Asymmetric hand deformities with limited mobility

A 52-year-old woman presented to the rheumatology department with a 6-year history of progressively limited hand mobility, bilateral joint pain, and worsening hand deformities. Examination revealed asymmetric deformities of both hands, more pronounced on the left (Fig, A), without joint tenderness, swelling, or Heberden's and Bouchard's nodes. Laboratory tests, including C-reactive protein, rheumatoid factor, anticyclic citrullinated peptide antibody, antinuclear antibody, antidouble-stranded DNA antibody, and anti-Smith antibody, revealed no abnormalities. Hand X-rays showed no evidence of inflammatory arthritis. Treatment with nonsteroidal anti-inflammatory drugs and corticosteroids was ineffective. She was referred to the neurology clinic, where neurological examination revealed bradykinesia and increased muscle tone in all 4 limbs, especially the left upper limb, without tremor or postural instability. Brain and cervical spine magnetic resonance imaging were unremarkable. Fluorine-18-L-dihydroxyphenylalanine (¹⁸F-DOPA) positron emission tomography/computed tomography showed decreased dopamine metabolism in the bilateral striatum, which was more pronounced on the right (Fig, B). A diagnosis of striatal hand deformities (SHD) was made, and her symptoms improved with levodopa.