Narcolepsy : Overview

Narcolepsy is a neurological disorder characterized by its impact on the sleep-wake cycle, most notably causing rapid onset rapid eye movement (REM) sleep. This disorder is hallmarked by excessive daytime sleepiness (EDS), which manifests as an overwhelming tendency to fall asleep during daytime activities. Patients often experience uncontrollable sleep attacks, where they fall asleep suddenly and without warning. Additionally, sleep fragmentation is common, leading to disrupted and unrefreshing sleep.

A key feature of narcolepsy is its association with several distinct symptoms:

• Cataplexy: This is a sudden, temporary loss of muscle tone often triggered by strong emotions such as laughter or anger. It is predominant in narcolepsy type 1 (formerly known as narcolepsy with cataplexy).
• Sleep Paralysis: This involves a temporary inability to move or speak while falling asleep or upon waking.
• Hypnagogic Hallucinations: Vivid, dream-like experiences that occur while falling asleep.

Narcolepsy is categorized into two types:

1. Narcolepsy Type 1: This form includes cataplexy and is more closely associated with a deficiency in the brain hormone hypocretin (orexin).
2. Narcolepsy Type 2: Formerly known as narcolepsy without cataplexy, this type lacks the cataplexy component.

Diagnosis of narcolepsy is often delayed, with a common lag of 5-10 years from the onset of...