Abstracts

Rationale: Acquisition stages of memory abilities require a good functioning of attentional processes. It is well known that patients with temporal lobe epilepsy have episodic memory impairment and these deficits have been attributed to the involvement of mesial temporal structures in declarative memory. For this reason, a comprehensive evaluation of attention is relevant, in order to elucidate whether at least part of the memory dysfunction could be related to failures in the acquisition of the data to be stored. The aim of this study was to investigate focused, selective and alternating attention of children and adolescents with TLE and to determine the impact of clinical epilepsy variables (etiology, age of onset, epilepsy duration, seizure control, number of AED and generalized seizures) in these attentional processes.Methods: For this purpose a sample of children with unilateral TLE, with age range from 9 to 16 years-old, with an IQ from 80 to 120, and no history of psychiatric and other neurological disorders was evaluated with a battery of tests for attention (Digit Span, Finger Windows, Number and Letter Memory, Matching Familiar Figures Test and Trail Making Test) and their performance was compared to healthy volunteers. Patients performances on attentional tests were compared with ANCOVA using age and IQ as covariates. The impact of clinical variables was determined using Student t test or qui-square according to the type of variable.Results: 32 children with TLE were evaluated (14 boys, mean age of 11.69 [SD 2.12] and estimated IQ of 95.94 [SD 9.46]) and their performance was compared to 21 healthy subjects (6 boys, mean age of 11.95 [SD 2.11] and estimated IQ of 100.67 [SD 10.36]). Patients with TLE had a worse performance in focused attention (Number and Letter - p:0.032), selective attention (MFFT errors - p:0.050) and in alternating attention (Trail Making B errors - p:0.015). The presence of a lesion in temporal lobe structures, age of epilepsy onset and epilepsy duration seems to determine the presence of this cognitive deficit (symptomatic TLE had worse performance than cryptogenic TLE). Attentional deficit was not related to the presence of hippocampal sclerosis. Conclusions: Children and adolescents with TLE, especially with symptomatic TLE, have attentional deficits. These impairments range from more basic attentional processes to more complex frontal-dependent ones. These findings are particularly relevant in this age group considering the hazard effects of attentional dysfunction for formal education. Early age of onset and longer epilepsy duration negatively impacted attentional processes, which in turn speaks in favor of early surgical intervention.