Abstracts

Seizures beginning in the inferior occipital and temporal regions are rarely described. We present two patients whose seizures began in these regions, one in the inferior occipital lobe and the other in the posterior subtemporal region. In neither patient was the region of onset suspected, but, in retrospect, the auras might have provided clues.
One patient, with bilateral temporal occipital subependymal heterotopias, had complex visual illusions as an aura before some, but not all, seizures. For example, while riding in a car, he thought he saw a moose hitchhiking beside the road, but when he turned to look at it, it was a tree. His complex partial seizures otherwise resembled typical temporal lobe seizures with oral alimentary and gesticular automatisms.
The second patient, with a history of several prolonged febrile convulsions early in childhood, had a normal MRI. Her aura consisted of rather nonspecific visual blurring. Complex partial seizures were also typical of temporal lobe seizures with unilateral dystonic posturing and automatisms on the other side.
Both patients underwent invasive monitoring for suspected mesial temporal lobe seizures with failed localization in both. There was a strong suggestion of neocortical origin, and following additional guidance from ictal SPECT studies, a second invasive EEG study documented seizure origin from the inferior occipital region in the first patient, and from the posterior medial inferior temporal region in the second patient. Both patients had successful surgery.
When patients present with various visual auras other than elementary visual hallucinations and do not have imaging evidence for seizure origin, the rarely-studied inferior temporal and occipital cortices should be considered as possible regions of seizure origin.