Which motor symptom is most characteristic of Huntington's disease?

• A. Tremor
• B. Chorea
• C. Rigidity
• D. Bradykinesia

Answer: (B)

Huntington's disease is best thought of as a hyperkinetic movement disorder, where the defining motor feature is chorea—involuntary, irregular, flowing, dance-like movements that seem to shift from one muscle group to another. This occurs because degeneration of the striatal neurons (particularly in the indirect pathway) disrupts the normal inhibition of the thalamus, leading to excessive, involuntary movements throughout the body.

Tremor, rigidity, and bradykinesia are more characteristic of other conditions, especially Parkinson disease. Tremor is common in Parkinsonian and essential tremor disorders; rigidity and slowness (bradykinesia) are classic Parkinson features and can appear later in Huntington’s as the disease progresses, but they are not the hallmark motor symptom. So chorea stands out as the most characteristic motor sign in Huntington's disease.