Abstracts

Rationale: Evaluations of patients with refractory temporal lobe epilepsy need to consider consequences of surgery on cognitive function. Here we evaluate the impact of temporal lobectomy in cognitive function and seizure control of MTLE-HS patients with neuroimaging showing unilateral HS, but neuropsychological tests suggesting contra-lateral or bi-temporal cognitive impairment or near-normal cognitive profile. Methods: A study of 107 patients with refractory MTLE-HS submitted to surgical treatment at CIREP (Center for Epilepsy Surgery at Ribeirao Preto, Brazil). Patients were submitted to full pre-surgical evaluation. After that, all they were individually classified as concordant (n=54), discordant (n=19), bilateral temporal-lobe impaired (19), or near-normal neuropsychological profile (n=15), according with the side of HS and results of neuropsychological evaluation. Cognitive tests were Vocabulary and Block Design, Logical Memory I, Logical Memory II, Visual Reproduction I, and Visual Reproduction II of the Wechsler Memory Scale-revised, Rey Auditory Verbal Learning Test (RAVLT), RAVLT retention, and delayed recall of the RAVLT Rey Visual Design Learning Test (RVDLT), RVDLT retention, and delayed recall (30 minutes) of the RVDLT, Copy of Rey-Osterrieth Complex Figure, delayed recall (30 minutes) of the Rey-Osterrieth Complex Figure, Digit Span and Inverted Digit Span (WMS-R), Boston Naming Test, and Word Fluency (FAS). Neuropsychological pre- and post-surgical performances were evaluated using repeated-measures ANOVAs. Results: Analyses of the effect of surgery on neuropsychological tests among the four different groups showed significant differences only for patients submitted to left (dominant) temporal lobectomy. Patients submitted to right (non-dominant) temporal lobectomy had no significant deterioration in neuropsychological tests after surgery. For left temporal lobectomy, post-hoc analysis showed significant differences for Logical Memory I (p<0.04), Logical Memory II (p<0.004), and RAVLT delayed recall (p<0.04) in patients submitted to left temporal lobectomy. Near-normal neuropsychological profile patients or discordant neuropsychological profile patients (those with good left temporal lobe neuropsychological functions but right temporal lobe cognitive impairment) had a significant impairment in results of these three sub-tests after surgery. Surgical seizure control was similar in all groups. Conclusions: We observed significant differences only for patients submitted to left temporal lobectomy. Patients submitted to right temporal lobectomy had no deterioration in neuropsychological tests. For left temporal lobectomy, post-hoc analysis showed significant differences for Logical Memory I (p<0.04), Logical Memory II (p<0.004), and RAVLT delayed recall (p<0.04). Near-normal neuropsychological profile patients or those with discordant neuropsychological profile (patients with good left temporal lobe neuropsychological functions and right temporal lobe cognitive impairment) had significant impairment in results of these three sub-tests after surgery.