Evaluation of sensory systems in patients with drug-resistant mesial temporal lobe epilepsy undergoing surgical therapy

Abstract

By its anatomical relationship with temporal lobe, auditory and visual pathways are susceptible to anatomical or functional changes after surgical resection of temporal lobe used as a therapeutic option in patients with mesial temporal lobe epilepsy drug-resistant (ELTm-FR). We studied a sample of 28 patients with ELTm-FR operated at the International Center of Neurological Restoration between 2002 and 2012, in order to evaluate possible changes of auditory and visual sensory systems secundary to the anterior temporal lobectomy guided by electrocorticography. It was noted the existence of functional abnormalities in auditory and visual sensory systems before surgical intervention in comparison with a group of healthy subjects. After resection were detected changes in the functioning of the auditory pathway through the use of auditory evoked potentials, probably mediated by an indirect effect and long-term removal of specific structures such as the amygdala and the middle temporal pole structures. In the visual pathway resection of epileptogenic zone prompted visual field defects that were evidenced by the techniques of visual evoked potentials with stimulation by quadrants in combination with perimetry, and which corresponded to the magnitude of the neocortical tissue removed. The visual pathway lesion could be substantiated through the tractography of optic radiation and the state of its connectivity. These results should be considered for the evaluation of patients with ELTm-FR who undergo surgical treatment.