Narcolepsy

Narcolepsy is a chronic neurological disorder that disrupts the brain’s ability to regulate sleep-wake cycles. It is characterized by excessive daytime sleepiness and sudden sleep attacks.

The condition is divided into two types:

• Narcolepsy Type 1 (NT1) – Associated with cataplexy (sudden loss of muscle tone).
• Narcolepsy Type 2 (NT2) – Does not include cataplexy.

In normal sleep cycles, the brain transitions from non-rapid eye movement (NREM) sleep to rapid eye movement (REM) sleep gradually. However, individuals with narcolepsy bypass NREM and enter REM sleep almost immediately. This disruption occurs both at night and during the day, causing REM-related symptoms such as vivid dreams, sleep paralysis, and hallucinations while awake.

Growing evidence suggests that narcolepsy, particularly NT1, is an autoimmune disease.

Research indicates that the body’s immune system mistakenly attacks hypocretin-producing neurons in the brain, leading to a deficiency of hypocretin (orexin), a key neurotransmitter that regulates wakefulness and REM sleep.

Symptoms of narcolepsy vary in severity but often include:

• Excessive daytime sleepiness (EDS) – Persistent drowsiness and sudden sleep episodes.
• Cataplexy (NT1 only) – Sudden muscle weakness triggered by emotions.
• Sleep paralysis – Temporary inability to move or speak when falling asleep or waking up.
• Disrupted nighttime sleep – Frequent awakenings and poor sleep quality.
• Hallucinations – Vivid dream-like experiences while awake or falling asleep.
• Automatic behavior – Performing routine tasks without awareness or memory.

Narcolepsy is frequently associated with other medical conditions, including:

• Sleep disorders: Obstructive sleep apnea, insomnia, restless leg syndrome.
• Neurological & psychiatric conditions: Migraines, schizophrenia, ADHD, anxiety, depression.
• Metabolic & autoimmune conditions: Diabetes, obesity, fibromyalgia, chronic pain, arthritis.

The onset of narcolepsy is most common between ages 10 and 20, but it can develop at any age.

Key risk factors include:

• Genetic predisposition – Those with a family history are 20-40 times more likely to develop narcolepsy.  The HLA-DQB1*06:02 gene, which is linked to autoimmune diseases, increases susceptibility.
• Low hypocretin levels – Most NT1 patients have a severe deficiency of this wake-promoting neurotransmitter.
• Infections & immune triggers – Studies suggest that H1N1 influenza and certain vaccines may trigger narcolepsy in genetically susceptible individuals, though more research is needed.
• Environmental Triggers: Infections (such as H1N1 flu) and certain vaccines (like the Pandemrix H1N1 vaccine in Europe) have been associated with NT1 onset, suggesting an immune-triggered response.

• Developing New Narcolepsy Treatments (2022)
• Narcolepsy (2022)
• European guideline and expert statements on the Management of narcolepsy in adults and children (2021)
• Cardiovascular disorders in narcolepsy: Review of associations and determinants (2021)
• Recently approved and upcoming treatments for narcolepsy (2020)