FunctionalMRI memory Mapping for epilepsy surgery planning: a case report

RESUMO

Functional evaluation of memory lateralization can have an impact of epilepsy surgery for mesial temporal lobe (MTL)epilepsy. Functional MRI (fMRI) may provide non-invasive method to assist in the determinations of memory dominance. FMRI based memory mapping, however, is still not strainghforward and determining lateralization can be difficult for a number of reasons. One oustanding question relates to the influence of material type on MTL activation. To improve pre-operative memory lateralization evaluation using an event-related fMRI paradigm. This approach was designed to take into account succeful encoding and material type. We describe here the case of a patient with MTL epilepsy who inderwent memory mapping using this new functional MRI design. For each stimulus modality, we generated maps and calculated the lateralization of the activations. The patterns encoding task was associated with the most righ-lateralized MTL activity, whereas word encoding was the brain region for different stimulus modalities that follow the overall pattern found in our previous blocked-design studies. The mapping in this case was concordant with the structural imaging and electrophysiological findings: