Abstracts

Rationale: Benign Rolandic Epilepsy (BRE) is a common pediatric epilepsy syndrome. It is now known that that this population is vulnerable to various cognitive problems despite preserved overall intelligence. We evaluated neuropsychological functioning and EEG in children with BRE to determine association between interictal epileptiform discharges (IEDs) and cognition. We hypothesized that higher frequency of IEDs would correlate with greater degree of cognitive dysfunction. Methods: The study was approved by the institutional board at Boston Children's Hospital. Thirty-eight children ages 6-11 (mean=9; 24 boys, 14 girls) with neurological history of BRE (N=35) or BRE trait (without clinical seizures: n=3) were recruited from clinical databases. All children had clinical care at Boston Children's Hospital. These children were identified based on clinical seizure semiology and EEG findings with sleep potentiated centrotemporal spikes. Children who had structural brain abnormalities, focal neurological deficits, known other neurological disorders and pre-existing developmental delay were excluded. Sixteen were taking prophylactic antiepileptic drugs (AEDs). Participants with seizures (35) had a mean of 0.97 seizures per month (range 0.02 - 8) Neurocognitive assessment included parent questionnaires and child testing. Routine sleep deprived outpatient EEGs were analyzed, with manually editing to remove artifact. The mean recording time without artifact was 24 minutes. Frequencies of IEDs were quantified per minute, in the awake and asleep states. Pearson correlations between select cognitive measures and IEDs for the edited recording time were calculated separately for bilateral and independent left and right hemispheres. Results: Vocabulary knowledge was strongly negatively associated with more frequent left hemisphere IEDs (p<0.01) and bilateral IEDs (p<0.05) but not right hemisphere IEDs. Reading rate and accuracy along with rapid visual naming, a predictor of reading success, were significantly negatively correlated with left hemisphere IEDs (p<0.05) but not right hemisphere or bilateral IEDs. Nonverbal reasoning and math problem solving skills were not significantly associated with bilateral, right or left IEDs. Conclusions: Our preliminary findings suggest that the higher frequency of IEDs over the left centrotemporal region the greater the dysfunction in language based knowledge and learning, while nonverbal reasoning and mathematics skills were not associated specifically with increased IEDs in either hemisphere. Children with BRE and predominantly left hemisphere frequent IEDs may be more vulnerable to language based learning disorders. Further investigations are necessary to better delineate the risk of cognitive dysfunction in this population. The Study was funded by the CRP Pilot Grant award, Clinical Research Program, Boston Children's Hospital