Associations between neuropsychiatric symptoms and cognition in Chinese idiopathic Parkinson's disease patients

The associations between neuropsychiatric symptoms and cognition, frontal lobe function and frontal behavioral changes in the Chinese idiopathic Parkinson's disease (PD) population are largely unknown. This study included 348 idiopathic PD patients from southwest China. Neuropsychiatric symptoms were investigated using the Neuropsychiatric Inventory Questionnaire (NPI), and cognition was assessed using Addenbrooke's Cognitive Examination-Revised (ACE-R). The Frontal Assessment Battery (FAB) was used to evaluate frontal function and the Frontal Behavior Inventory (FBI) was used to assess frontal behavioral changes. The mean (± standard deviation) age of the PD patients was 60.24 ± 12.07 years, and the mean disease duration was 3.88 ± 3.34 years. The mean NPI score was 3.49 ± 4.00. The mean score of ACE-R was 76.82 ± 16.73. The mean score of FAB was 15.27 ± 2.90, and the mean score of FBI was 3.18 ± 5.17. Weak negative correlations between the NPI and ACE-R scores as well as FAB score were found in the total sample, the male patient subgroup, the early onset PD subgroup and the late onset PD subgroup. Strong positive correlations were found between the NPI and FBI scores in the total sample (r=0.661, p<0.001), the male patient subgroup (r=0.789, p<0.001) and the late onset PD subgroup (r=0.749, p<0.001). Moderate positive correlations were found between the NPI and FBI scores in the female patient subgroup (r=0.536, p<0.001) and the early onset PD subgroup (r=0.462, p<0.001). Neuropsychiatric symptoms were closely associated with frontal behavioral changes but were not closely related with worse cognition and frontal lobe function in the Chinese idiopathic PD population.