Neuropsychological profile in patients with early stage of Parkinson's disease in Taiwan.

Given the importance of early detection and intervention for disease management, determining the vulnerable neuropsychological function in patients with early-stage Parkinson's disease (PD) is a priority. Here, we describe the neuropsychological pattern in early-stage PD patients with mild cognitive impairment (PD-MCI) and dementia (PDD) in Taiwanese population. The neuropsychological performance of 94 patients with PD was compared with that of 84 healthy controls (HCs) and available normative data, using a comprehensive neuropsychological assessment including tests of executive, memory, psychomotor speed, attention, visuospatial, and language functions. Our results showed that PD patients performed significantly worse on executive function (i.e., category of card sorting) and psychomotor speed (i.e., processing speed index). Up to 46.8% were classified as PD-MCI and the majority of those having single-domain impairment (68.2%); 9.6% met the consensus diagnostic criteria for PDD. Accordingly, we suggest that early-stage PD patients have cognitive dysfunction predominately in the anterior brain. Further follow-up study to determine how many percent of PD-MCI develop PDD is important. The effect of neurocognitive rehabilitation on executive function is also valuable in the subsequence study.