Learning and memory and its relationship with the lateralization of epileptic focus in subjects with temporal lobe epilepsy

Abstract

Background: In medial temporal lobe epilepsy (MTLE), previous studies addressing the hemispheric laterality of epileptogenic focus and its relationship with learning and memory processes have reported controversial findings. Objective: To compare the performance of MTLE patients according to the location of the epileptogenic focus on the left (MTLEL) or right temporal lobe (MTLER) on tasks of episodic learning and memory for verbal and visual content. Methods: One hundred patients with MTLEL and one hundred patients with MTLER were tested with the following tasks: the Rey Auditory Verbal Learning Test (RAVLT) and the Logical Memory-WMS-R to evaluate verbal learning and memory; and the Rey Visual Design Learning Test (RVDLT) and the Visual Reproduction-WMS-R to evaluate visual learning and memory. Results: The MTLEL sample showed significantly worse performance on the RAVLT (p < 0.005) and on the Logical Memory tests (p < 0.01) than MTLER subjects. However, there were no significant between-group differences in regard to the visual memory tests. Discussion: Our findings suggest that verbal learning and memory abilities are dependent on the structural and functional integrity of the left temporal lobe, while visual abilities are less dependent on the right temporal lobe.

Story reading with incidental comprehension and memory: left hemisphere dominance

“…LHI was impaired in relation to non-LHI in both UC and CC, with sensitivity and specificity above 70%. The findings from the present study agree with those of studies that used the narrative as a whole unit, and verbal inputs and outputs [6][7][8]10,12,20,22 , except that the left-lateralization pattern extended beyond the temporal lobe in this study. Also in line with the present findings, concerning the input, activation that was more left-lateralized was previously observed in functional studies for reading than for listening comprehension 13,21 ; and, concerning the output, a UC: uncued condition; CC: cued condition; LHI: patients with left hemisphere injury; RHI: patients with right hemisphere injury; HP: healthy participants.…”

“…Nevertheless, since narrative-specificity in brain function may arise at a hemispheric rather than at a regional level 4 , there is a need for validity studies on the role of cerebral laterality of injury in story comprehension and recall, which have been poorly investigated at a hemispheric level. This need arises also in view of the contradictory results regarding laterality and narrative processing, not only from studies on patients with brain impairments 3,6 , and especially on those with temporal lobe epilepsy [7][8][9][10][11][12] , but also from functional or anatomical studies on healthy subjects 4,5,[13][14][15][16][17][18][19][20][21][22][23] .…”

“…Bilateral involvement and the (theoretically-subtle) interactions among explicit, implicit, and working memory have been increasingly incorporated into new studies on narrative processing 4,5,16,[24][25][26][27] . In parallel, narratives as whole units, to be understood and/or remembered, have been more frequently examined in natural settings [6][7][8][10][11][12]20,22 . Other than this, they have generally been used as the reference context for interpreting experimental manipulations with the aim of assessing attention to selected story features 14,16,18,23 .…”

Cognitive and Psychological Deficits in Children with Epilepsy at the Korle-Bu Teaching Hospital in Ghana

“…There are varying studies on the cognitive and psychological deficits associated with epilepsy. Studies have revealed that epileptic children are susceptible to severe deficits in memory [9,10,11,12,13,14] and academic achievement [15,16] compared to healthy control group. Severe psychological deficits have also been found among epileptic children compared to healthy control group [17,18,19,20].…”