Striatal hand in Parkinson’s disease: the re-evaluation of an old clinical sign

Among postural abnormalities in Parkinson’s disease (PD), striatal hand (SH) is a particularly underexplored phenomenon. It leads to extreme abnormalities of hand posture, causing altered dexterity, pain and disfigurement. In our study, three blinded investigators examined several pictures of the hands of individuals with PD (N = 40) and controls (N = 15). The investigators quantified postural alterations using the Striatal Hand Score. Demographic and clinical data were also collected. As no differences were detected among investigators agreement, a final Hand Score (HS, range 0–4) was obtained for each hand. The Striatal Hand Score in both the left and right hand was significantly different in PD compared to controls (p < 0.001 for both left and right hand). Striatal hand was significantly worse on the side of PD onset, and on the side with greater PD symptomatology. The finding of a striatal hand was 100 % specific for a diagnosis of PD. Nine PD subjects were evaluated both on and off medication, and dopaminergic treatment did not significantly change the Striatal Hand Score. Our findings suggest that in patients without any explanation for hand deformities other than PD, striatal hand occurs very often, and is highly specific for the side of worst PD involvement. We recommend including an evaluation for SH as part of routine practice. This study emphasizes the importance of a careful observation of the patient in order to improve diagnostic accuracy.