Abstracts

Rationale: In mesial temporal lobe epilepsy patients, whose are surgical candidates, Functional Magnetic Resonance Images (fMRI) contributes to establish the dominant hemisphere for language and to approximate its anatomical location. In addition, it is considered a valuable tool for memory assessment. The aim of the present study is to apply the proper methodology to analyze memory and language in this group of patients. Methods: We selected 17 patients (p.) with refractory temporal lobe epilepsy, surgical candidates. All patients presented a mesial lesion on MRI. They were evaluated before surgery, except in one case were we could performed a post-surgical evaluation. All patiens were assessed with the following paradigms: Language: written sentences comprehension, pictures naming, and verbal fluency. Memory: We evaluated episodic memory through encoding tasks. We included figures learning, new condition recognition, and a semantic decision task. Evaluations were performed in two sessions with a previous training. Results: Language localization was obteined on 100% of cases. Eighty two percent (14 p) has left fronto-temporal activation and 18 % of cases (3p), presented bilateral activation. Memory: On 23.5% (4 p.) we observed unilateral activation on the mesial region, in 1 case was correlated with the epleptogenic zone, and on the rest 3 p, activation was contralateral to the lesion. On 41% of cases (7 p.), we observed activation of both hemispheres. On 29% (5 p). we could not obteined activation with the paradigm used. On the surgical case, we observed bilateral mesial activation before and after surgery. Conclusions: With the used paradigms we achieved to localize language areas, memory function was less defined. This noninvasive method is promissory for human cognitive functions research. It is essential to have greater number of patients to obtain more determining results.