Narcolepsy : overview, causes, symptoms, diagnosis, treatment and prevention

Narcolepsy is a neurological disorder that affects the control of sleep and wakefulness. It is characterized by excessive sleepiness, sleep paralysis, hallucinations, and in some cases episodes of cataplexy (partial or total loss of muscle control, often triggered by a strong emotion such as laughter).

• Narcolepsy occurs equally in men and women and is thought to affect roughly 1 in 2,000 people
• In a typical sleep cycle, people enter the early stages of sleep followed by deeper sleep stages and ultimately (after about 90 minutes) rapid eye movement (REM) sleep.
• But in case of nacrolepsy, REM sleep occurs almost immediately in the sleep cycle, as well as periodically during the waking hours. It is in REM sleep that make us experience dreams and muscle paralysis, which are the common symptoms of nacroplasy.
• It usually occurs between the ages of 15 and 25, but it can become apparent at any age. In many cases, narcolepsy is undiagnosed and, therefore, untreated.

Causes of nacrolepy:

Though the causes of nacrolepsy is not completely known. But there be some thought causes, which include:

• Autoimmune disorders- The occurrence of cataplexy is most often due to the the loss of brain cells that produce hypocretin.  Although the reason for this cell loss is unknown, it appears to be linked to abnormalities in the immune system.  Body’s own immune system attacks the hypocretin brain cells which may be associated with other environmental factors.
• Family history- Nacroplasy is not a inherited disease. But in 10% cases the risk may increase due to family history.
• Brain injuries- Rarely, narcolepsy results from traumatic injury to parts of the brain that regulate wakefulness and REM sleep or from tumors and other diseases in the same regions.

Symptoms of nacrolepsy:

There may certain symptoms which can indicate nacrolepsy. It may include:

• Excessive Daytime Sleepiness (EDS)-EDS is the most common symptom of narcolepsy and usually the first symptom to appear (usually between the ages of 10-20 years old). EDS is characterized by a chronic persistence of feeling sleepy and involuntary episodes of falling asleep without warning.
• Sleep paralysis-Sleep paralysis is the inability to move or speak where one is falling asleep or waking up. During sleep paralysis the person is conscious of the surrounding, but cann’t move as the body is still in REM sleep.
• Cataplexy-Cataplexy is very similar to sleep paralysis in that there is an involuntary inability to move muscles or speak, but unlike of sleep paralysis it can occur in any time of the sleep.
• Hallucinations- Patients of nacrolepsy can experience hallucinations during waking up or during sleep onset in day. It can be vivid and often frightening.
• Disturbed nocturnal sleep-Person suffering from nacroplasy may have difficult remaining asleep in night as they have difficult remaining awake in daytime.

Diagnosis of nacrolepsy:

A preliminary study of the patient is done regarding the symptoms of EDS and cataplexy. But certain further diagnosis may be done, which include:

• Polysomnogram (PSG)-A polysomnogram is an overnight sleep study in which patients are hooked up to a variety of equipment that record brain activity, eye movements, heart rate, blood pressure, oxygen levels, body movement, and more. Certain test is used to document any abnormalities in patients sleep cycle.
• Multiple Sleep Latency Test (MSLT)-A MSLT is a sleep study that is performed during the day to measure the tendency to fall asleep during the day and how rapidly a patient fall asleep. MSLT's generally follow a Polysomnogram and record whether the patient fall asleep during the test, and if so, which stages of sleep you enter

Treatment of nacrolepsy:

• Stimulants-Drugs used to stimulate the central nervous system to help people stay awake, and certain amphetamine-like drugs are the most common stimulants given.
• Antidepressants-selective serotonin reuptake inhibitors (SSRI's) and serotonin and norepinephrine reuptake inhibitors (SNRI's) have been used to suppress REM sleep, alleviate cataplexy and sleep paralysis and hallucinations.
• Sodium Oxybate-Sodium oxybate is a strong sedative that is administered at night and helps relieve symptoms of cataplexy and EDS.  But, sodium oxybate can have serious side effects so concern of doctor is strictly recommended.
• Xyrem- It is a new medicine helps people with narcolepsy get a better night's sleep, allowing them to be less sleepy during the day. 

Nacrolepsy cannot be treated completely, use of drugs and following certain living pattern can help the patient to reduce symptoms, and control daytime sleep. Support from family and near ones may be the most effective treatment.