Relation of Structural and Functional Changes in Auditory and Visual Pathways after Temporal Lobe Epilepsy Surgery.

Margarita Minou Báez-Martín ,Celia Alarcón-Calaña,Ricardo Valdés-Llerena,Bárbara Estupiñán-Díaz,Randis Garbey-Fernández,Ivette Cabrera-Abreu,M.e García-Navarro ,Karla Batista García-Ramó ,Judith González Gonzalez ,I García-Maeso ,Yamila Pérez Téllez ,Nelson Quintanal Cordero ,Rafael Rodríguez‐Rojas ,Lilia María Morales Chacón ,Juan Enrique Bender Del Busto ,Lourdes Lorigados Pedré ,Reinaldo Galvizu Sánchez

doi:10.3390/bs8100092

Margarita Minou Báez-Martín , Celia Alarcón-Calaña + Show 15 more

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https://doi.org/10.3390/bs8100092

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Abstract

Auditory and visual pathways may be affected as a consequence of temporal lobe epilepsy surgery because of their anatomical relationships with this structure. The purpose of this paper is to correlate the results of the auditory and visual evoked responses with the parameters of tractography of the visual pathway, and with the state of connectivity between respective thalamic nuclei and primary cortices in both systems after the surgical resection of the epileptogenic zone in drug-resistant epileptic patients. Tractography of visual pathway and anatomical connectivity of auditory and visual thalamus-cortical radiations were evaluated in a sample of eight patients. In general, there was a positive relationship of middle latency response (MLR) latency and length of resection, while a negative correlation was found between MLR latency and the anatomical connection strength and anatomical connection probability of the auditory radiations. In the visual pathway, significant differences between sides were found with respect to the number and length of tracts, which was lower in the operated one. Anatomical connectivity variables and perimetry (visual field defect index) were particularly correlated with the latency of P100 wave which was obtained by quadrant stimulation. These results demonstrate an indirect functional modification of the auditory pathway and a direct traumatic lesion of the visual pathway after anterior temporal lobectomy in patients with drug resistant epilepsy.

Highlights

The natural history of mesial temporal lobe epilepsy is variable; among 20% and 40% of patients have pharmacologically intractable seizures despite more than ten new antiepileptic drugsBehav
middle latency response (MLR): As a whole, we found a positive relationship between the latency of the MLR components and the length of the resection; whereas a negative one was observed with the connectivity of the auditory thalamus-cortical radiation
Epilepsy surgery as a therapeutic option for patients with drug-resistant mesial temporal lobe epilepsy (mTLE) produced structural and functional changes in the auditory and visual sensory systems, which were detected by the use of electrophysiological techniques and in correspondence with the structural variations that were evidenced with neuroimaging techniques

Summary

Introduction

The natural history of mesial temporal lobe epilepsy (mTLE) is variable; among 20% and 40% of patients have pharmacologically intractable seizures despite more than ten new antiepileptic drugsBehav. Sci. 2018, 8, 92 being added to the market in recent years [1,2,3,4] This refractoriness to medication leads to a progressive deterioration from the neurobiological, psychological and social point of view of the patients. From the anatomical and functional point of view, the temporal lobe is closely related to the auditory and visual pathways before its projection to the temporal operculum and the calcarine sulcus, respectively [7]. These pathways can be directly or indirectly affected as a consequence of surgical treatment

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