THE CLINICAL-DIFFERENTIATION OF SEIZURES ARISING IN THE PARASAGITTAL AND ANTEROLATERODORSAL FRONTAL CONVEXITIES

The ictal clinical manifestations of 40 patients with frontal lobe epilepsy who became and remained seizure free after selective removal of the parasagittal or anterolaterodorsal convexities were studied. Seizures arising from the parasagittal region were characterized by a high incidence of somatosensory auras (60%) and by tonic and/or clonic motor behavior (100%) and never exhibited automatisms. Conversely, the anterolaterodorsal convexity group never showed somatosensory auras but often had warnings more typical of temporal lobe seizures, only displayed partial motor seizure activity in half the cases, and included a relatively high incidence of automatisms (30%). These clinical differences may be useful in the localization of frontal lobe epileptogenic foci. The manifestations of anterolaterodorsal convexity seizures may reflect frequent spread to the temporal lobe, whereas parasagittal convexity seizures often show initial ictal behavior, in keeping with seizure activity in that region. Early ictal unilateral head turning without other motor manifestations was seen in 3 of 10 patients in the parasagittal convexity group and in 9 of 30 patients in the anterolaterodorsal convexity group. In 11 of these 12 cases, the head turning was contralateral to the surgical removal. © 1990, American Medical Association. All rights reserved.