NARCOLEPSY

What It Is:

Narcolepsy is a chronic neurological disorder caused by the brain's inability to regulate sleep-wake cycles normally. It can cause intermittent uncontrollable episodes of falling asleep in the daytime. This is why someone with unmanaged narcolepsy may fall asleep while eating or during social activities.

Concerns:

Some of the more evident aspects of narcolepsy include:

Excessive daytime sleepiness. This is usually the first symptom to appear, and is often the most troubling.  It is an overwhelming and recurring need to sleep when you should be awake, like during school, at work or even while driving. 
Cataplexy, which is the sudden loss of muscle tone, is commonly triggered by intense emotion such as laughing, anger, surprise or fear.
Sleep paralysis. Being unable to talk or move for a brief period when falling asleep or waking up.
Hypnagogic hallucinations. These are vivid and often scary dreams and sounds experienced when falling asleep.  (People without narcolepsy may experience hypnagogic hallucinations and sleep paralysis as  well.)  
Automatic behavior. Occurs when familiar, routine or boring tasks are performed without full awareness or later memory of them.

Treatments:

Diagnosis requires a full medical history as well as the results of several different sleep studies. Medication is the first line of defense in treating narcolepsy, the goal being to approach normal alertness while minimizing side effects and disruptions to daily activities.  Changes in behavior combined with drug treatment have helped most people diagnosed narcolepsy to improve their alertness and enjoy an active, normal lifestyle.