Clinical correlations of striatal hand deformities in Parkinson's disease

Hand deformities have been recognized since the 19th century as part of the postural abnormalities observed in Parkinson's disease (PD). However, their pathogenesis and clinical correlations are poorly understood.

We evaluated 104 hands of 52 consecutive patients with PD by high-resolution photographs taken from the radial aspect of each hand; the degree of flexion of the 2nd metacarpophalangeal (MCP) joint was measured by software. The presence of classical striatal hand deformity (CSHD) was also evaluated, defined as MCP flexion, proximal interphalangeal joint extension, and distal interphalangeal joint flexion.

Patients with PD had a mean age of 63.3 ± 12.7 years, and 29 (56%) were male. The degree of MCP joint flexion in both hands showed moderate correlation with the MDS-UPDRS-III motor score (r = 0.518, P < 0.001), mainly related to ipsilateral rigidity and ipsilateral bradykinesia scores, and fair correlation with the Hoehn-Yahr stage. A CSHD only correlated with a younger age at onset of PD (P = 0.049). These hand deformities were not markers of dyskinesia, levodopa equivalent dose, or cognitive dysfunction.

Metacarpophalangeal joint flexion is the most common hand deformity in PD and correlates with rigidity and bradykinesia. A CSHD was only related to a younger age at onset.