excessive daytime sleepiness. People with narcolepsy have excessive daytime sleepiness, often despite long periods of excessive sleep. [msdmanuals.com]

  Epidemiology Narcolepsy is a frequent disorder: it is the second leading cause of excessive daytime sleepiness diagnosed by sleep centers after obstructive sleep apnea. [med.stanford.edu]

  People who experience automatic behavior do not remember the activity in which they participated during sleep Excessive daytime sleepiness, which can be accompanied with inability to concentrate, excessive yawning, poor performance at work or school, [summitmedicalgroup.com]

  The main symptoms are excessive daytime sleepiness and abnormal rapid eye movement (REM) sleep. Narcolepsy is the second leading cause of excessive daytime sleepiness after obstructive sleep apnea. [medicalnewstoday.com]

• Falling

  Falling asleep suddenly may result in injury. You're at increased risk of a car accident if you fall asleep while driving. Your risk of cuts and burns is greater if you fall asleep while cooking. Obesity. [mayoclinic.org]

  During hypnagogic hallucinations, patients experience dream-like auditory or visual hallucinations, while dozing or falling asleep. [med.stanford.edu]

  Polysomnography is used as part of this test to assess how quickly people fall asleep. It detects when people fall asleep and is used to monitor the stages of sleep during the naps and to determine whether REM (dreaming) sleep occurs. [msdmanuals.com]

  It is a neurologic disorder that can cause someone to fall asleep while engaging in any activity, including working, driving, or having a conversation. [summitmedicalgroup.com]

• Hypersomnia

  NC, narcolepsy-cataplexy CBF, cerobrospinal fluid MN, monosymptomatic narcolepsy PH, primary hypersomnia MSLT, multiple sleep latency test Statistics from Altmetric.com hypocretin orexin narcolepsy primary hypersomnia Hcrt, hypocretin EDS, excessive [jnnp.bmj.com]

  There were 274 patients with narcolepsy; hypersomnia; obstructive sleep apnea; restless legs syndrome; insomnia; and atypical hypersomnia cases such as familial cases, narcolepsy without cataplexy or without HLA-DQB1*0602, recurrent hypersomnias, and [ncbi.nlm.nih.gov]

• Fatigue

  Overall, participants reported that fatigue and cognitive difficulties were their most burdensome symptoms in addition to sleepiness and cataplexy. The majority of participants reported residual daytime fatigue and/or sleepiness despite treatment. [ncbi.nlm.nih.gov]

  Fatigue Completed NCT00678691 Phase 4 armodafinil;placebo 4 Slow-wave Sleep and Daytime Functioning in Chronic Fatigue Syndrome: Effects of Sodium Oxybate Completed NCT02055898 Phase 4 Sodium Oxybate 5 The Effect of Armodafinil (Nuvigil) on Fatigue and [malacards.org]

  […] of them There are four key symptoms of narcolepsy, though people with narcolepsy often exhibit only some: Excessive daytime sleepiness (EDS) Falling asleep at inappropriate times throughout the day and/or experiencing chronic pervasive sleepiness and fatigue [narcolepsy.org.uk]

  The persons who suffer from this condition experience fatigue and may fall asleep at inappropriate times during the day. [icd9data.com]

  Improving the quality of nighttime sleep can combat EDS and help relieve persistent feelings of fatigue. [web.archive.org]

• Epilepsy

  Narcolepsy type 1 and focal epilepsy was diagnosed. Some clinical symptoms of narcolepsy (cataplexy, automatic behavior, episodes of sleep attacks) need to be carefully analyzed by EEG and video-EEG not to overlook the epilepsy. [ncbi.nlm.nih.gov]

  These effects are even more severe than the well-documented deleterious effects of epilepsy when similar criteria are used for comparison. [med.stanford.edu]

• Sleep Apnea

  Epidemiology Narcolepsy is a frequent disorder: it is the second leading cause of excessive daytime sleepiness diagnosed by sleep centers after obstructive sleep apnea. [med.stanford.edu]

  Polysomnography is now commonly done in the home to diagnose obstructive sleep apnea, but not any other sleep disorders. [msdmanuals.com]

  SUBJECTS AND METHODS: Children between 6 and 17 years of age with narcolepsy that underwent adenotonsillectomy for non-severe obstructive sleep apnea (OSA) were included. [ncbi.nlm.nih.gov]

  Obstructive Sleep Apnea/Hypopnea Syndrome, or Chronic Shift Work Sleep Disorder (With an Open-Ended Extension Period) Completed NCT00228553 Phase 3 Armodafinil 100 to 250 mg/day 25 A 1 Year Open Label, Flexible Dosage Extension Study to Assess the Safety [malacards.org]

• Diarrhea

  Rarely, mild constipation or diarrhea may occur. Fluoxetine (Prozac) given late in the day may cause insomnia. [medicinenet.com]

  The most common adverse effects are insomnia, headache, nausea, decreased appetite, and diarrhea. There are no interactions with oral contraceptives. [msdmanuals.com]

• Diplopia

  Occasionally there will be introductions of blurred vision or diplopia due to their sleepiness. Narcoleptics do not sleep longer than normal during a typical 24-hour period, but their sleep is non-restorative. [healthcentral.com]

  […] have HLA-DR2 and/or HLA-DQw1 Clinical Narcolepsy tetrad; if accompanied by cataplexy, Pt feels a sense of absolute urgency for sleep in often inappropriate situations–while standing, eating, carrying on conversations, accompanied by blurred vision, diplopia [medical-dictionary.thefreedictionary.com]

  Slurred speech and visual symptoms such as blurred vision or diplopia may be experienced. Hearing, awareness and consciousness are intact. [patient.info]

  As a consequence of sleepiness, patients may report inattention, poor memory, blurry vision, diplopia, and automatic behaviors such as driving without awareness [1–3]. 2. [hindawi.com]

• Muscle Hypotonia

  Hypotonia of mimic muscles can be confused for a severe sleepiness (MPG 19793 kb) References Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1. McKenna C, McNicholas F. [doi.org]

• Auditory Hallucination

  Later, due to auditory hallucinations she was referred to a psychiatric hospital. Her reality judgement was poor, with partial insight regarding her illness. [ncbi.nlm.nih.gov]

  Hypnagogic hallucinations — Dream-like auditory or visual hallucinations that occur while falling asleep. [medical-dictionary.thefreedictionary.com]

  Abnormal vivid auditory or visual hallucinations that occur while falling asleep are known as hypnagogic hallucinations, but the more common hypnopompic hallucinations occur upon awakening. [pulmonologyadvisor.com]

• Aggressive Behavior

  Children and adolescents with narcolepsy may struggle with emotional regulation and display aggressive behaviors that lead to social exclusion and feelings of self-loathing and shame. [wakeupnarcolepsy.org]

  While stimulants may be effective, potential side effects include dependence, aggressive behavior, and heart problems. Non-stimulant medications include modafinil and armodafinil. [web.archive.org]

  In children aged 5-10 years, inattentiveness is the most common initial complaint, followed by recurring sleepiness and later on by difficulty in morning arousal associated with aggressive behavior and abrupt falls in school. [symptoma.com]

• Mood Swings

  After failed medication attempts, stomach pains, shakes and random mood swings I stopped seeking treatment. This decision was hard for me because it meant that I had to forfeit parts of my life to my condition. [medium.com]

• Sleep Attack

  Amphetamine-like stimulant drugs are often prescribed to control drowsiness and sleep attacks. [medical-dictionary.thefreedictionary.com]

  Sometimes sleepiness occurs so suddenly and with such overwhelming power that it is referred to as a "sleep attack." Some patients have several "attacks" each day. [healthcentral.com]

  Case 2 was an 11-year-old girl presenting with recurrent episodes of myoclonic attacks simultaneously with dropping objects immediately after hearty laughs, in addition to sleep attacks, hypnagogic hallucinations, and sleep paralysis. [ncbi.nlm.nih.gov]

  Narcolepsy is a condition that causes overwhelming drowsiness and sudden attacks of sleep. It affects 1 of every 2,000 people. Symptoms often begin in young adulthood and may be hereditary. [nationaljewish.org]

• Automatic Behavior

  Narcolepsy signs and symptoms include: Automatic behavior, which can involve continuing with an activity despite being asleep. [summitmedicalgroup.com]

  Some clinical symptoms of narcolepsy (cataplexy, automatic behavior, episodes of sleep attacks) need to be carefully analyzed by EEG and video-EEG not to overlook the epilepsy. [ncbi.nlm.nih.gov]

  A condition characterized by recurrent episodes of daytime somnolence and lapses in consciousness (microsomnias) that may be associated with automatic behaviors and amnesia. [icd9data.com]

  Automatic behavior Automatic behavior is the performance of routine tasks by a person who is not consciously controlling the activity. Sometimes a person may actually fall asleep and continue an activity, but not recall having done it when awakened. [chop.edu]

• Irritability

  People who experience automatic behavior do not remember the activity in which they participated during sleep Excessive daytime sleepiness, which can be accompanied with inability to concentrate, excessive yawning, poor performance at work or school, irritability [summitmedicalgroup.com]

  Excessive daytime sleepiness presenting as chronic drowsiness or irritability could be stigmatized as laziness or misinterpreted as behavior or inattention disorder. [ncbi.nlm.nih.gov]

  This is often accompanied by aggression and irritability. Cataplexy may not be seen in all narcoleptic patients, and may take several years before becoming apparent. Furthermore, it can take on varying forms of intensity. [news-medical.net]

  Employer thinks it's an excuse, friends are irritated, I'm at my wits end. Life is spent sleeping more than awake. A. Narcolepsy cannot yet be cured. [medical-dictionary.thefreedictionary.com]

  Sleepiness doesn’t always LOOK sleepy Narcolepsy’s sleepiness may manifest as hyperactivity, irritability, moodiness, attention deficits, fogginess, or memory problems. [julieflygare.com]

• Somnolence

  A condition characterized by recurrent episodes of daytime somnolence and lapses in consciousness (microsomnias) that may be associated with automatic behaviors and amnesia. [icd9data.com]

  Narcolepsy is characterized by excessive daytime somnolence associated with sleep paralysis, hallucinations when falling asleep or awakening, and cataplexy. Early recognition of pediatric narcolepsy is essential for growth and development. [ncbi.nlm.nih.gov]

  Randomized trial of modafinil for the treatment of pathological somnolence in narcolepsy. Unlike canine models of narcolepsy, no orexin\hypocretin receptor mutations were observed. [dictionary.cambridge.org]

• Hyperactivity

  Since cholinergic hyperactivity is a feature of narcolepsy-cataplexy, we transferred IgG from nine patients with narcolepsy and nine healthy controls to mice and assessed the effect on smooth muscle contractile responses to cholinergic stimulation. [ncbi.nlm.nih.gov]

  This is mostly because symptoms associated with narcolepsy can be nonspecific and can be easily mistaken for other disorders, such as epilepsy and attention deficit hyperactivity disorder (ADHD). [news-medical.net]

Sleep studies are an essential part of the evaluation of patients with probable chances narcolepsy. An overnight polysomnogram (PSG) followed by a multiple sleep latency test (MSLT) can provide strongly suggestive evidence of narcolepsy while excluding other sleep disorders.

Human leukocyte antigen (HLA) typing may provide collateral data, but it is more useful for excluding the diagnosis by documenting that the patient does not have either DQB1*0602 or DQA1*0602.

Measurement of hypocretin (orexin) levels in the cerebrospinal fluid (CSF) may help establish the diagnosis [9]. CSF hypocretin levels lower than 110 pg/mL are included in the diagnostic criteria for narcolepsy in the second edition of the International Classification of Sleep Disorders (ICSD-2).

Imaging studies such as MRI are useful for excluding rare causes of symptomatic narcolepsy. Idiopathic narcolepsy may be seen in cases where there are structural abnormalities of the brainstem and diencephalon. MRI of brain in patients suffering from secondary narcolepsy, may show different abnormalities that can be related to the underlying cause.

• Reduced Sleep Latency

  Multiple sleep latency test showed multiple sleep onset REM periods with reduced sleep latency. When CMT1 and narcolepsy were coexist in an individual, the latter might be overlooked. [ncbi.nlm.nih.gov]

  Polysomnography usually reveals a shortened sleep latency, increased total sleep time, and, reduced sleep latency on the muliple sleep latency test. 5, 6 There is an absence of sleep onset REM periods. [jnnp.bmj.com]

  MSLT-like procedures have also been adapted to the canine species and have shown reduced sleep latency and REM latency in narcoleptic canines ( Nishino and Mignot 1997 ). [doi.org]

• HLA-DR2

  The HLA molecules are very particular in that different individuals generally carry different HLA "subtypes" (for example DR1, DR2, subtypes of HLA-DR; DQ1, DQB1*0602, subtypes of HLA-DQ). [med.stanford.edu]

  […] driving or while at work and prefer shift work as 'drowsiness' is more socially acceptable; it may also be accompanied by sleep paralysis Prevalence 1:600–Japan, 1:2400–US, 1:500, 000–Israel, ♂:♀ ratio 1:1, onset age 15– 35; 98-100% of narcoleptics have HLA-DR2 [medical-dictionary.thefreedictionary.com]

  In parallel narcolepsy studies across ethnic groups, Mignot’s lab found that it was not the initial HLA-DR2 allele that predisposed humans to narcolepsy, but another, nearby HLA gene, DQB1*0602. Humans are not like dogs. [the-scientist.com]

  Narcolepsy was first shown to be tightly associated with HLA-DR2 (ref. 3 ) and later sublocalized to DQB1 * 0602 (ref. 4 ). [doi.org]

• HLA-DQ1

  […] with HLA DR2 and HLA DQ1. [psychology.wikia.com]

Treatment of narcolepsy has two components i.e medical and auxiliary management. Good sleep hygiene is a must. Improvement is seen when the patients have a regular sleep schedule, which is generally 7.5-8 hours of sleep every night. Scheduled naps during the day also may help [18].

Pharmacologic treatment of narcolepsy involves the use of central nervous system (CNS) stimulants such as amphetamine, methylphenidate, modafinil, methamphetamine, and dextroamphetamine sulfate. With the help of these medicines daytime sleepiness can be reduced, thereby improving the symptoms in 65-85% of patients.

Tricyclic antidepressants such as protriptyline, imipramine and clomipramine, are effective for cataplexy. Sodium oxybate is highly effective for cataplexy, as it helps in improving night time sleep, which is often poor in narcolepsy. Selective serotonin reuptake inhibitors (SSRIs) or serotonin and norepinephrine reuptake inhibitors (SNRIs) suppress REM sleep, thus helping to alleviate the symptoms of cataplexy, hypnotic hallucinations and sleep paralysis. They include fluoxetine and venlafaxine.

If the disease is managed and treated properly, then patients suffering from narcolepsy can have good life at home and work too. But if not treated, then it can be psychosocially disastrous [12].

Narcoleptic children may suffer from bad performance in school, social impairment, mocked by the colleagues, and there would be flaws in various activities seen in normal childhood development.

The exact cause of narcolepsy isn't known. Narcolepsy has a genetic component and tends to run in families. An estimated 8 to 10% of people with narcolepsy have a close relative who has the disorder. Narcolepsy most likely involves a combination of genetics and one or more environmental provoking factors like infection, trauma, hormonal changes, immune system disorders, or stress.

Narcolepsy affects about 1 in 2,000 people. The prevalence of narcolepsy in the US is 0.02-0.18%, which is comparable to that of multiple sclerosis [2] [3]. The frequency among first-degree relatives is 1-2%. Narcolepsy with cataplexy affects 0.02% of adults worldwide [4].

The male-to-female ratio in narcolepsy is 1.64:1. The disease has highest peak of occurrence at 15 years and a less marked peak at 36 years.

Narcolepsy is considered to be an outcome of susceptible genes, defective neurotransmitter functioning and sensitivity, and aberrant immune modulation. Recent studies blame some human leukocyte antigen (HLA) subtypes and abnormal hypocretin (orexin) neurotransmission, that causes unexpected changes in monoamine and acetylcholine synaptic transmissions, and more accurately in the reticular activating system of the pons [5] [6].

The centrality of hypocretin transmission in the pathophysiology of narcolepsy was demonstrated when hypocretin knockout mice displayed cataplexy and sleepiness [7] [8]. Further evidence for impaired hypocretin functioning in humans was found with the discovery of low levels of hypocretin in the cerebrospinal fluid (CSF) of narcoleptic patients [9].

Subsequently, abnormal immune modulation was associated with the clinical development of narcolepsy in children in Scandinavia and Finland. It was found that the chances of narcolepsy increased to 8-12 folds in Finnish children after vaccination against the H1N1 influenza virus with a vaccine that used a potent ASO3 adjuvant. Every affected child who went through HLA typing was seen having the HLA DQB*0602 allele [10] [11].

Narcolepsy cannot be prevented but the frequency of the narcolepsy episodes can be reduced in those suffering from it by avoiding the triggering factors or the conditions that causes the attack.

Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden bouts of sleep. It is difficult for a person suffering from narcolepsy to stay awake for long periods of time, whatever be the circumstances. It is characterized by the classic tetrad of excessive sleepiness during the daytime, cataplexy, hypnotic hallucinations, and sleep paralysis. It is also known as hypnolepsy, defined as a chronic neurological disorder caused by autoimmune destruction of hypocretin-producing neurons inhibiting the brain's ability to regulate sleep-wake cycles normally.[1]

Narcolepsy is a medical disorder characterized by excessive, sudden bouts of uncontrollable sleep during the day. These patients cannot sleep well at night and a polysomnogram is used to diagnose the condition.

The condition cannot be prevented as the exact cause is not understood but the symptoms can be controlled very well lifelong with medications like antidepressants, and stimulants. It is not a fatal condition but it can lead to accidents that are life-threatening.

Patients with narcolepsy should avoid heavy meals and alcohol. Patients should take scheduled short naps and participate in an exercise programs. They must avoid driving, operating heavy machinery, or any other activity that can have detrimental effect when sleepy. In one survey, almost 75% of patients with narcolepsy reported falling asleep while driving, and 56% reported nearly having accidents. In addition to these accidents, there are various other accidents that associated with narcolepsy like burns due to coming in close contact with hot objects, cuts from handling sharp objects, and breaking things. Patients with narcolepsy with cataplexy should wear a life preserver when engaged in water activities. They should not do water activities all by themselves. They should inform and also educate others about their cataplectic attacks.

People with narcolepsy have problems with memory, thinking, and attention. They suffer from emotional and social difficulties caused by their uncontrollable sleep episodes and cataplexy. They are prone to suffer from depression, severe emotional and social dysfunction in all areas, be it work, relationships or any relaxing activity. Generally it is seen that men with narcolepsy suffer from sexual problems.

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