Association between cognitive performance and manual dexterity in patients with Parkinson's disease

Parkinson's disease (PD) is a progressive neurological condition resulting from the degeneration of dopaminergic neurons in the substantia nigra. Impaired manual dexterity and cognitive impairment are common symptoms and are often associated with recurrent adverse events in this population.

To verify the association between cognitive performance and manual dexterity in people with PD.

This is a cross-sectional observational study, with 29 participants, who underwent cognitive and manual dexterity assessments, and the following tools were used: Trail Making Test, box and block test (BBT), Learning Test of Rey and Nine Hole Peg Test. Descriptive statistics for clinical and demographic data were performed using mean and standard deviation, and data normality was assessed using the Shapiro-Wilk test. Spearman's nonparametric test was used to determine the correlation between variables.

Our findings revealed significant associations between cognitive performance and manual dexterity. The nine-hole peg test positively correlated with TMT-Part A and Part B, establishing a relationship between manual dexterity and cognitive functions such as attention and mental flexibility. On the other hand, BBT showed an inverse relationship with TMT-Part B, indicating that longer time on this task was associated with lower manual dexterity.

Fine manual dexterity had a significant correlation with visual search skills and motor speed, while gross motor dexterity had a negative correlation with cognitive skills. No significant results were demonstrated regarding the interaction between manual dexterity and memory.