Abstracts

In temporal lobe epilepsy there has been growing evidence that successful surgery for seizure control may involve a tailored approach for each individual patient. The selection of surgical approach has been made on the basis of extensive invasive recordings by some schools. Other approaches have included extensive awake mapping for speech function and epileptiform activity. We have employed a strategy of only occasional invasive recordings, no awake mapping, electrocorticography and frequent pre-operative sodium amobarbital testing for speech and memory.
We have selected 17 cases where pre-operative planning and intra-operative electrocorticography led us to non-standard tailored selective or supra-selective surgical options. The goal was to assess seizure outcome in this patient population with non-standard surgery. The reasoning underlying a supraselective approach was most often the preservation of verbal memory by subtotal resection of mesiotemporal structures or receptive speech by limiting temporal neocortical resection combined with subpial transection to areas with intra-operative epileptiform activity. For these reasons, the majority of the cases considered here are left temporal cases (14 / 17). A lesion was present in 5 cases but none of the cases reported were simple lesionectomies.
Surgeries performed included selective hippocampectomy sparing amygdala , amygdalectomy sparing hippocampus, other intentional subtotal mesiotemporal resections and tailored neocortical resections and / or transactions.. All lesions were resected combined with one of the aforementioned strategies. Fifteen on 17 patients were seizure-free at one year. The two who were not had had prior invasive monitoring clearly implicating the subsequently operated temporal lobe in seizure generation but developed different frontal lobe type seizures after surgery. One of the two has been seizure-free for over 2 years following additional frontal surgery. The other is also a candidate for frontal lobe surgery.
We assessed seizure outcome in a small series of patients who had non-standard temporal lobe surgery. Seizure outcomes would suggest that if an epileptogenic network is sufficiently disrupted, results can be excellent, even with highly selective surgical strategies. It remains crucial to continue to refine strategies that will permit selecting the most minimal procedure that will effectively disrupt a particular epileptogenic network.