Rare Endocrinology News

Disease Profile

Narcolepsy

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

50/100,000

165,500

US Estimated

256,750

Europe Estimated

Age of onset

Adolescent and Adult

ageofonset-adolescent-and-adult.png

ICD-10

G47.4

Inheritance

Other names (AKA)

Gelineau's syndrome; Hypnolepsy; Narcoleptic syndrome; Paroxysmal sleep

Categories

Nervous System Diseases

Summary

Narcolepsy is a chronic brain disorder that involves poor control of sleep-wake cycles. People with narcolepsy have episodes of extreme daytime sleepiness and sudden, irresistible bouts of sleep (called "sleep attacks") that can occur at any time, and may last from seconds or minutes. Other signs and symptoms may include cataplexy (a sudden loss of muscle tone that makes a person go limp or unable to move); vivid dream-like images or hallucinations; and/or total paralysis just before falling asleep or after waking-up. Narcolepsy may have several causes, the most common being low levels of the neurotransmitter hypocretin (for various possible reasons). The disorder is usually sporadic but some cases are familial. There is no cure, but some symptoms can be managed with medicines and lifestyle changes.[1]

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Cataplexy
0002524
Excessive daytime somnolence
Excessive daytime sleepiness
More than typical sleepiness during day

[ more ]

0001262
Hallucinations
Hallucination
Sensory hallucination

[ more ]

0000738
Transient global amnesia
0010534
30%-79% of people have these symptoms
Abnormal rapid eye movement sleep
0002494
Abnormality of vision
Abnormality of sight
Vision issue

[ more ]

0000504
5%-29% of people have these symptoms
Obesity
Having too much body fat
0001513
Slurred speech
0001350
Syncope
Fainting spell
0001279
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Hypnagogic hallucinations
0002519
Hypnopompic hallucinations
0006896
Narcolepsy
0030050
Paroxysmal drowsiness
0002330

Diagnosis

Narcolepsy is often diagnosed in adolescence and young adulthood, when falling asleep suddenly in school brings the problem to attention. However, for many people with narcolepsy, the disorder is not diagnosed for up to 10-15 years after symptoms first begin. The disorder may be misdiagnosed as various other conditions or psychological problems.[2] While it is most easily recognized if all the major symptoms are reported, making the diagnosis based solely on symptoms is difficult. People often seek medical help for single symptoms that could be associated with other disorders, particularly epilepsy. In come cases, symptoms are not dramatically apparent for years.[2]

Sleep studies are an essential part of the evaluation of people with possible narcolepsy. The combination of an overnight polysomnogram (PSG) followed by a multiple sleep latency test (MSLT) can provide strongly suggestive evidence of narcolepsy, while excluding other sleep disorders. Measurement of hypocretin levels in the cerebrospinal fluid (CSF) may further help to establish the diagnosis.[3] People with narcolepsy often have extremely low levels of hypocretin in their CSF.[4] In some cases, human leukocyte antigen (HLA) typing may be helpful.[1]

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Orphanet lists international laboratories offering diagnostic testing for this condition.

    Treatment

    There is currently no cure for narcolepsy, but some of the symptoms can be managed with medications and lifestyle changes.[1]

    Most affected people improve if they maintain a regular sleep schedule, usually 7.5 to 8 hours of sleep per night. Scheduled naps during the day also may help. Other measures that may help include participating in an exercise program; receiving emotional support and career or vocational counseling; and avoiding high-risk behaviors such as alcohol and drug use, which may make symptoms worse.[3] Common-sense measures should be taken to enhance sleep quality (such as avoiding heavy meals before bed time).[1]

    Treatment with medications involves the use of central nervous system (CNS) stimulants. These medications help reduce daytime sleepiness and improve this symptom in 65-85% of affected people.[3] Two types of antidepressant drugs (tricyclics, and selective serotonin and noradrenergic reuptake inhibitors) are effective in controlling cataplexy in many people. Sodium oxybate (a strong sedative taken during the night) may also be used to treat narcolepsy.[1]

    You can view detailed information about the treatment of narcolepsy on Medscape's Web site.

    FDA-Approved Treatments

    The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

    Organizations

    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Social Networking Websites

      • RareConnect has an online community for patients and families with this condition so they can connect with others and share their experiences living with a rare disease. The project is a joint collaboration between EURORDIS (European Rare Disease Organisation) and NORD (National Organization for Rare Disorders).

        Organizations Providing General Support

          Learn more

          These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

          Where to Start

          • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
          • Genetics Home Reference (GHR) contains information on Narcolepsy. This website is maintained by the National Library of Medicine.
          • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
          • The National Heart, Lung, and Blood Institute (NHLBI) has information on this topic. NHLBI is part of the National Institutes of Health and supports research, training, and education for the prevention and treatment of heart, lung, and blood diseases.
          • The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
          • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

            In-Depth Information

            • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
            • MeSH® (Medical Subject Headings) is a terminology tool used by the National Library of Medicine. Click on the link to view information on this topic.
            • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
            • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
            • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
            • PubMed is a searchable database of medical literature and lists journal articles that discuss Narcolepsy. Click on the link to view a sample search on this topic.

              References

              1. Narcolepsy Fact Sheet. National Institute of Neurological Disorders and Stroke. January 5, 2015; https://www.ninds.nih.gov/disorders/narcolepsy/detail_narcolepsy.htm.
              2. Narcolepsy. University of Maryland Medical Center. September 18, 2013; https://umm.edu/health/medical/reports/articles/narcolepsy.
              3. Ali M Bozorg. Narcolepsy. Medscape. April 15, 2015; https://emedicine.medscape.com/article/1188433-overview.
              4. Narcolepsy. NORD. March 2, 2012; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/55/viewAbstract.

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