Cognitive profile of children with newly onset benign epilepsy with centro-temporal spikes before treatment:a study of computerized cognitive testing in epilepsy

Abstract

Benign epilepsy with centro-temporal spikes (BECTs) is a common idiopathic partial epileptic syndrome in childhood, which often affect the pre-school and school-age children and a considerable proportion have comorbidity including lower academic achievement and cognitive impairment. Few studies involved the psychocognitive assessment in such a drug-treatable epileptic syndrome especially in the newly diagnosed and medications-naive group. This study aimed to investigate the cognitive characteristics of children with newly onset BECTs before treatment. Forty-one outpatients with newly diagnosed BECTs who visited the Clinic during the periods from October 2012 to May 2014 before the medications against epilepsy and 41 healthy controls recruited from regular school in Beijing during the period from July 2013 to March 2014, who matched in age and gender underwent battery testing by computerized cognitive testing in epilepsy (CCTE). The BECTs group included 41 children, 20 boys and 21 girls, mean age (8.2 ± 1.7) years, the age of onset of epilepsy 4.5-11.5 years (the age of onset <8 years in 25 cases, ≥ 8 years in 16 cases). The cognitive characteristics and associated factors were analyzed. The primary data including correct answer numbers and reaction times were analyzed by independent sample t-test between the two groups of children with BECTs and healthy controls based on SPSS 18.0 statistical software. Raw data of 9 tasks' scores collected from BECTs and healthy control children were continuous variables in accordance with normal distribution. BECTs children performed significantly worse than controls in choice reaction time ((618+158) vs. (524+254) ms), three-dimensional mental rotation (11 ± 10 vs. 18 ± 12) and visual tracing (10 ± 6 vs.15 ± 6), t=2.01, 3.03 and 3.47, P<0.05, <0.01 and <0.001, respectively.While other 6 tasks showed no significant difference between the two groups (P>0.05 for all comparisons). BECTs boys performed significantly worse than girls on simple substraction tasks compared with standard nine score ((4.7 ± 1.5) vs. (5.6 ± 1.2), t=-2.24, P<0.05). Other 8 tasks showed no significant difference between boys and girls (P>0.05 for all comparisons). Other 9 tasks showed no significant differences between the two groups of BECTs children whose age of onset was before 8 years and those who started seizure ≥ 8 years (P all >0.05). The standard nine scores of simple substraction from the three BECTs groups of dominance sides of spikes and waves during NREM showed significant difference (P<0.05). BECTs children with bilateral discharges performed significantly worse than the other two groups dominantly right or left discharges (4.7 ± 1.2 vs. 6.0 ± 1.2 vs. 4.9 ± 1.4, P all <0.05). There was no significant difference between the two groups with right and left side dominance discharges (P>0.05). Other 8 tasks showed no significant differences among the three groups (P>0.05 for all comparisons). Although EEG discharges index below 50% during NREM period, while newly diagnosed BECTs children before treatment with medications against epilepsy performed poorer on tasks of choice reaction time, three-dimensional mental rotation, and visual tracing. The two factors of male and bilateral discharges during NREM period correlate with dysfunction of simple subtraction, the mechanism needs further study and the cognitive function of epilepsy children should be evaluated and followed up, in order to provide psychologic baseline data for persistent cognitive disturbance.