Narcolepsy is a long-term neurological condition that impairs the brain's regulation of sleep-wake cycles. Those affected by narcolepsy often feel refreshed upon waking but then struggle with excessive daytime sleepiness. Additionally, many people with narcolepsy suffer from irregular and disrupted sleep patterns, frequently waking up during the night.¹

This rare brain disorder is caused by a selective loss or malfunction of lateral hypothalamic or orexin (also known as hypocretin) neurons. Excessive daytime sleepiness and cataplexy, along with sleep-wake symptoms such as hallucinations, sleep paralysis, and disrupted sleep, are the hallmarks of narcolepsy type 1 (NT1). The following clinical characteristics, which are backed by biomarkers, are used to make the diagnosis: the presence of rapid eye movement sleep phases immediately after the initiation of sleep, a deficit of orexin in the CSF fluid, and HLA-DQB1*06:02 positive genetic marker.²

Throughout the world, narcolepsy is still remarkably under- or misdiagnosed. The number of Americans suffering from narcolepsy is estimated to be between 135,000 and 200,000 people, according to the National Institutes of Health (NIH). However, this figure may be larger because of the proportion of patients who either do not seek medical attention for their symptoms or who are initially misdiagnosed.³

Symptoms of narcolepsy

Although narcolepsy has four primary symptoms, not every person who has the illness has them all. These four signs and symptoms are:

• Excessive daytime drowsiness, a hallmark symptom experienced by all narcoleptics, is often colloquially referred to as "sleep attacks" by both experts and individuals with the condition
• Abrupt muscle weakness, known as cataplexy, can range from mild effects to significant muscle weakness
• Hallucinations that accompany sleep onset or upon waking are common occurrences in narcolepsy.
• Sleep paralysis, wherein individuals wake up partially or remain immobile, is another prevalent symptom of narcolepsy⁴

Diagnosis of narcolepsy

If you experience sudden loss of muscular tone, cataplexy, and excessive daytime sleepiness, your doctor may suspect narcolepsy. You will probably be referred to a sleep specialist by your physician. For a thorough sleep investigation and formal diagnosis, an overnight visit to a sleep centre is required.⁵

Ruling out other conditions

The symptoms of narcolepsy may resemble those of other disorders, making a diagnosis challenging. Examples of these illnesses include:

• Sleep apnea 
• Epilepsy
• Depression 
• Hypothyroidism (An underactive thyroid gland)
• A history of head trauma

The adverse effects of several medications can occasionally also result in excessive daytime sleepiness. To help rule out other disorders that might be causing your symptoms, your general practitioner may order a number of tests. For instance, you might have blood pressure monitoring, blood testing, and physical examinations.⁶

Sleep analysis

If your doctor suspects narcolepsy, they may refer you to a sleep specialist who will assess your sleeping patterns. Various methods can be employed to study your sleep, enabling the specialist to make an accurate diagnosis.

Epworth sleepiness scale

A questionnaire called the Epworth Sleepiness Scale is used to determine your likelihood of falling asleep throughout various activities. To determine whether to send you to a sleep specialist, your general practitioner will review the findings. You will be asked to rank how likely it is that you will fall asleep when reading, watching television, and driving.  If your score is 10 or below, you are as sleepy during the day as the average person. You have a heightened level of daytime sleepiness if your score is 11 or above. Your doctor will most likely refer you to a sleep specialist for additional testing if this is the case.

Polysomnography

A specialised sleep centre will do polysomnography, which is an examination of your sleep. Typically, you have to spend the night at the sleep clinic so that your sleeping habits may be examined.  Your body will be tracked throughout the night by means of electrodes and bands applied to various places of your body while you sleep. In addition, sensors will be affixed to your legs, and a finger sensor will detect oxygen levels.

During polysomnography, a variety of tests will be performed, such as: 

• Electroencephalography (EEG), which tracks brain waves
• Electrooculography, which tracks the movements of the eyes
• Electromyography (EMG), which tracks the tone of your muscles through recordings of your chest and abdomen
• recordings of the airflow passing via your nose and mouth 
• Pulse oximetry, which assesses blood oxygen levels and heart rate
• ECG, or electrocardiography, which traces the electrical activity of your heart

It is also possible to record sound and visuals using video and sound recording equipment. An expert will review your test findings after you've gone to sleep to see if your breathing, muscular and eye movements, as well as your brain wave activity, are all within typical ranges.⁶

Multiple sleep latency test

The multiple sleep latency test (MSLT) is a procedure used to measure the time it takes for you to fall asleep during the day. This test could come after polysomnography. Throughout the day, you will be required to take multiple naps and an expert will evaluate how fast and effortlessly you fall asleep. If you have narcolepsy, you will typically have no trouble falling asleep and will quickly reach rapid eye movement (REM) sleep. To determine whether you carry the narcolepsy-associated genetic marker HLA DQB * 0602, you might also need to undergo a blood test. While a positive test confirms a diagnosis, it is not a guarantee as 30% of individuals without narcolepsy have the same genetic signature.⁷

Measuring hypocretin (orexin) levels

A lack of hypocretin (sometimes referred to as orexin) a brain neurotransmitter that regulates sleep, is frequently associated with narcolepsy. Studies have indicated that narcolepsy can be accurately diagnosed by assessing the amount of hypocretin in the cerebrospinal fluid, which surrounds the brain and spinal cord. A lumbar puncture is a medical procedure where a sample of cerebrospinal fluid is extracted using a needle to assess the level of hypocretin in your body. Specialists in sleep disorders are increasingly using this test to aid in diagnosis.⁸

Treatment options for narcolepsy

Although there isn't a cure for narcolepsy, you can control the symptoms with medication and a change in lifestyle.

• Stimulants: The main treatment for narcolepsy is medication that stimulates the central nervous system, which helps patients stay awake during the day. Your physician might advise using armodafinil (Nuvigil) or modafinil (Provigil). These medications don't lead to addictions the way earlier stimulants did. Additionally, they don't provide the same highs and lows as more traditional stimulants. Although they are rare, side effects can include anxiety, nausea, or headaches
• Serotonin and norepinephrine reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs): REM sleep is suppressed by these medications. Physicians prescribe these medications to treat cataplexy, sleep paralysis, and hallucinations. Prozac and Zoloft are examples of this type of medication. Insomnia, weight gain, and digestive issues are possible side effects
• Tricyclic antidepressants: Cataplexy can be treated with these older antidepressants. However, they may have adverse effects like lightheadedness and a dry mouth. Protriptyline, imipramine (Tofranil), and clomipramine (Anafranil) are some of these medications
• Sodium oxy-bate (Xyrem) and oxy-bate salts (Xywav): These medications are effective in alleviating cataplexy. They aid in enhancing nocturnal sleep, which is frequently inadequate in narcolepsy. They might also aid in regulating drowsiness during the day. Two dosages are taken: one right before bed and one up to four hours later^4,9,10

Side effects from these medications include nausea, wetting the bed, and sleepwalking. When combined with alcohol, narcotic painkillers, or other sleeping pills, they can cause death, coma, or difficulty breathing.

Behavioural and lifestyle modifications

Sleep Hygiene
Establishing proper sleep hygiene is essential for managing narcolepsy symptoms. This involves maintaining a consistent sleep schedule and avoiding stimulants before bedtime. Sodium oxybate can improve nocturnal sleep, highlighting the importance of quality rest. Actigraphy, which tracks sleep patterns, can provide objective data for both patients and clinicians, helping assess treatment effectiveness and guide management strategies.

Strategic Napping
Taking brief naps of 15 to 20 minutes, two or three times a day helps reduce excessive daytime sleepiness (EDS) in narcolepsy patients. Longer naps may worsen sleepiness, so timing is key. While naps offer benefits, they can be difficult to incorporate into daily life due to work and family commitments, which may also lead to financial challenges.

Sleep Logs
A sleep log that tracks sleep onset, duration, wakefulness, and nighttime awakenings is useful in diagnosing and managing narcolepsy. Family members and patients can record this data, which helps clinicians identify sleep patterns and, when actigraphy isn’t available, form a more accurate diagnosis and treatment plan.¹²

Summary

Narcolepsy is a persistent neurological condition impacting sleep-wake cycles and presents with symptoms like excessive daytime sleepiness, cataplexy, and disrupted night sleep. The diagnosis includes sleep studies such as polysomnography and the multiple sleep latency test, with hypocretin level assessment being a crucial indicator. Effective treatment integrates medications including stimulants, SSRIs, SNRIs, tricyclic antidepressants, and sodium oxy-bate along with behavioural and lifestyle changes, such as strategic napping and proper sleep hygiene. Comprehensive care is essential, involving precise diagnosis, personalized treatment plans, and ongoing patient monitoring. Continued research and increased awareness are crucial for improving understanding, diagnosis, and treatment, thereby enhancing the quality of life for individuals with narcolepsy.