What is the Difference Between Type 1 and Type 2 Narcolepsy

Type 1 and type 2 narcolepsy are the two main types of narcolepsy. Narcolepsy causes an urge to fall asleep suddenly during the daytime.  This is a sleep disorder that is almost impossible to resist.

The key difference between type 1 and type 2 narcolepsy is the presence or absence of cataplexy. Type 1 narcolepsy is a form of narcolepsy that involves cataplexy, while type 2 narcolepsy is a form of narcolepsy that does not involve cataplexy.

CONTENTS

1. Overview and Key Difference
2. What is Type 1 Narcolepsy
3. What is Type 2 Narcolepsy
4. Similarities – Type 1 and Type 2 Narcolepsy
5. Type 1 vs Type 2 Narcolepsy in Tabular Form
6. Summary – Type 1 vs Type 2 Narcolepsy
7. FAQ – Type 1 and Type 2 Narcolepsy

What is Type 1 Narcolepsy?

Type 1 narcolepsy is not a common form of narcolepsy. This type of narcolepsy involves cataplexy. Cataplexy is a transient, sudden loss of voluntary muscle control due to a strong emotional trigger such as laughing or excitement. Cataplexy is always associated with narcolepsy. About 20% of narcolepsy cases are type 1 narcolepsy.

The age of onset for this form varies between 10 and 30 years old. However, the symptoms are lifelong. The symptoms may include day sleepiness, cataplexy, hypnagogic hallucinations, sleep paralysis, disturbed nocturnal sleep, and weight gain, especially in children. Type 1 narcolepsy is a result of a shortage of a hormone called hypocretin or orexin.

Figure 01: Screenshot of a Person in Stage N3 Sleep

Type 1 narcolepsy can be diagnosed through physical examination, polysomnography findings, low hypocretin-1 levels in cerebral spinal fluid, and genetic counselling. Furthermore, treatment options for type 1 narcolepsy comprises giving stimulants (modafinil, methylphenidate, amphetamine, pitolisant, solriamfetol), anticataplectic drugs (antidepressants) or sodium oxybate, and good sleep hygiene.

What is Type 2 Narcolepsy?

Type 2 narcolepsy form doesn’t involve cataplexy. The majority of narcolepsy cases (about 80%) are type 2 narcolepsy. The symptoms of type 2 narcolepsy include excessive daytime sleepiness, sleep paralysis, hallucinations, disturbed sleep, and automatic behaviors. It is not clear why some people have type 2 narcolepsy rather than type 1. It might involve a less severe shortfall in hypocretin, disturbances in receptors in the brain that detect the hypocretin effect, brain injury, or tumor.

Type 2 narcolepsy form can be diagnosed through physical examinations, polysomnograms, multiple sleep latency tests, and cerebrospinal fluid tests. Furthermore, treatment options for type 2 narcolepsy include medications such as modafinil and lifestyle changes.

Similarities Between Type 1 and Type 2 Narcolepsy

1. Type 1 and type 2 narcolepsy are two forms of narcolepsy.
2. These forms involve sleep disturbances and hallucinations.
3. Both forms can be diagnosed through polysomnogram.
4. Both forms can be treated by giving specific medications and lifestyle adjustments.

Difference Between Type 1 and Type 2 Narcolepsy

Definition

1. Type 1 narcolepsy is a form of narcolepsy that involves a transient, sudden loss of voluntary muscle control.
2. Type 2 narcolepsy is a form of narcolepsy that does not involve a transient, sudden loss of voluntary muscle control.

Commonness

1. Type 1 narcolepsy is less common (comprises 20% of narcolepsy cases).
2. Type 1 narcolepsy is more common (comprises 80% of narcolepsy cases).

Aetiology

1. Type 1 narcolepsy is due to a shortage of a hormone called hypocretin or orexin.
2. Type 1 narcolepsy can be due to a less severe shortfall in hypocretin, disturbances in receptors in the brain that detect hypocretin, brain injury, or tumors.

Symptoms

1. The symptoms of type 1 form may include day sleepiness, cataplexy, hypnagogic hallucinations, sleep paralysis, disturbed nocturnal sleep, and weight gain, especially in children.
2. The symptoms of type 2 form may include excessive daytime sleepiness, sleep paralysis, hallucinations, disturbed sleep, and automatic behaviors.

Diagnosis

1. Type 1 form can be diagnosed through physical examination, polysomnography findings, low hypocretin-1 levels in cerebral spinal fluid, and genetic counseling.
2. Type 2 form can be diagnosed through physical examination, polysomnogram, multiple sleep latency test, and cerebrospinal fluid test.

Treatment

1. Type 1 form can be treated by giving stimulants such as modafinil, methylphenidate, amphetamine, pitolisant, solriamfetol, anti cataplectic drugs (antidepressants), or sodium oxybate and good sleep hygiene.
2. Type 2 form can be treated through giving medications such as modafinil and lifestyle and proper sleep schedule.

The following table summarizes the difference between type 1 and type 2 narcolepsy.

Summary – Type 1 vs Type 2 Narcolepsy

Narcolepsy is a long-term sleep disorder of the brain and nervous system. It interferes with a person’s sleep-wake cycle. There are two main types of narcolepsy as type 1 and type 2. Type 1 narcolepsy causes cataplexy, while type 2 narcolepsy usually does not cause cataplexy. Furthermore, about 20% of narcolepsy cases are type 1 narcolepsy, whereas about 80% of narcolepsy cases are type 2 narcolepsy. This is the key difference between type 1 and type 2 narcolepsy.

FAQ: Type 1 and Type 2 Narcolepsy

1. Is narcolepsy a mental disease?

• Narcolepsy is a disabling neurodegenerative condition that is characterized by excessive daytime sleepiness (EDS), sleep fragmentation, sleep-related hallucinations, sleep paralysis, and cataplexy. It is categorized as a sleep disorder.

2. Can one wake a person with narcolepsy?

• It may be very difficult to wake someone with narcolepsy, but this does not present any health risks on its own. If there is a need to wake someone with narcolepsy for safety reasons, they may be confused and disoriented. Therefore, it should be done by an experienced healthcare practitioner.

3. What is the main cause of narcolepsy?

• Narcolepsy is thought to be caused by a lack of a brain chemical called hypocretin (also known as orexin), which usually regulates sleep. The deficiency is thought to be the result of the immune system mistakenly attacking parts of the brain that produce hypocretin. Hence, this condition is mostly autoimmune.

4. What are the symptoms of narcolepsy type 1?

• Symptoms of type 1 narcolepsy are EDS or sleep attacks, cataplexy (sudden and brief muscle weakness that’s triggered by strong emotions), sleep paralysis, hallucinations, insomnia, or difficulty falling or staying asleep at night.

5. How does it treat narcolepsy 2?

• Type 2 narcolepsy is treated with medications that promote alertness, control cataplexy, and reduce EDS. The most common narcolepsy medications include modafinil. Other treatments include lifestyle modifications and a proper sleep schedule.

Reference:

1.   “Narcolepsy: What It Is, Causes, Symptoms & Treatment.” Cleveland Clinic.
2.   Gillette, Hope. “Type 2 Narcolepsy: Symptoms, Diagnosis, and Treatment.” Healthline, Healthline Media.

Image Courtesy:

1. “Sleep Stage N3” By NascarEd – Own work (CC BY-SA 3.0) via Commons Wikimedia

Related posts:

What is the Difference Between Cyst and Abscess Difference Between Obstructive and Restrictive Lung Disease Difference Between Flu A and B How to Tell the Difference Between Groin Strain and Hernia What is the Difference Between Orthostatic Hypotension and Vasovagal Syncope