Implications of extrahippocampal and extratemporal changes in control of seizures and the result of surgery in patients with temporal lobe epilepsy

Abstract

Mesial Temporal Sclerosis (MTS) is the most common cause of temporal lobe epilepsy (TLE), characterized by gliosis and atrophy of the hippocampus and related structures, such as the temporal pole , the mamilar body and fornix, for example. However, the brain damage is not limited to these structures, and has been described posterior temporal changes and extra-temporal damage in TLE patients. Brain atrophy and tissue loss is progressive and can be measured by quantitative MRI techniques. Atrophy has been shown in TLE patients using automatic segmentation techniques, which might be related to the seizures frequency or the use of multiples antiepileptic drugs. However, these results are still controversial. To study the existence and mechanism of the brain damage related to MTS we will use quantitative MRI techniques and post-processing to compare the surgery outcome of TLE patients with good and poor results. We endeavor to understand the changes that occur in the tissues and to correlate them with outcome and use of antiepileptic drugs. We will compare the MRI follow-up of patients with clinical treatment, either. The comparison of brain volume will be made yearly. Our epilepsy surgery center has more than 500 patients operated, and a large number of patients in clinical follow-up, beside one research dedicated 3T MRI equipment (FAPESP-CInAPCe project) and group expertise allowing this project development.