Ballism

Part of speech: noun

Definitions

1. A neurological movement disorder characterized by involuntary, irregular, large-amplitude flinging movements of the limbs caused by damage to the subthalamic nucleus or related brain regions
2. A rare condition involving sudden, uncontrollable, and violent jerking motions in the arms and legs resulting from abnormalities in specific parts of the brain responsible for motor control
3. A syndrome marked by rapid, forceful, and erratic limb movements due to lesions or dysfunction in brain structures that regulate voluntary motion, typically the subthalamic area

Etymology: Ancient Greek "ballizein" meant to prance or jump about, a verb for restless, leaping movement. Its root, "ballein," meant "to throw," which also gave Greek "ballista," the siege engine that hurled stones, and English "ballistic." The shared root fits the disorder's flailing limbs, which look as if they are being thrown about. English took the medical term from the Greek noun "ballismos," probably through Latin "ballismus," for the violent, involuntary flinging of an arm or leg. It most often appears as "hemiballismus," where the flinging affects one side of the body, and it is usually linked to damage to a deep brain structure called the subthalamic nucleus.

Synonyms: chorea, hemiballismus, movement disorder, motor disorder

Antonyms: stillness, immobility