Narcolepsy (NAR-ko-lep-se) is a chronic neurological disorder caused by the brain’s inability to regulate sleep-wake cycles normally. At various times throughout the day, people may experience fleeting urges to sleep. If the urge becomes too overwhelming, individuals will fall asleep for periods lasting from a few seconds to several minutes. Short periods of muscle weakness or total paralysis may occur during strong emotional experiences. Narcolepsy affects people differently and some individuals have more severe symptoms than others.
Normal sleep begins with NREM sleep during which the brain waves begin to slow. Patients with narcolepsy fall immediately into REM sleep without going through the normal stages. There is a neuropeptide called hypocretin (hi-po-KREET-in) or orexin which regulates REM sleep and the ability to stay awake during the day. Scientists have discovered that people with narcolepsy have very low levels of this hormone and the cells that create it are badly damaged.
Narcolepsy affects about one out of every 2,000 people and occurs slightly more often in men than in women. It usually begins in the pre-teen years to early adulthood. Many people who have narcolepsy suffer from depression.
Symptoms of Narcolepsy
- Cataplexy or sudden loss of muscle tone. Approximately seven out of ten people who suffer from narcolepsy also have cataplexy.
- Hallucinations or delusional experiences that are vivid, often frightening. Most often the experiences are visual, but other senses can be involved. They may occur during sleep onset or during awakening.
- Excessive Daytime Sleepiness
- Sleep Paralysis or the inability to move or even speak during the onset of sleep or while waking. When these episodes occur, they usually last from a few seconds to several minutes followed by rapid return to full ability to move and speak. This sleep paralysis is very much like that which takes place during REM sleep. Many patients are actually aware of their paralysis.
- Waking up often and having trouble falling back to sleep
- Difficulty with memory
If you thnk you may have narcolepsy or cataplexy you really should see a sleep physician. It is important that you be able to provide information about your symptoms and when you began experiencing them. It is helpful if you keep a journal of your sleep patterns for at least a couple weeks. The sleep doctor will also need to know your medical history and if anyone in your family has had a sleep disorder.
Two tests that are essential in properly diagnosing narcolepsy are the Polysomnogram or PSG and the Multiple Sleep Latency Test or MSLT.
Cataplexy
Cataplexy (KAT-a-plek-se) is a symptom of narcolepsy, however, you can have narcolepsy without cataplexy.
- Cataplexy causes extreme weakness and loss of muscle control.
- Cataplexy can causes symptoms ranging from slurred speech to total body collapse.
- Strong emotions, even laughter, can trigger an episode.
- Episodes may occur several times per day.
- Episodes usually last for less than a minute.
- Patients can experience muscle twitching which is often mistaken for epilepsy.
- Patients with cataplexy may experience slurred speech and weakened eyesight, but their hearing and awareness of their surroundings will remain normal.
- Individuals with cataplexy may lose control of their facial muscles, their head may nod or drop down, or they may simply collapse and fall down. Injuries are not uncommon.
- Treatment for cataplexy is different from that of narcolepsy.