Preditores de declínio cognitivo na doença de Parkinson

Abstract

Cognitive impairment in Parkinson's disease, whether in the form of mild cognitive impairment or dementia, results in significant morbidity and mortality, being early diagnosis essential. Identification of patients at risk to develop cognitive impairments may be based on clinical data or exams. The ideal biomarker would be one that provides correlation between clinic- anatomic data by noninvasive method, increasing the diagnostic accuracy. In this sense, magnetic resonance imaging with automatic segmentation (FreeSurfer) measure volume and thickness being a useful tool as it has histological validation. Objective: To evaluate clinical, neuropsychological and neuroimaging (volume and thickness) variables that could be related to worse cognitive outcome over 18 months in Parkinson`s disease compared with controls. Method: Parkinson`s disease patients were recruited according to established inclusion and exclusion criteria as well individuals without any neurological or psychiatric diagnosis (controls). All were submitted to the same protocol: neurological, neuropsychological and neuroimaging evaluation. After 18 months, they were reassessed by neurological and neuropsychological evaluation. Results: Parkinson's disease group presented worse performance in neuropsychological evaluation in both initial and final evaluations. The results obtained by FreeSurfer revealed a statistically significant reduction in the volume and thickness of numerous cortical and subcortical structures in the Parkinson's disease group comparing with the control group. Worse cognitive outcome was more prevalent in the Parkinson's disease group. Conclusions: Individuals with Parkinson's disease present a higher prevalence of cognitive impairment with worse evolution over 18 months. The predictors of worse cognitive outcome were rigid-akinetic form, worse performance in initial neuropsychological assessment and lower subcortical volumes.