Benign rolandic epilepsy of childhood: topographic EEG analysis.

Topographic EEG investigation with instant voltage mapping showed maximal negativity of 'rolandic' spikes over central or midtemporal electrodes with spread to parietal or upper frontal areas, and a dipole distribution (centrotemporal negativity, frontal positivity). There was no correlation of spike amplitude or duration with spread to adjacent areas. No other focal abnormalities, such as focal slowing, occurred. Spike activity was pronounced during light sleep and was often associated with generalized spike-wave activity, and thus was a sign of functional disturbance rather than the sequelae of brain damage. A review of the literature indicates that this pattern is helpful in differentiating this from focal abnormalities due to brain lesions.