Abstracts

Rationale: To evaluate the incidence of and review the clinical features and EEG evolution of patients with combined benign focal discharges of childhood(BFDC). Methods: The medical files and EEG records of children with BFDC from 2000 to 2009 were retrospectively analyzed. Abnormal neurological examination or brain imaging was excluded. Results: 388 cases with centrotemporal(CTS) spikes, 54 cases with occipital spikes, 4 cases with frontal spikes, 22 cases with combined CTS and occipital spikes, 6 cases with combined CTS and frontal spikes, 4 cases with combined frontal and occipital spikes and 1 case with combined frontal, CTS and occipital spikes. Of the 22 cases with combined CTS and occipital spikes, three cases were excluded because of incomplete patient files. Age of onset of seizures varied from age 2-10 (average 5.3 y/o). Clinical features were categorized as focal (8/18, 44.4%) and generalized seizures (10/18, 55.6 %). A second EEG was done from age 3-14 (average 7.9 year of age). Of these, two EEG was normal, three EEGs showed CTS and occipital spike, four EEGs showed occipital spikes, two EEGs showed CTS spikes and one EEG showed CTS spike with generalized epileptiform discharges. A third EEG was done from age 6-19 (average 11.1 y/o). Of these, four EEGs were normal, two EEGs showed occipital spikes and one case showed CTS spikes. Of the six cases with combined CTS and frontal spikes, Seizure onset ranged from 4-9 y/o (average 5 y/o). Clinical features were categorized as focal in 2/5 and generalized seizure in 3/5. The second EEG was done from 5-13 y/o(average 10.3 y/o). Of these, 3/5 were normal, 1/5 showed frontal spikes, and 1/5 showed combined CTS and frontal spikes. A third EEG was done in one case, which EEG showed combined CTS and frontal spikes. A fourth EEG was done in this case and showed frontal spikes. Of the four cases identified with combined frontal and occipital spikes, the age of seizure onset ranged from 5-8 y/o (average 6.25 y/o). Clinical features were categorized as focal in 1/4 cases and generalized in 3/4. A second EEG was done from 7-11 y/o (average 8.7 y/o). In this group, 2/4 showed combined frontal and occipital spikes, 1/4 showed benign frontal discharges, and 1/4 showed benign occipital discharges. In this group having a third EEG, 1/2 was normal, while 1/2 showed combined frontal and occipital spikes. A fourth EEG, done in one case, was normal. The one case with combined CTS, frontal and occipital spikes had onset of seizure at 4 y/o. A second EEG showed combined occipital discharges and generalized epileptiform discharges. A third EEG showed combined CTS, frontal and occipital spikes. Conclusions: We found 7.2% incidence of combined BFDC. Average seizure onset was 5.4 year of age. Clinical features were categorized as generalized (60.7%) and focal (39.9%). EEG evolution over time indicates CTS spikes disappear before occipital spike and frontal spikes. It was not conclusive whether frontal or occipital disappear first. Future research should be conducted in a prospective fashion, including a larger patient population.