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| Author(s): |
Rebeca Maria Gonçalves
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas |
| Defense date: | 2019-01-29 |
| Examining board members: |
Ana Carolina Coan;
Fábio Rogério;
Luiz Eduardo Betting
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| Advisor: | Brunno Machado de Campos; Ana Carolina Coan |
| Abstract | |
Introduction: Epilepsies are diseases of functional and anatomically connected neural networks, which may be associated with the variability of ictal phenomena, interictal behavior and prognosis. To date, studies of changes in neural networks in patients with epilepsy have been based on the analysis of groups of individuals. Knowledge of individual patterns of functional and structural neural network changes may contribute to a better understanding of the factors involved in these diseases as well as may become useful markers for prognostic and treatment response assessment in patients with pharmacoresistant epilepsies. Objective: To investigate the distribution and possible overlap of individual functional and structural neural networks alterations in patients with pharmacoresistant focal epilepsies. Methods: We selected twenty-four patients (18-56 years) with focal pharmacoresistant epilepsies with hippocampal sclerosis (HE), focal cortical dysplasia (FCD) and gamglioglioma etiologies, who had been submitted to EEG concomitant with functional MRI acquired in a 3T scanner, with echo-planar sequence and T1-weighted images. Interictal epileptiform epileptiformes (IEDs) were visually identified in the EEG and used to define hemodynamic changes through the blood oxygen level-dependent (BOLD) (SPM12, p<0.001, minimum of 20 contiguous voxels). The assessment of individualized gray matter (GM) atrophy was performed with voxel-based morphometry, using an algorithm for the individual analysis (Statistical Parametric Mapping (SPM12, toolbox SSVBM), two-sample t-test, p<0.05, corrected with Family Wise Error (FWE). Images of 150 healthy subjects (19-69 years) were used as controls and compared to the image of each patient. We evaluated the co-localization of structural and functional abnormalities through the co-registration of maps of each patient. For all subjects, the epileptogenic zone (EZ) was defined according to extensive pre-surgical evaluation. Results: Individual structural abnormalities demonstrated GM atrophy ipsilateral to EZ in frontal, temporal and parietal lobes and in the contralateral frontal lobe. Regarding functional abnormalities, hemodynamic changes related to the IEDs was observed in frontal, temporal and parietal lobes ipsilateral to the ZE and in the contralateral frontal lobe. The duration of epilepsy has a moderate negative correlation with the number of regions with hemodynamic related changes to IEDs (r = -0.358 / p = 0.043). Co-registration of individual maps demonstrated that 45,8% (11/24) of the patients had overlapping functional and structural abnormalities; however, on average, only 1.26% of the individual areas of structural abnormalities had an overlap with functional abnormalities. Conclusion: The present study did not demonstrate a significant overlap of GM atrophy and hemodynamic changes related to the IEDs in patients with focal pharmacoresistant epilepsies. These patients present an extensive network of functional and structural abnormalities that appear at regions distant from the EZ, more frequent in the hemisphere ipsilateral to the EZ. The overlapping findings through of individual analysis reported in these study, promote the verification of tools that can measure the overlap between specific areas in neuroimaging tests and to contribute for the prognosis of patients with focal epilepsies (AU) | |
| FAPESP's process: | 16/10812-0 - Evaluation of individual patterns of functional and structural neural networks in patients with focal epilepsy |
| Grantee: | Rebeca Maria Gonçalves |
| Support Opportunities: | Scholarships in Brazil - Master |