Abstracts

Rationale: Benign focal epilepsy of childhood with centrotemporal spikes (BECTS) is a common epilepsy syndrome in children. Seizures are often seen in early school age, and many children have spontaneous resolution of seizures during the second decade of life. In BECTS, sleep potentiated spikes are seen in central and temporal EEG leads, with characteristic morphology. The natural history and clinical significance of the spikes are not established. Spikes may be a biomarker of the clinical course, as spikes may resolve or decrease when seizures resolve. In this study, we quantified centrotemporal spikes in typical BECTS, and correlated the frequency with the child's age.Methods: The study was approved by the institutional board at Boston Children’s Hospital. From July 2010 to June 2013, we continuously reviewed children with BECTS, who had EEG studies during awake and sleep; all children in the study were identified based on clinical seizure semiology and sleep potentiated centrotemporal spikes on EEG. Children with structural brain abnormalities, focal neurological deficits, known other neurological disorders and pre-existing developmental delay were excluded, as such may suggest underlying encephalopathy beyond typical BECTS. EEG was recorded using standard 10-20 international system. Sections with electrode artifact from movement were removed. Recording from stage I and stage II sleep were extracted for spike quantification. Clinical information was assessed for demographics, and antiepileptic medications at the time of the EEG. When spikes were seen in bilateral hemispheres, spike frequency was assessed for each hemisphere.Results: 35 children were identified with BECTS (mean age 9.0 years), including 21 boys (mean age 9.4 years), 14 Girls (mean age 8.6 years). 5 had bilateral centrotemporal spikes. 16 were on antiepileptic medications (mean age 9.2 years): 14 were treated with oxcarbazepine alone, one was treated with levetiracetam alone, and another was treated with combination of oxcarbazepine and levetiracetam. 19 children who were not taking any antiepileptic medication at the time of the EEG, had a mean age of 8.9 years. Children were further divided into subgroups of age of the child (in years), and mean spike frequency of sleep (stage I and II combined) was compared; mean spike frequency for the whole group was 23.9 spikes per minute. Spikes were more frequent at ages 8 years (mean 24.9 spikes/minute), 9 years (mean 28.2) and 10 years (mean 25.5), and less frequent at ages at of 6 years (mean 13.8),7 years (mean 17.2) and 11 years (mean 22.3) (table).Conclusions: In BECTS, children often present with clinical seizures, typically around 8-9 years of age. At ages of 8-10 years, we found that spikes are seen in stage I and II sleep at a higher frequency of 25-28 / minute, compared to other ages. The age of such peak spike frequency, may correlate with the age that children tend to have clinical seizures. Larger scale studies are necessary to accurately assess the correlation between the timing of maximal spike frequency and age of maximum frequency of clinical seizures.