Sleep is a physical and mental resting state in which a person becomes relatively unconscious. Narcolepsy is a neurological chronic sleep disorder that characterized by the inability of the brain to control sleep-wake cycles. Narcolepsy is the 4th most common sleep disorder; it affects 1 in 2,000 people in the United States of America. People with narcolepsy experience excessive daytime sleepiness, sleep attacks, sleep paralysis, hallucinations and in some cases, episodes of cataplexy are observed. Narcoleptic may taste the several episodes of uncontrollable sleepiness is usually seen after meals and even narcoleptic faces inappropriate sleepiness during day time and last for about fifteen minutes also seen. Although it is not fatal, it still has serious repercussions if the situation gets worse. Narcolepsy has devastating impact on patients in many ways in their daily activities like working abilities and social functioning even sometimes leads to total paralysis, leaving the patients to suffer for the rest of their lives.
While the exact cause of narcolepsy is idiopathic(unknown). But the possible causes of narcolepsy may include
- Low Levels of Hypocretin – Hypocretin or Orexin is a neuropeptide(Neurotransmitter) responsible for arousal and wakefulness. In some people due to auto-immune response, the hypocretin producing cells in the brain are destroyed, which leads to low levels of hypocretin. This abnormality apparently contributes to the narcoleptic symptom development.
- Secondary Narcolepsy – Sometimes Narcolepsy can be caused by an underlying condition such as head injury, brain tumor, multiple sclerosis, and encephalitis which may damage the areas of the brain that produce hypocretin. This type of Narcolepsy is termed as secondary narcolepsy.
Signs and Symptoms
- Excessive Daytime Sleepiness (EDS) – EDS involves an irresistible urge to sleep without warning, anytime, anywhere during the day. When EDS is associated with narcolepsy it can feel like you are tired all the time. People with EDS report mental fuzziness, memory lapses, lack of energy, a depressed mood, and extreme exhaustion.
- Cataplexy – This condition causes sudden temporary loss of voluntary muscle tone accompanied by full conscious awareness, triggered by strong emotions such as laughter, anger, and surprise. The loss of muscle tone that occurs may range from slurred speech, impaired eyesight to total body collapse. Mild cataplexy generally lasts less than 2 minutes and severe cataplexy persists up to 30 minutes. It is thought that 75% of narcoleptic patients experience cataplexy.
- Sleep Paralysis – In this people often experience a temporary inability to move or speak while falling asleep or waking up. During an episode of sleep paralysis, you may feel like you can’t breathe and can be a frightening experience. The length of an episode can vary from few seconds to several minutes. Sleep paralysis is often accompanied by hallucinations.
- Hallucinations – Narcoleptic patients experience vivid and frightening hallucinations at sleep onset known as hypnagogic hallucinations. The most common hallucinations observed are, the presence of someone or something in the bedroom, being caught in the fire or flying through the air. Generally, the hallucinations are visual but sometimes may also involve other senses as sound, touch smell, and taste.
The diagnosis of narcolepsy can be difficult sometimes because similar symptoms are observed in other health conditions such as sleep apnea, depression, and epilepsy. Some of the general tests carried out for the diagnosis of narcolepsy include
- Epworth Sleepiness Scale – Epworth Sleepiness Scale is a questionnaire which helps in diagnosing sleep disorders and is used to measure daytime sleepiness. A score of 10 or below indicates a normal level of daytime sleepiness and a score of 11 or above indicates an increased level of daytime sleepiness.
- Polysomnography – This investigation is carried out overnight at a sleep centre. It helps in assessing your sleeping patterns and movement during your sleep. Your body is carefully monitored with the help of electrodes, bands, and sensors placed on several parts of the body. Several other tests carried out during polysomnography include
- Multiple Sleep Latency Test – Generally, this test is performed after polysomnography. This test is used to calculate how long does it take for a narcoleptic person to fall asleep during day time. Usually, people with narcolepsy fall asleep easily and enter REM phase very quickly.
- Hypocretin (Orexin) Levels – People suffering from Narcolepsy show reduced levels of hypocretin. Hypocretin is a brain chemical generally found the in the cerebrospinal fluid surrounding the brain and spinal cord It regulates sleep, especially promotes wakefulness. To measure hypocretin levels, a sample of cerebrospinal fluid is removed by lumbar puncture method and tested.
There is no complete cure for narcolepsy. With proper diagnosis and timely treatment narcoleptic symptoms can be controlled
- Antidepressants – Antidepressant drugs helps in treating abnormal REM sleep. Some antidepressants used are
- Serotonin-noradrenaline reuptake inhibitors – SNRIs (Venlafaxine).
- Selective serotonin reuptake inhibitors – SSRIs (Femoxetine, Fluoxetine, and Citalopram).
- Tricyclic Antidepressants – TCAs (Imipramine, Chlomipramine).
- Stimulants – These drugs help you to stay awake by stimulating your central nervous system. Usually taken as tablets, most commonly used stimulants include modafinil, dexamphetamine, and methylphenidate.
- Sodium Oxybate – It is a liquid sedative that should be taken during night time, 2-3 hours after having a meal. It helps in relieving cataplexy and excessive daytime sleepiness. But serious safety concerns to be taken while using it, avoid drinking alcohol, driving and other activities which require mental alertness.
- Xyrem – Newly approved medication called XYREM is used to treat cataplexy. The action of the xyrem helps to get a better sleep at night time and also it reduces the day time sleep duration.
The most commonly observed side effects by using the above medication include nausea, irritability, headache, dry mouth, constipation, dizziness, drowsiness, blurred vision and etc.,
- Consume a balanced diet.
- Plan and follow the sleep schedule.
- Take frequent short naps during day time.
- Exercise regularly.
- Manage stress.
- Practice Yoga/Meditation.
- Avoid heavy meals; switch to small and frequent meals.
- Avoid using nicotine.
- Say no to caffeine and alcoholic beverages before bed time