Fonzarelli Syndrome

A 77-year-old man presented with a 1-year history of upper limb rest tremor, rigidity, and bradykinesia. He reported focal dystonia affecting the right thumb over the preceding 7 years, resulting in a constant "thumbs up" gesture reminiscent of the fictional television character Arthur Fonzarelli. Subsequent levodopa therapy reduced his bradykinesia and rigidity, but did not ameliorate the dystonia.

While foot dystonia is a common feature in late Parkinson disease (PD), dystonia may precede the development of PD by several years. Writer's cramp has been described as an early manifestation, with extension of the great toe also noted (the striatal foot).