Involuntary, slow, continually changing twisting movements usually affecting the face, neck, and distal limbs, with sequence athetosis → choreoathetosis → chorea → hemiballismus, is best described as which movement abnormality?

• A. Athetosis
• B. Chorea
• C. Dystonia
• D. Myoclonus

Answer: (A)

This description centers on slow, continuous, twisting movements that change shape over time. Athetosis is defined by those exact qualities—writhing, irregular motions that affect the face, neck, and limbs, especially the distal parts. The sequence from athetosis toward chorea and other hyperkinetic movements reflects a spectrum of movement disorders, but the hallmark descriptor here is the slow, flowing, twisting quality of athetosis. Chorea would be faster, more abrupt and irregular; dystonia involves sustained postures from muscle contractions; myoclonus is characterized by brief, shock-like jerks. So the movement abnormality described is athetosis.