What is cataplexy?

From the Guidelines

Cataplexy is a sudden, temporary loss of muscle control triggered by strong emotions, most commonly laughter, surprise, or anger, and is almost exclusively associated with narcolepsy type 1, a sleep disorder characterized by excessive daytime sleepiness.

Definition and Characteristics

Cataplexy is a condition that affects individuals with narcolepsy, causing them to experience sudden and temporary loss of muscle control, often triggered by strong emotions such as laughter, surprise, or anger. During a cataplectic episode, a person remains fully conscious but may experience partial or complete muscle weakness, ranging from slurred speech to complete collapse. Episodes typically last from a few seconds to several minutes.

Treatment Options

Treatment for cataplexy primarily involves medications such as:

• Sodium oxybate (Xyrem) at doses of 2.25-4.5g taken twice nightly, as recommended by the American Academy of Sleep Medicine 1
• Antidepressants like venlafaxine (37.5-225mg daily) or fluoxetine (20-60mg daily)
• Pitolisant (Wakix, 8.9-35.6mg daily) These medications work by either promoting consolidated nighttime sleep or affecting neurotransmitters that regulate muscle tone.

Lifestyle Modifications

Lifestyle modifications, such as maintaining regular sleep schedules and avoiding emotional triggers, can also help manage symptoms of cataplexy.

Pathophysiology

Cataplexy occurs because narcolepsy disrupts the brain's ability to regulate the transition between sleep and wakefulness, allowing REM sleep-related muscle paralysis to intrude into waking consciousness during emotional arousal, as described in a study published in the Journal of Clinical Sleep Medicine in 2022 1.

Key Points

• Cataplexy is a sudden, temporary loss of muscle control triggered by strong emotions
• It is almost exclusively associated with narcolepsy type 1, a sleep disorder characterized by excessive daytime sleepiness
• Treatment involves medications such as sodium oxybate, antidepressants, and pitolisant, as well as lifestyle modifications
• Cataplexy occurs due to the disruption of the brain's ability to regulate the transition between sleep and wakefulness.

From the Research

Definition of Cataplexy

• Cataplexy is a symptom of narcolepsy, characterized by a sudden bilateral loss of voluntary muscular tone triggered by strong positive emotional factors 2.
• It is one of the major symptoms of narcolepsy, along with excessive daytime sleepiness (EDS) 3, 4, 5, 6.
• Cataplexy is caused by the early loss of hypothalamic hypocretin neurons, which regulate the sleep-wake cycle 2.

Characteristics of Cataplexy

• Cataplexy can be triggered by strong emotions such as laughter, excitement, or surprise 2.
• It is characterized by a sudden loss of muscle tone, which can range from mild to severe 2.
• Cataplexy can occur in up to 60% of patients with narcolepsy 6.

Treatment of Cataplexy

• The first-line treatment for cataplexy is sodium oxybate, which has been shown to be effective in reducing the frequency and severity of cataplexy attacks 5, 2.
• Antidepressants with norepinephrine/serotonin reuptake inhibitor properties, such as venlafaxine, can also be used to treat cataplexy 2.
• Other medications, such as pitolisant and solriamfetol, have been approved for the treatment of excessive daytime sleepiness associated with narcolepsy, and may also have anticataplectic effects 6.