Dystonia is defined as which of the following?

• A. State of abnormal muscle tone, resulting in spasm or abnormal posture. Typically caused by neuro-disease or drug side-effects.
• B. Temporary loss of memory.
• C. Rapid, involuntary movements that worsen with voluntary action.
• D. Inflammation of joints.

Answer: (A)

Dystonia is a movement disorder defined by sustained or repetitive muscle contractions that produce twisting, abnormal postures or movements. The description of a state of abnormal muscle tone with spasms or abnormal posture, often due to a neurological condition or drug side effects, matches this definition precisely. Dystonia can be focal or generalized and may be drug-induced from medications that affect dopamine signaling or arise from underlying neuro disease impacting basal ganglia circuits. The other options describe conditions that are not dystonia: temporary memory loss is amnesia, rapid involuntary movements that worsen with voluntary action suggest chorea, and inflammation of joints denotes arthritis.