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Narcolepsy is a clinical disorder that involves a collection of symptoms. Chronic daytime sleepiness despite appropriate sleep opportunity is absolutely required for the diagnosis. At times, the desire to sleep becomes so overwhelming that small “cat naps” are required throughout the day to feel refreshed. Individuals may also experience episodes of cataplexy (muscle weakness associated with expression of emotion), muscle paralysis during sleep-wake transitions, and dream-like images experienced when they are awake.


Circadian Rhythms

What makes one person greet the day with smiles and energy, and another hide under the covers until the last possible moment? It's a combination of genetics, the environment and our lifestyle choices, says sleep specialist Mark Wu.
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Our Experts in the News

Learn from Dr. Rachel Salas about the benefits of a "sleep buddy"

Listen to Dr. Jeff Ellenbogen discuss How Sounds Undermine Sleep

Sleeping by Example: Interview with Leading Researcher and Johns Hopkins Neurologist, Dr. Rachel Salas

A new study's surprising news about how many Americans sleepwalk

Probing the Mysteries of Brain Injury and Sleep
Find out how Hopkins researchers are investigating the brain pathway problems related to traumatic brain injury and insomnia


Out-of-State and International Patients - Find Out More


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