Structural and functional analyzes in Parkinson's disease

Author(s)

Rachel Paes Guimarães

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2015-10-23

Examining board members

Fernando Cendes; Tânia Aparecida Marchiori de Oliveira Cardoso; Luis Eduardo Gomes Garcia Betting; Henrique Ballalai Ferraz; Marcondes Cavalcante Franca Junior

• Advisor: Fernando Cendes; Anelyssa Cysne Frota D'Abreu

Abstract

Introduction: Parkinson's disease (PD) is the second most common neurodegenerative disease in the world. It is a multisystemic disorder characterized by motor and non-motor symptoms. The pathophysiology of PD has not been fully elucidated and previous imaging studies mostly used voxel-based morphometry, comparing subgroups of patients, with or without certain symptoms. Objectives: The aim of this study was to evaluate individuals with PD through different imaging techniques. Methods: We evaluated 101 patients (71 men) and 69 controls. Eighty-five patients underwent clinical evaluation and of those, 36 had the first symptom at right, and in 56 the main symptom was tremor. Patients were assessed through scales: Unified Parkinson's Disease Rating Scale (UPDRS) (59.33 ± 9.8), Hoehn & Yahr (H & Y) (2.84 ± 1.2), Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA-COG) (19:24 ± 6.8), Scales for Outcomes in Parkinson's Disease - Psychiatric Complications (SCOPA-PC) (3.6 ± 7.8), Non-Motor Symptoms Scale (NMSS) (69.57 ± 48.19) and Schwab & England scale for activities of daily living (73% ± 22%). We use the following image analysis techniques: diffusion tensor imaging (DTI), cortical thickness analysis (CTA) and resting state functional magnetic resonance imaging (rs-fMRI). Results: In the DTI, we evaluated three tracts: corticospinal, cingulum and corpus callosum. In the corticospinal tract, we found increased fractional anisotropy (FA) and decreased mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). There were no significant differences in the cingulum, and we observed decreased FA in the corpus callosum. There was an association between MD and RD in the corticospinal tract and cingulum with the SCOPA-COG scores, and between the FA and RD in the corpus callosum and the UPDRS-III. FA values ??lower than 0.559467 in the corticospinal tract, properly differentiated patients from controls in 85.04 % of cases, with a sensitivity of 89.04% and sensitivity of 79.63%. There were no significant differences between patients and controls in CTA, however, when the patients were divided into mild, moderate and severe subgroups, we found differences in the three groups. The mild group had decreased CT in the superior temporal gyrus, gyrus rectus and the olfactory cortex, the moderate group exhibited reduced CT in the postcentral gyrus, the supplementary motor area and the inferior frontal gyrus, while the severe group presented decreased CT in the inferior frontal gyrus, precentral and postcentral gyrus, supplementary motor area, inferior frontal gyrus, gyrus rectus, temporal pole, fusiform gyrus, middle temporal gyrus and occipital gyrus. We found an association between the UPDRS-III scores and CT. We found decreased connectivity between various areas in the frontal, temporal and occipital lobes, thalamus and brainstem. We found reduced connectivity in the default mode network and the visual network. Conclusion: We used three complementary techniques to assess brain changes in PD. We demonstrated structural and functional changes in similar regions; however, it is still not possible to determine whether the functional deficits occur due to structural changes or vice versa. FA values ??in the corticospinal tract may be used as a biomarker; however, longitudinal studies are necessary to confirm these findings (AU)

• FAPESP's process: 11/19958-4 - Structural and functional conectivity analysis in Parkinsons Disease Patients
• Grantee: Rachel Paes Guimarães
• Support Opportunities: Scholarships in Brazil - Doctorate