Comunicação e funções executivas pós-lesão cerebrovascular unilateral esquerda versus direita e desenvolvimento de programas de reabilitação discursiva e léxico-semântica

Abstract

The present thesis sought to assess the impact of right- and left-hemisphere damage on communicative and cognitive processes, to investigate the relationship between these functions, as well as to develop and assess the outcomes of communication rehabilitation programs. These goals were achieved through three empirical studies. The first investigation looked into the nature of and relationship between post-stroke impairments in communicative and executive functions in patients with unilateral strokes in the right versus the left hemisphere. Differences in communicative processing between the two clinical groups were investigated based on the performance of 73 patients, of whom 36 had right hemisphere damage (RHD) while 37 had left-hemisphere damage (LHD). Executive function impairments and their association with discourse processing were investigated in 42 participants, of whom 25 had RHD and 17 had LHD, using the Brief Montreal Communication Assessment Battery, the Bells Test, the Oral word span in sentences subtest from the Brazilian Brief Neuropsychological Assessment Battery NEUPSILIN, the Hayling Test and the Modified Wisconsin Card Sorting Test (48 cards). Patient performance was evaluated using Student s T-tests, as well as Chi-square tests of the number of individuals with communicative/cognitive impairment in each group, as indicated by Z scores. The two groups did not differ as to the prevalence of communicative deficits, although patients with LHD displayed slower inhibitory processing. Additionally, two cases had communicative impairments in the absence of executive deficits, while fourteen patients displayed executive function impairments only. The lack of between-group differences may be attributable to the fact that participants were assessed in the chronic stage of recovery. The presence of dissociations between impairments in the two types of processing also reveals that the relationship between these conditions is not causal. The second study involved the development and implementation of a feedback-based discourse rehabilitation program (FDRP) in a patient with TBI. The program was developed using an eight-step process, which culminated in a pilot study. Pre- and post-intervention comparisons revealed improvements in scores on part A of the Hayling test and on the full retelling of the story in the discourse task of the MAC-B Battery. A decrease in inadequate communicative behaviors such as speaking off topic was also observed over the course of the intervention. The use of pictogram-based feedback appeared to contribute significantly to the improvement of inadequate communicative behaviors. However, further studies must be performed to determine the optimal number of sessions required to obtain reliable results, as well as to assess the longterm effects of the intervention through the use of follow-up assessments. The third study involved the development of a context-based lexical-semantic rehabilitation program (CLSR). This process involved eight steps. The expert evaluation of task stimuli and instructions, and of their conformity to the intended goals, was essential for the construction of the CLSR, as was the pilot study in which the judges suggestions for improving the understandability of the tasks were implemented. Studies involving clinical groups should be performed to ensure the efficacy of this rehabilitation approach. To date, most lexical-semantic therapies have focused on the treatment of anomia, so that the present studies provide an important new perspective regarding the rehabilitation of these components. In conclusion, the studies which comprise this thesis make important contributions to our knowledge of the relationship between cognitive-communicative functions and hemispheric lateralization, as well as to the development of rehabilitation programs based on clearly defined methods.