A neurophysiological profile in Parkinson's disease with mild cognitive impairment and dementia in China.

Mild cognitive impairment (MCI) and dementia (D) are frequent features of Parkinson's disease (PD) but widely disparate criteria have been used. Our understanding of the prevalence and cognitive profile of Chinese PD patients remains limited. In order to determine the frequency and pattern of cognitive dysfunction and identify risk factors for cognitive dysfunction in the Chinese Han PD population we performed a cross-sectional study in a cohort of 330 PD patients and 163 healthy controls. Five cognitive domains (executive function, attention, praxis and visuospatial function, memory, and language) and mood/behavior were evaluated. According to the Movement Disorder Society Task Force consensus criteria, up to 29.1% of PD patients were classified as PD-MCI and 32.1% as PD-D. Impairments occur in a range of cognitive domains with dysexecutive profile predominating. Healthy controls also outperformed cognitively preserved PD patients in tasks of executive function and attention. Logistic regression indicated that PD-MCI may be predicted by lower educational level and apathy. Additionally, later disease onset, longer disease duration, more severe motor symptoms and higher neuropsychiatric inventory score were associated with a faster transition from PD-MCI to PD-D. These findings suggest that all PD patients should undergo routine cognitive screening. For high-risk patients early recognition and therapeutic intervention is imperative.