Early Impairment of Chopsticks Skills in Parkinsonism Suggests Progressive Supranuclear Palsy

BACKGROUND AND PURPOSE: Chopsticks are a primary eating utensil in East Asia, but systematic assessments of chopsticks skills in parkinsonian disorders is lacking. We aimed to identify any differences in chopsticks skills in the early stages of Parkinson's disease (PD) and atypical parkinsonism (AP), including progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal syndrome (CBS). METHODS: We consecutively recruited 111 patients with PD and 74 with AP (40 with PSP, 30 with MSA, and 4 with CBS) who were in a drug-naïve state. The motor and cognitive functions of the patients were evaluated using a standardized protocol. Everyday chopsticks skills were evaluated using a chopsticks questionnaire developed in-house. The chopsticks skills test (CST) involved counting the number of pills that the subject was able to carry using chopsticks between two dishes separated by 20 cm within 20 seconds. RESULTS: Patient responses to the questionnaire indicating poor chopsticks skills (“I cannot pick up some of the food items” or “I cannot use chopsticks anymore”) were present in 23.0% of AP patients and 30% of PSP patients, compared to only 5.6% of PD patients [odd ratio (OR)=5.07 and OR=7.29, p≤0.001 in both]. The performance in the CST was worse in PSP than in PD (p<0.001). The CST results were correlated with hand motor skills including in the coinrotation test, timed figure-tapping test, and motor Unified Parkinson's Disease Rating Scale scores in all of the patient groups (p<0.001). In PSP, a decline in visuospatial function and frontal executive function was associated with a poor performance in the CST in addition to poor motor performance (p<0.05). CONCLUSIONS: Impairments in chopsticks skills were more common in PSP than in PD during the early stages of parkinsonism. This suggests that early functional impairment of chopsticks skills can be used as a warning sign for PSP.