Cognitive profiles in pediatric unilobar vs. multilobar epilepsy.

OBJECTIVES: We aimed to determine how cognitive impairment relates to the extent of the presumed epileptogenic zone in pediatric focal epilepsies. We analyzed the cognitive functions in unilobar compared to multilobar focal epilepsy patients that underwent neuropsychological testing at a tertiary epilepsy center. METHODS: We assessed cognitive functions of pediatric focal epilepsy patients with the German version of the Wechsler Intelligence Scales that measures full-scale IQ and subcategories. We assessed differences in IQ and epilepsy-related variables between unilobar and multilobar epilepsy patients. RESULTS: We included 62 patients (37 unilobar, 25 multilobar), aged 10.6 ± 3.7 years. Full-scale IQ values were significantly higher in unilobar (93.6 ± 17.7, 95% CI 87.7-99.6) than in multilobar epilepsy patients (77.3 ± 17.2, 95% CI 69.3-85.0; p = 0.001). In all but one IQ subcategory (working memory), significantly higher values were measured in unilobar than in multilobar epilepsy patients. The proportion of unilobar epilepsy patients with severe cognitive impairment (8.3%) and below-average intelligence (30.5%) was lower compared to multilobar epilepsy patients (47.6% and 61.9%; p = 0.002 and p = 0.021, respectively). Epilepsy onset occurred earlier in multilobar (4.0 years, 95% CI 2.6-5.5, SD ± 3.4 years) than in unilobar epilepsy patients (7.0 years, 95% CI 5.5-8.5, SD ± 4.4 years, p = 0.008). CONCLUSIONS: Pediatric multilobar epilepsy patients face more cognitive issues than unilobar epilepsy patients on average. Our findings should help to identify children and adolescents who are most at risk for impaired cognitive development. A limitation of our study is the simple division into unilobar and multilobar epilepsies, with no specific account being taken of etiology/epilepsy syndrome, which can have a profound effect on cognition.

Cognitive performance and behavior across idiopathic/genetic epilepsies in children and adolescents.

We investigated the cognitive and behavioral profile of three distinct groups of epilepsies with a genetic background for intergroup differences: (1) idiopathic/genetic generalized epilepsies (IGE/GGE group); (2) idiopathic focal epilepsies (IFE group); and (3) epilepsies with proven or strongly suggested monogenic or structural/numeric chromosomal etiology (genetic epilepsies, GE group). Cognitive (total IQ and subcategories) and behavioral parameters (CBCL) were assessed at the tertiary epilepsy center of the University of Munich (Germany). We used ANOVA with post-hoc Bonferroni-correction to explore significant mean differences and Fisher's exact test for significant proportional differences of intelligence impairment and behavioral problems. 126 (56 IGE/GGE, 26 IFE, 44 GE) patients were available. Total IQ was 89.0 ± 15.9 (95% CI 84.5-93.4) for IGE/GGE, 94.8 ± 18.1 (95% CI 87.3-102.3) for IFE and 76.4 ± 22.4 (95% CI 67.6-85.3) for GE (p = 0.001). The same trend was significant for all but one IQ subcategory. The rate of patients with an intelligence impairment (total IQ < 70) was higher for GE (40%) than for IGE/GGE (14%) and for IFE (7%) patients (p = 0.033). There were no significant differences between groups for behavior scores and behavioral problems. This study shows that the current ILAE classification of epilepsies with genetic etiology creates a heterogeneous group of patients with respect to cognitive performance but not behavior. These findings may help in further delineating epilepsies as regards cognitive performance, notwithstanding their closely related etiological classification.