Funcionamento executivo no traumatismo cranioencefálico : estudos neuropsicológicos de desempenho e de neuroimagem estrutural

Abstract

TBI individuals may present great functional disability. Most of these dysfunctions is related to clinical manifestations of cognitive impairment, which creates several losses in different areas, such as work, autonomy and, as a consequence, on the quality of life of individuals and their relatives. In this context, studies have discussed the heterogeneity of clinical manifestations in TBI, which challenges research of clinical trials and characterization studies as a whole. One of the main issues in the field of clinical and cognitive neuropsychology is the understanding of executive functions (EF) post-TBI and their neural correlates. For this reason, it is of great interest to integrate neuropsychological evaluation, classical methods of clinical neuropsychology and neuroimaging. This dissertation aimed to investigate EF in TBI individuals by means of two studies. The first study investigated the profile of executive functioning in a sample of TBI individuals. This study included an extensive neuropsychological evaluation with a primary focus in FE. Results showed three different profiles of FE: Cluster 1 was characterized by difficulties in processing speed, phonemic verbal fluency and inhibition; Cluster 2 was formed by multiple deficits in FE, such as processing speed, working memory, planning, cognitive flexibility and verbal fluency; finally Cluster 3 had no or very mild difficulties on the EF examined. The second study investigated the two cases of adults with mild TBI with different education levels on EF performance and brain structures volumetry and cortical thickness. The patient with high education surpassed the patient with low education in four variables of FE and different structures of brain volume and cortical thickness. The results suggest that education seems to be a feature of cognitive reserve in mild TBI. Together, these studies contribute for answers to an important question about heterogeneity of TBI and clinical studies. Our findings reinforce the importance of group interventions constituted according to sociocultural variables and cognitive profiles, rather than sociocultural, individual and clinical variables. However, when considering case analysis, sociocultural variables seem to be important for cognitive performance and brain reorganization in mild TBI.