AUTHOR=Guimarães Rachel Paes , Arci Santos Maria Cristina , Dagher Alain , Campos Lidiane Soares , Azevedo Paula , Piovesana Luiza Gonzaga , De Campos Brunno Machado , Larcher Kevin , Zeighami Yashar , Scarparo Amato-Filho Augusto C. , Cendes Fernando , D’Abreu Anelyssa Cysne Frota 

TITLE=Pattern of Reduced Functional Connectivity and Structural Abnormalities in Parkinson’s Disease: An Exploratory Study

JOURNAL=Frontiers in Neurology

VOLUME=Volume 7 - 2016

YEAR=2017

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2016.00243

DOI=10.3389/fneur.2016.00243

ISSN=1664-2295

ABSTRACT=Background: Parkinson’s disease (PD) is progressive and affects different brain areas.
Objectives: We aimed to describe structural and functional changes in different PD clinical stages.
Methods: Sixty-six patients with PD (57.94±10.25 years) diagnosed according to the UK Brain Bank criteria were included. We performed a whole brain analysis using voxel-based morphometry (VBM-SPM 8 software), cortical thickness (CT) using CIVET and resting state-fMRI using the NIAK software to compare patients and controls. For VBM and CT we classified subjects into three groups according to disease severity: mild PD (HY 1-1.5), moderate PD (HY 2-2.5) and severe PD (HY 3-5).
Results: We observed GM atrophy in the insula and inferior frontal gyrus in the moderate PD and the moderate and in the insula, frontal gyrus, putamen, cingulate and paracingulate gyri in the severe groups. In the cortical thickness analysis, in mild PD cortical thinning was restricted to the superior temporal gyrus, gyrus rectus and olfactory cortex; in the moderate group the postcentral gyrus, supplementary motor area and inferior frontal gyrus were also affected; in the severe PD areas such as the precentral and postentral gyrus, temporal pole, fusiform and occipital gyrus had reduced cortical thinning. We observed altered connectivity at the default mode, visual, sensorimotor and cerebellar networks.
Conclusions: Subjects with mild symptoms already have cortical involvement, however further cerebral involvement seems to follow Braak’s proposed mechanism. Similar regions are affected both structurally and functionally. We believe the combination of different MRI techniques may be useful in evaluating progressive brain involvement and they may eventually be used as surrogate markers of disease progression.