Volumetric brain analysis as a predictor of a worse cognitive outcome in Parkinson's disease.

Cognitive impairment in Parkinson's disease (PD) results in significant morbidity and mortality being early diagnosis essential. Identification of patients who are at higher risk of developing cognitive impairment based only on clinical data is not sufficient. To this end, magnetic resonance imaging (MRI) with automatic segmentation, such as FreeSurfer, could be a useful tool with high accuracy because it has histological validation. OBJECTIVES: The objective of this study was to evaluate clinical, neuropsychological and FreeSurfer variables that may be related to worse cognitive outcomes over 18 months in PD patients compared with controls. METHODS: PD patients were recruited according to established inclusion and exclusion criteria as well individuals without any neurological or psychiatric diagnosis and were submitted to the same protocol: neurological, neuropsychological and neuroimaging evaluations. After 18 months, the study subjects were reassessed by neurological and neuropsychological evaluations. RESULTS: Of 171 individuals selected for first evaluation, 96 concluded the study during 18-month follow-up. The PD group presented worse performance in the neuropsychological assessment during both the initial and final evaluations. The results obtained by FreeSurfer revealed a significant reduction (unilateral or bilateral) in the volume of thalamus, caudate nucleus, putamen, hippocampus, amygdala, accumbens, corpus callosum and cerebral gray matter in the PD group. A worse cognitive outcome was more prevalent in the PD group. CONCLUSIONS: Worse cognitive performance documented by neuropsychological assessment in the PD group was correlated with reduced volume of several structures by FreeSurfer analysis and may be a biomarker of cognitive decline.

Correlation of MRI Visual Scales with Neuropsychological Profile in Mild Cognitive Impairment of Parkinson's Disease.

Few studies have evaluated magnetic resonance imaging (MRI) visual scales in Parkinson's disease-Mild Cognitive Impairment (PD-MCI). We selected 79 PD patients and 92 controls (CO) to perform neurologic and neuropsychological evaluation. Brain MRI was performed to evaluate the following scales: Global Cortical Atrophy (GCA), Fazekas, and medial temporal atrophy (MTA). The analysis revealed that both PD groups (amnestic and nonamnestic) showed worse performance on several tests when compared to CO. Memory, executive function, and attention impairment were more severe in amnestic PD-MCI group. Overall analysis of frequency of MRI visual scales by MCI subtype did not reveal any statistically significant result. Statistically significant inverse correlation was observed between GCA scale and Mini-Mental Status Examination (MMSE), Montreal Cognitive Assessment (MoCA), semantic verbal fluency, Stroop test, figure memory test, trail making test (TMT) B, and Rey Auditory Verbal Learning Test (RAVLT). The MTA scale correlated with Stroop test and Fazekas scale with figure memory test, digit span, and Stroop test according to the subgroup evaluated. Visual scales by MRI in MCI should be evaluated by cognitive domain and might be more useful in more severely impaired MCI or dementia patients.