Polymorphism of electroencephalographic pattern in benign epileptiform discharges in childhood
Incidence and significance of benign epileptiform discharges of childhood (BECD), or rolandic spikes, have been studied in 2723 children, aged 2-15 years, with (841 patients) and without (1882) epilepsy. All the patients underwent standard electroencephalographic (EEG) study with video-EEG monitoring made in cases of epileptiform abnormalities. In the non-epileptic group, BECD frequency was 1.33%. There was a significant predominance of boys in both groups. The age of maximal BECD expression was 4-5 years in the non-epileptic group and 9-10 years--in children with epilepsy. The majority of children without seizures demonstrated different neurological and neurocognitive abnormalities, such as chronic headaches (25%), attention deficit hyperactivity disorder (25%) and speech delay (21%). Epileptiform abnormalities were observed mostly in the right hemisphere in children with epilepsy and in the left hemisphere in non-epileptic patients. There was a morphological similarity of electroencephalographic patterns in patients with rolandic epilepsy, benign occipital epilepsy, pseudolennox syndrome, Landau-Kleffner syndrome and electrical status epilepticus during slow sleep. The authors conclude that BECD are nonspecific feature of rolandic epilepsy and can occur in the broad spectrum of disturbances forming "hereditary impairment of brain maturation" group. Hereditary mechanisms involved in realization of various electroclinical features of focal brain dysfunction are suggested.