Language lateralisation through dichotic listening in a group of patients with temporal lobe epilepsy

Abstract

Introduction

Dichotic listening is one of the most common techniques used to determine the hemispheric lateralisation of language, using pairs of stimuli that are presented simultaneously, one in each ear to induce auditory competition between the two ears. Right-ear advantage for the perception of words is considered the most important indicator of left hemispheric lateralisation of language. Greater variability in hemispheric lateralisation has been found in patients with temporal lobe epilepsy due to mechanisms of brain plasticity.

Objective

Confirm right-ear advantage for the perception of word pairs using the dichotic listening technique in a group of right-handed patients with temporal lobe epilepsy.

Methods

A 60 word-pair dichotic listening technique was used, controlling the appearance, duration and ending of each pair of stimuli. Twenty-seven (27) right-handed patients with temporal lobe epilepsy were studied, obtaining their laterality index based on the number of words perceived in each ear.

Results

Right-ear advantage with a significant difference (p < 0.0001) was observed between both ears. According to the laterality index, 78% of the patients had left hemispheric lateralisation of language.

Conclusion

The presence of right-ear advantage for the perception of word pairs is a constant pattern that suggests hemispheric lateralisation of language in patients with epilepsy. Considering its scope and limitations, dichotic listening can be used to screen preoperative patients with temporal lobe epilepsy. There are no reports on the Mexican population on this subject.