Abstracts

Rationale: In one of the first attempts to investigate the semantic memory of children with TLE, our group demonstrated that children with mesial temporal sclerosis (MTS) had worse performance in this cognitive function than healthy children (Rzezak et al., 2011). The role of the hippocampus in episodic memory is well established. It remains to be described whether the hippocampus also have an essential part in the semantic memory of children with TLE. Our hypothesis is that patients with MTS would not have worse performance than non-MTS patients in semantic memory tests. In order to test this hypothesis, we evaluated semantic and episodic memory deficits in children with mesial temporal sclerosis (MTS) compared to non-MTS children) Thus, the aim of this study was to analyze semantic and episodic memory deficits in children with mesial temporal sclerosis (MTS) compared to non-MTS children. Methods: For this purpose, 19 consecutive children with MTS and adolescents, mean age of 11.46 years (range: 8-16, SD:±2.06) and a mean estimated IQ of 97.79 (range: 80-135, SD: 13.16) were evaluated and their performances in five tests for episodic memory (evaluating short and long-term memory and learning for verbal and visual stimuli) and in four tests for semantic memory was compared to those of 17 non-MTS children (temporal dysplasia, temporal tumor, temporal tuber, temporal cysts and temporal cavernoma) with a mean age of 12.12 (range: 8-16, SD: ±2.47) and a mean estimated IQ of 101.47 (range: 83-122, SD: ±13.48). Patients' performances on memory tests were compared with ANCOVA using age as a covariate. Results: Patients with MTS had worse performances in immediate verbal episodic contextualized memory (Story Memory I, p:0.04 and d=0.75), immediate visual episodic contextualized memory (Design Memory, p:0.012 and d=0.95), and in verbal and visual learning (Verbal and Visual Learning I, p:0.010, d=0.97 and p:0.040, d=0.78). Patients with MTS and non-MTS did not differ in any semantic memory test. Conclusions: Our data confirm the role of the hippocampus in contextualized immediate verbal and visual memory and in learning abilities as patients with MTS had a worse performance than non-MTS patients in these neuropsychological testes. By the other hand, it does not speak in favor of the role of hippocampus in semantic memory. As previously demonstrated, children with MTS had worse performance in semantic memory compared to healthy controls. It may be hypothesized that other variables, besides the structural damage to the hippocampus, can influence the presence of this type of deficits in childhood MTS. One possible explanation of our findings is the participation of the lateral temporal structures in semantic memory.