Abstract

Background: Childhood epilepsy with centrotemporal spikes (also known as Rolandic epilepsy) is one of the most frequent epileptic syndromes in childhood. Diagnosis is based on typical seizures and electroencephalographic features:

symmetric background EEG activity, well organized, with normal reactivity in wakefulness and normal sleep patterns;

interictal rolandic epileptiform discharges. Quantitative analysis of the EEG recording (QEEG) is a way of assessing the brain’s electrical activity. Compared with analog EEG, it provides additional data in neurological disorders where no structural brain damage is present, but rather an alteration of how the brain evaluates information. In epilepsy, QEEG studies are limited.

Objectives: To identify whether there are present changes in background activity, using quantitative analysis of sleep EEG, routinely obtained in the diagnostic stages, compared with a group of healthy children.

Method and subjects: We performed an observational, transversal, case-control type study, that included two groups: rolandic epilepsy patients and a control group of comparable age.

Result Relative powers were obtained for delta (0.5-3.5Hz), theta (4.0-7.5Hz), alpha (8.0-12.5Hz) and beta (13.0-30.0Hz) band frequencies, for the electrodes: FP1, FP2, F7, F8, C3, C4, T5, T6, P3, P4, O1, O2. Dominant relative power was delta band in both groups, 73.58-77.79% in the epilepsy group, and 68.11 - 78.37% in the control group, with maximum at the occipital electrodes (epilepsy group); occipital, central and frontal (control). Comparison of average delta relative power between two groups, using t test for independent samples, showed no significant differences, except for the C3 electrode (t=2.12, p<0.05), with delta relative power higher for epilepsy patients. There were no significant differences between left and right hemispheric relative power of delta, theta and alpha frequencies in epilepsy group. In terms of relative power for beta frequency, it is a dominance for the right hemisphere for pairs of central electrodes C3/C4 (1.42/1.55, t=2.32, p<0.05). Amplitudes of the background activity, in each electrode, were evaluated and compared between control and epilepsy group-for sequences provided by quantitative processing program, respectively: 9.131sec, 9.622sec, 10.132sec and 10.623sec. there were no significant differences.

Keywords: Epilepsy; Rolandic; Centrotemporal; Children; QEEG

Abbreviations: BRE: Benign Rolandic Epilepsy; NREM: Non rapid eyes movements sleep; REM: Rapid eyes movement sleep; EEG: Electroencephalography; QEEG: Quantitative EEG; ADHD: Attention-Deficit/ Hyperactivity disorder