Advancements in the understanding of narcolepsy are happening. Sign up now »

There’s More to Know About Narcolepsy

Know Narcolepsy seeks to improve the lives of people living with narcolepsy by advancing the ways we understand the neurobiology of sleep and wakefulness, the pathophysiology of narcolepsy, and the impact of symptoms.

Ongoing symptoms can have a significant impact, and managing narcolepsy in clinical practice can be challenging.1-3

Know more about:
Clipboard Icon

The various manifestations of narcolepsy signs and symptoms.

Recognize »
Sleep Wake Stability Icon

Narcolepsy as a disorder of sleep-wake state instability.

Learn more »
Histamine Icon

The role of histamine in promoting and stabilizing wakefulness.

Discover »
Empty Folder Icon

Recognizing ongoing symptoms of narcolepsy.

Know what to ask »
Hcp Scammell Histamine Video
Watch Video

Exploring Histamine in Sleep-Wake State Stability

Thomas Scammell, MD, from Beth Israel Deaconess Medical Center, Boston Children's Hospital, and Harvard Medical School, discusses key data from several animal studies that support why histamine plays an important role in disorders characterized by sleep-wake state instability, such as narcolepsy.6,7

The Neurobiology of Normal Sleep and Wakefulness
Watch Video

The Neurobiology of Normal Sleep and Wakefulness

Optimal health and cognitive function are due in part to a coordinated sleep-wake system that regulates three distinct and stable states of sleep and wakefulness.7-11

The Pathophysiology of Narcolepsy
Watch Video

The Pathophysiology of Narcolepsy

Discover how hypocretin loss can cause insufficient activation of histamine and other wake-promoting neurons and insufficient inhibition of non-REM sleep–promoting neurons and REM sleep–promoting neurons, leading to sleep-wake state instability.7,10,12

H10 MOD Video 02 28 20
Watch Video

The Role of Histamine in Sleep and Wakefulness

Learn more about histamine neurons, which originate in the hypothalamus, a critical control center for sleep-wake state stability.7,10,13

Hcp Scammell Histamine Video

Exploring Histamine in Sleep-Wake State Stability

The Neurobiology of Normal Sleep and Wakefulness

The Neurobiology of Normal Sleep and Wakefulness

The Pathophysiology of Narcolepsy

The Pathophysiology of Narcolepsy

H10 MOD Video 02 28 20

The Role of Histamine in Sleep and Wakefulness

  1. American Academy of Sleep Medicine. International Classification of Sleep Disorders. 3rd ed. Darien, IL: American Academy of Sleep Medicine; 2014.
  2. Ahmed I, Thorpy M. Clinical features, diagnosis and treatment of narcolepsy. Clin Chest Med. 2010;31(2):371-381.
  3. Thorpy MJ, Dauvilliers Y. Clinical and practical considerations in the pharmacologic management of narcolepsy. Sleep Med. 2015;16(1):9-18.
  4. Overeem S. The clinical features of cataplexy. In: Baumann CR, Bassetti CL, Scammell TE, eds. Narcolepsy: Pathophysiology, Diagnosis, and Treatment. Springer-Verlag New York; 2011:283-290.
  5. Ahmed IM, Thorpy MJ. Clinical evaluation of the patient with excessive sleepiness. In: Thorpy MJ, Billiard M, eds. Sleepiness: Causes, Consequences and Treatment. Cambridge University Press; 2011: 36-47.
  6. Haas HL, Sergeeva OA, Selbach O. Histamine in the nervous system. Physiol Rev. 2008;88(3):1183-1241.
  7. España RA, Scammell TE. Sleep neurobiology from a clinical perspective. Sleep. 2011;34(7):845-858.
  8. Schwartz JR, Roth T. Neurophysiology of sleep and wakefulness: basic science and clinical implications. Curr Neuropharmacol. 2008;6(4):367-378.
  9. Brown RE, Basheer R, McKenna JT, Strecker RE, McCarley RW. Control of sleep and wakefulness. Physiol Rev. 2012;92(3):1087-1187.
  10. Scammell TE, Arrigoni E, Lipton JO. Neural circuitry of wakefulness and sleep. Neuron. 2017;93(4):747-765.
  11. Scammell TE. The neurobiology, diagnosis, and treatment of narcolepsy. Ann Neurol. 2003;53(2):154-166.
  12. Scammell TE. Narcolepsy. N Engl J Med. 2015;373(27):2654-2662.
  13. Shan L, Dauvilliers Y, Siegel JM. Interactions of the histamine and hypocretin systems in CNS disorders. Nat Rev Neurol. 2015;11(7):401-413.

Performance of routine tasks without awareness.

Sudden and brief loss of muscle tone, often triggered by strong emotions or certain situations. Narcolepsy with cataplexy is known as narcolepsy type 1.

Complete collapse to the ground; all skeletal muscles are involved.

Only certain muscle groups are involved.

Biological clock mechanism that regulates the 24-hour cycle in the physiological processes of living beings. It is controlled in part by the SCN in the hypothalamus and is affected by the daily light-dark cycle.

Frequent awakenings and inappropriate transitions between states of sleep and wakefulness during nighttime sleep.

The inability to stay awake and alert during the day.

A neurotransmitter in the brain that supports wakefulness.

Vivid, realistic, and frightening dream-like events that occur when falling asleep.

A neuropeptide that supports wakefulness and helps suppress non-REM sleep and REM sleep.

Primary brain region for regulating the timing of sleep-wake states.

Unintentionally falling asleep due to excessive daytime sleepiness. Also known as “sleep attacks.”

Brief, unintentional lapses into sleep, or loss of awareness.

A validated objective measure of the tendency to fall asleep in quiet situations.

People with narcolepsy type 1 have low levels of hypocretin.

Narcolepsy without cataplexy; the cause of narcolepsy type 2 is unknown.

A state of sleep characterized by slower-frequency, more synchronized neuronal activity and decreased muscle tone. Deep stages help to restore the body.

A multiparameter test that monitors physiologic signals during sleep; used as a diagnostic tool in sleep medicine.

A state of sleep characterized by low-amplitude, fast-frequency EEG, vivid dreams, and loss of muscle tone. Normally occurs 60-90 minutes after sleep onset. Also known as “paradoxical sleep.”

Brief loss of control of voluntary muscles with retained awareness at sleep-wake transitions.

Sleep-onset REM period.