Abstracts

Rationale: Intractable epilepsy may need a surgical option for best long-term outcome. Patients had required invasive monitoring and craniotomy in the past until around 5 years ago when alternative treatments such as stereotactic MRI-guided laser ablation (SMLA) became more of an option. We wanted to look at our almost 4.5 years experience using SMLA and see if long term outcome resembled or bettered traditional resective surgery. We looked at our 31 cases with > or = 2 years post-SMLA. We include 4 patients with repeat MSLA, and look at mesial temporal, other temporal, parietal/occipital, and frontal lobe epileptic localization and long term seizure frequency post-operation in patients with lesions and without obvious structural lesions. We hypothesized an equal or improved level of seizure control compared to traditional resective surgery with craniotomy. Methods: Retrospective electronic medical records of all patients undergoing SMLA for epilepsy from November1, 2011 to June 1,2014 were reviewed (n=31). all patients were post SMLA for > 2-4.6years. These were classified compared to baseline monthly rate of seizures as Seizure and aura free or seizure free, aura reduced, > 50-90% seizure frequency reduction, or no change (or < 50% seizure reduction), The patients were then categorized based on this criteria. Patients showed 8 mesial temporal ( 6/8 MST), 8 non-mesial temporal (1/8 lesional), 8 frontal (5/8 lesional), and 7 parietal/ occipital localizations (all lesional or prior injury). If epilepsy required a second SMLA then we counted that patient from time of second ablation,.all repeated patients had improved except 1 after initial surgery with SMLA. Results: Our data shows excellent outcome parallel to or better than traditional craniotomy based resection. For mesial temporal lobe, 75%(6/8) became seizure free, 12.5% > 75% reduced seizures (1/8), and 1 no change. Other temporal lobe cases showed 50% seizure free(4/8), 37.5% > 75% reduction in seizures (3/8), and 12.5% no change(1/8). Frontal lobe cases showed 62.5% seizure freedom(5/8) 25% > 50% reduction(2/8) and 1 no change. The parietal/occipital lesions undergoing SMLA showed 16.7%(1/7) seizure free with 83.3% (6/7) > 75% seizure reduction . .Overall 52%(16/31) became seizure free, 42 % were significantly improved for > 50% seizure frequency compared to baseline, and only 6% showed no real quantitative reduction of seizure frequency. Conclusions: Long term 2-4.6 year follow up of 31 patients undergoing 34 SMLA procedures showed similar or better post-SMLA seizure reduction parallel to or better than traditional surgical series. This long term group showed best outcomes for non parietal/occipital regions, with diffuse injury, or no lesion present, while those with dysplasia or prior brain tumor removal or prior epilepsy surgery did best for achieving seizure freedom. This long term outcome experience from a single center shows that SMLA technology can provide excellent outcome comparable over time to traditional more invasive epilepsy surgery. More multicenter retrospective and prospective data should be done to further identify factors leading to good outcomes for patients intractable epilepsy. The reduced comorbidity of SMLA is also beneficial towards patient outcomes with SMLA. Funding: none