Which condition involves immune-mediated destruction of the myelin sheath?

The condition that involves immune-mediated destruction of the myelin sheath is multiple sclerosis. In this disorder, the immune system mistakenly attacks the central nervous system, specifically targeting the myelin, which is the protective covering that surrounds nerve fibers. This leads to inflammation and damage, disrupting the normal flow of electrical impulses along the nerves.

As a result, individuals with multiple sclerosis may experience a wide range of symptoms, including muscle weakness, coordination and balance issues, visual disturbances, and cognitive changes. The demyelination process makes it difficult for nerves to transmit signals effectively, which can lead to the progressive neurological impairments associated with the disease.

Other conditions listed do not primarily involve the immune system targeting the myelin sheath. For instance, narcolepsy is primarily a sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks, while ADHD and schizophrenia are neurodevelopmental and psychiatric disorders, respectively, that do not involve immune-mediated damage to myelin.