Hand Fine Motor Skill Disability Correlates with Cognition in Patients with Moderate-to-Advanced Parkinson's Disease

In older individuals, hand fine motor skill disability is associated with cognitive levels. Similarly, patients with moderate-to-advanced Parkinson's disease (PD) often have cognitive dysfunction. Here, we investigated the association between hand fine motor skill and cognitive dysfunction in patients with moderate-to-advanced PD. Moderate and advanced PD patients with and without dementia were identified from the Taiwan Data Bank of Persons with Disability. Hand fine motor capacities, namely pen holding, buttoning, and knotting, were assessed with the World Health Organization Disability Assessment Schedule 2.0. Statistical analyses were performed on Statistical Analysis System (SAS) and a p value of <0.05 was considered significant. In total, 3440 patients with PD were enrolled, of which 612 had dementia, exhibiting significant disability in all three tasks. After adjustments for age, sex, and PD severity, pen holding and knotting were significantly associated with PD dementia. The presence of any disability in either task was not only sensitive to the presence of dementia but also associated with cognitive disability in moderate and advanced PD patients without dementia. In conclusion, hand fine motor skill disability was associated with cognitive disability in patients with moderate-to-advanced PD. These simple hand fine motor skills may thus be applicable in screening tests for the early identification of cognitive dysfunction in patients with moderate-to-advanced PD.