Narcolepsy (cont.)

Symptoms of narcolepsy include (each of these are discussed in detail):

• excessive daytime sleepiness
  
  
• cataplexy
  
  
• hypnagogic hallucinations
  
  
• sleep paralysis
  
  
• disturbed nocturnal sleep
  
  
• automatic behavior
  
  
• other complaints such as blurred vision, double vision, or droopy eyelids

The main symptom of narcolepsy, excessive daytime sleepiness (EDS), causes the patient to tend to fall asleep easily. This can happen in relaxed situations and also at inappropriate times and places. Patients may fall asleep while watching TV, reading a book, driving, attending a meeting, or engaging in a conversation. The daytime sleepiness is present even after normal nighttime sleep. Patients may describe this symptom as being tired, fatigued, sleepy, feeling lazy, or having low energy.

Excessive daytime sleepiness is present throughout the day but the patient, with extreme effort, may be able to resist the sleepiness for some time. Finally, it becomes overwhelming and results in a sleep episode of varied duration (seconds to minutes). In addition to daytime sleepiness, repetitive, irresistible, and unintentional sleep attacks may occur throughout the day. Excessive daytime sleepiness usually impairs a patient's functioning because it reduces motivation and vigilance, interferes with concentration and memory, and increases irritability.

Cataplexy is a sudden, temporary loss of muscle control in a person with narcolepsy. An attack of cataplexy usually is triggered by strong emotional reactions such as laughter, excitement, surprise, or anger. Factors that contribute to the attacks of cataplexy include physical fatigue, stress, and sleepiness.

Severe attacks of cataplexy may result in a complete body collapse with a fall to the ground and risk of injury. Milder forms of cataplexy are more common. These involve regional muscle groups and result in symptoms such as a drooping head, sagging jaw, slurred speech, buckling of the knees, or weakness in the arms. This muscle weakness can be quite subtle. The patient is conscious but usually unable to speak.

Cataplectic attacks may last from a few seconds to several minutes. They may vary from a few per year to numerous attacks per day that could disable the patient. Cataplexy is present in nearly 75% of patients with narcolepsy, according to the National Institutes of Health. The onset of cataplexy may coincide with the onset of excessive daytime sleepiness. However, cataplexy often develops years later. Therefore, the absence of cataplexy should not rule out the diagnosis of narcolepsy.

Source: MedicineNet.com
http://www.medicinenet.com/narcolepsy/article.htm