Criação de um paradigma para avaliação do hipocampo direito através da memória visual

: estudo exploratório

Abstract

Background: Temporal lobe, especially its mesial region, is crucial for processing of memory. Studies following lesions of this region have provided the material-specific theory, which suggests the lateralization of information: the dominant mesial temporal region is specific for verbal and non-dominant for visual memory. However, other investigators have failed to detect differential impairment in verbal and visuospatial tasks according to lesion laterality. One possible explanation is that the visual memory tasks used in such studies are not assessing the function because they are composed by stimuli that could be verbalized. This assessment of function is particularly important in the assessment of patients with temporal lobe epilepsy (TLE). Aim: Design a task to evaluate non-verbal memory, in a way that verbalization of the stimuli will not interfere with the memorization process. Methodology: A pretest with 23 designs was tested in 30 healthy subjects. We’ve selected 5 designs directly from pretest and created a scoring list equivalent to the subtest Visual Reproduction (V.R) of WMS-III. The Experimental Task and the V.R were administered in a sample of 3 epilepsy patients who were subject to a right hipocampectomy, and 6 controls. In a qualitative analysis we compared the performance of each patient with 2 matching controls. A statistics analysis was used to compare the amplitude of the difference present by patients and controls in the performance between tasks. Results: All participants had a poor performance in the Experimental Task than they had in V.R. However the amplitude of the difference between tasks was significantly higher in the patients group. In the Experimental task all the patients had a lower performance than matched controls. Discussion: The present investigation suggests that verbalizing stimuli seems harder in the Experimental Task than in the V.R, this could be why patients presented a higher difference between tasks than controls subjects, performing lower in Experimental task. However, because our sample size was small, this study could only guide us in that way. The Experimental Task should be profoundly investigated, lateralization capacity should be tested, standard data created and it must be validated in this kind of population, to help in clinical practice.

Date of Award	2014
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	José Góis Horácio (Supervisor)