Functional neurologic disorder (FND) refers to a neurological condition caused by changes in how brain networks work, rather than changes in the structure of the brain itself, as seen in many other neurological disorders. Physical symptoms of FND are genuine but cannot be explained by changes in the brain structure. The exact cause of FND is unknown.

FND symptoms may include:

• Seizure-like episodes
• Movement problems
• Problems with cognitive function
• Dizziness
• Speech difficulties, such as sudden onset of stuttering or trouble speaking
• Problems with vision or hearing
• Pain (including chronic migraine)
• Extreme slowness and fatigue
• Numbness or inability to sense touch

FND can cause multiple symptoms that significantly interfere with how a person functions and copes with daily life. Symptoms of FND are not intentionally produced and can involve any part of the body. Symptoms may appear suddenly, increase with attention to them, and decrease when the person is distracted.