Do sequential EEG changes predict atypical clinical features in rolandic epilepsy?

AIM

Although the prognosis for rolandic epilepsy is regarded to be favourable, a small proportion of cases that initially present as rolandic epilepsy evolve into atypical benign partial epilepsy (ABPE) of childhood. The purpose of our study was to determine electroencephalogram (EEG) criteria in relation to atypical seizure manifestations, and cognitive and behavioural problems in rolandic epilepsy.

METHODS

The rolandic epilepsy group consisted of 10 children (mean age 5y 6mo, SD 1y 1mo, median age 5y 5mo; six males, four females). The ABPE group comprised five children (mean age 5y, SD 1y 2mo, median age 4y 5mo; three males, two females). We recorded the number of spikes, the locations of spikes, and the duration of the spike activity. The Wechsler Intelligence Scale for Children-Third Edition or the Wechsler Preschool and Primary Scale of Intelligence, depending on age, was administered to all children at the onset of seizures and every year thereafter. The diagnosis of attention-deficit-hyperactivity disorder was made according to the DSM-IV.

RESULTS

Significant correlations were found between atypical clinical features and extended periods of high-frequency paroxysmal EEG abnormalities (>24mo after onset; p<0.01) and frontal EEG focus (>10mo after onset; p<0.003).

INTERPRETATION

A combination of spike rate and extended periods of high-frequency paroxysmal EEG abnormalities may predict the evolution of atypical rolandic epilepsy.