Orbitofrontal resections for intractable partial seizures

Abstract The orbitofrontal cortex has extensive connections with limbic structures that are often involved in intractable partial seizures. Although some cases of orbitofrontal epilepsy have been reported, the exact incidence and optimal means of diagnosis and treatment of this condition are not well established. For 1 year, we included recordings from the orbitofrontal cortex in all cases of limbic epilepsy that required invasive monitoring as part of a preoperative workup. We identified 3 cases in which orbitofrontal resections were performed to control intractable partial seizures. In 1 case, an orbitofrontal resection based on physiologic data disclosed an area of focal cortical dysplasia that had not been identified by preoperative structural and functional imaging. In the second case, the adjacent orbitofrontal area was resected concurrently with a dominant anterior temporal lobectomy (ATL). In the third case, a patient was seizure-free for 6 years after an ATL. The seizures recurred, however, and an orbitofrontal resection was performed on the same side as the original surgery. These patients had no unique EEG or semiology profile that identified orbitofrontal seizures before invasive recordings were made. The orbitofrontal cortex may be the source of intractable partial seizures, and this should be considered in electrode implantation strategies for the preoperative evaluation of patients with this disorder.