Which movement disorder is described as involuntary movements in young kids with slowly progressive course and diurnal fluctuations and is treated with low-dose levodopa?

• A. Athetosis
• B. Chorea
• C. Choreoathetosis
• D. Dopamine-responsive dystonia

Answer: (D)

Dopamine-responsive dystonia (Segawa disease) is being described. It typically starts in childhood with dystonic, involuntary movements that are slowly progressive and show marked diurnal fluctuation—often better after waking and worsening as the day progresses. A hallmark is a dramatic improvement with low-dose levodopa, reflecting a dopamine synthesis deficiency in the brain. This combination of early onset, diurnal pattern, and strong levodopa responsiveness is what sets it apart from other movement disorders.

The other patterns—slow, writhing athetoid movements; rapid, irregular choreiform movements; or a mix of chorea with dystonia—do not characteristically display the daytime fluctuation and the pronounced, easy response to small doses of levodopa that define dopamine-responsive dystonia.