Cognitive flexibility impairment in temporal lobe epilepsy: The impact of epileptic foci lateralization on executive functions

Abstract

Introduction: Temporal Lobe Epilepsy (TLE) has been associated with memory impairments, which are typically linked to hippocampal and mesial temporal cortex lesions. Considering the presence of extensive bidirectional frontotemporal connections, it can be hypothesized that executive dysfunction in TLE is modulated by the lateralization of the epileptic foci. Material and Methods: A comprehensive neuropsychological executive functions protocol was administered to 63 participants, including 42 individuals with temporal lobe epilepsy (20 with right-TLE and 22 with left-TLE) and 21 healthy controls aged 20–49. Results: The results indicate that TLE patients exhibit poorer executive performance compared to healthy controls in working memory (F(2,60) = 4.18, p <.01), planning (F(2,60) = 4.71, p <.05), set shifting (F(2,60) = 10.1, p <.001), phonetic verbal fluency (F(2,60) = 11.71, p <.01) and semantic verbal fluency (F(2,60) = 9.61, p <.001. No significant differences were found in cognitive inhibition. Furthermore, right-TLE patients showed lower performance than left-TLE in set shifting (F(1,61) = 6.45, p <.05), while no significant differences were observed in working memory, planning, inhibition, and verbal fluency. Conclusions: This research emphasize the importance of considering the lateralization of the temporal lobe focus to achieve a more accurate neuropsychological characterization. The cognitive differences between left and right TLE patients highlight the need for individualized approaches in their treatment and care.