Cerebral seizures of probable orbitofrontal origin.
Four patients with seizures of presumed temporal lobe origin are presented in whom a definite focal ictal onset in the orbitofrontal cortex was revealed during recording, either by chronically implanted electrodes or ECoG. In three cases automatisms occurred concomitantly with orbitofrontal activation without spread of paroxysmal activity into the temporal structures monitored. With eight additional cases of possible orbitofrontal epilepsy found on reviewing the literature, two subgroups emerge: (1) patients with primarily psychomotor-type fits, and (2) patients with loss of consciousness, head and eye deviation, and generalized convulsions. Scalp EEGs, in patients on whom we have available data, manifested bilaterally synchronous, paroxysmal discharges which were bifrontal, frontopolar, or maximal in one anterior quadrant, with or without evidence of additional temporal lobe involvement. On the basis of anatomic and physiological studies, as well as our own electrographic data, it is felt that a posterior orbitofrontal and temporo-limbic relationship exists, within which autonomous epileptogenic zones may develop, with the ability to discharge directly and independently to subcortical centers, while eliciting similar clinical patterns.