For US Patients and Their Support Networks
IT TAKES
knowing that a loss of orexin is the underlying cause to understand
MY NARCOLEPSY TYPE 1
—JUSTICE, living with NT1
WHAT IS NARCOLEPSY TYPE 1 (NT1)?
Narcolepsy type 1 is a chronic neurological condition that’s caused by a loss of a brain chemical known as orexin
Orexin (also known as hypocretin) is a key brain chemical that regulates sleep and wakefulness, while also playing an important role in attention, mood, muscle control, and appetite.
In NT1, disrupted orexin signaling affects many areas of the brain.
Click each area to learn how this signal loss impacts key functions in the body.
Attention
A loss of orexin signaling can affect your ability to stay alert and maintain attention for long periods of time.
Cognition
People with NT1 may experience difficulties with cognition such as memory, learning, and concentration. For some people this may feel like “brain fog”.
Sleep/Wakefulness
A lack of orexin signaling disrupts the brain’s ability to stabilize the switch between sleep and wake, causing them to blur together. As a result, you may feel like you’re never fully rested, no matter how much sleep you get.
Mood
A loss of orexin can affect your mood and how you manage emotions, which may also cause feelings of anxiety and/or depression.
Muscle Tone
A lack of orexin allows for parts of the dream stage of sleep, including loss of muscle tone, to happen when awake. This can cause episodes of cataplexy, a sudden muscle weakness triggered by strong emotions like laughter or anger. Cataplexy can range from a partial episode, like drooping facial muscles, to a full-body collapse.
Adapted from Toor B, et al. Front Neurol Neurosci. 2021, De Luca R, et al. Nat Commun. 2022, Sakurai T. Nat Rev Neurosci. 2007, and Mahoney CE, et al.
Nat Rev Neurosci. 2019.
Depiction is for illustrative purposes.
Orexin regulates activity in the sleep–wake system, acting like a stabilizer for the brain’s “switch” between sleep and wake. It helps the body stay awake during the day and regulate sleep at night. In NT1, a loss of orexin disrupts orexin signaling, which affects the brain’s ability to stabilize the switch between sleep and wake. This causes them to blur together throughout the day and night. This can mean you never feel well rested, no matter how much sleep you get.
Disrupted orexin signaling also affects how important brain chemicals like dopamine, serotonin, histamine, and more work in your body. This is thought to cause an imbalance in energy, cognition, and mood, and can lead to cataplexy, a sudden muscle weakness triggered by strong emotions like laughter or anger.
What are the differences between narcolepsy types 1 and 2?
Want to continue your NT1 and orexin education?
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How orexin works
While people without NT1 have normal levels of orexin, people with NT1 experience a significant loss of it. Orexin works by sending signals in your brain that help your body regulate essential functions. When there’s a lack of orexin, this signaling gets disrupted, making it harder for the body to regulate various processes, and in turn making everyday activities more challenging. Let’s explore what can be affected when orexin signaling isn’t working properly.
Orexin loss affects:
The history of narcolepsy
Our knowledge of narcolepsy has always been evolving. It has shifted particularly over the last 2 decades, as scientists have been able to identify the underlying cause of NT1. Since then, we have been able to understand more about the true impact of NT1 on daily life.
Late 19th century
First clinical description of narcolepsy
1957
REM abnormalities discovered in people with narcolepsy
2000
Discovery that a loss of orexin is what causes NT1
2014
Classification of NT1 vs NT2 based on orexin deficiency and presence of cataplexy
REM=rapid eye movement.
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As I got more educated and further along in my journey after I was diagnosed, I’m like, it isn’t my fault. It’s something going on with my brain.
—TARA, living with NT1
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