Abstracts

Rationale: Advances in the treatments applied to patients with drug resistant epilepsy has recently included novel forms of surgical therapy. Magnetic resonance-guided laser induced thermal therapy (MRg-LITT) is a minimally invasive procedure directed at patients with drug resistant focal seizures of temporal lobe origin with an improved safety profile. We report the results of our recent results of MRg-LITT at a single epilepsy center over the last three years. Methods: We retrospectively reviewed the records of all patients operated for epilepsy at Mayo Clinic in Florida between 2013 and 2016. Thirty patients underwent MRg-LITT by a single surgeon for drug-resistant localization-related epilepsy. Demographics included age, age at onset, gender, number of past AEDs, neuroimaging, PET, interictal and ictal EEG and neuropsychological/Wada testing. Post-operative data included hospital length of stay, outcome at last visit, perioperative complications, and length of follow-up from latest procedure. Results: A total of 32 MRg-LITT surgeries were performed in 30 patients (16 M) (2 repeat MRg-LITTs) and 1 patient undergoing additional surgical resection (left anterior temporal lobectomy) via craniotomy. Patients had a mean age at onset of 19.25 years (range 0-52 years) and had taken an average of 4.9 antiepileptic drugs prior to the mean age at operation of 45.6 years (range 17-74 years). MRI demonstrated a lesion in 27/30 patients who had MRg-LITT. MTS occurred in 19/30 patients (11= L; 6= R; 1= B/L), 3 were normal, 2 neuronal migrational disorders, 1 atrophy and 1 post lobectomy. EEG was lateralized in each case to the side of the lesion. iEEG localization was required in 3 patients with a non-lesional MRI. 87% of patients underwent laser ablation on one temporal lobe (L=20; 2 re-operation; R= 9). Two had frontal lobe MRg-LITT. 63% of the subjects were seizure free after surgery with a mean follow-up of 28.02 months (range 0.5-36 months). 83% of patients were discharged the day following surgery (3 discharged after 48 hours and 1 at 72 hours and 1 at 96 hours). Two patients experienced a visual field deficit and 2 patients had a significant memory deficit (normal MRI) and 3 had immediate peri-operative seizures. Conclusions: The temporal lobe was the most common target for MRg-LITT. Symptomatic etiologies were identified in the majority. Outcome resulted in seizure freedom in over 60% of patients. 83% of patients were discharged the day following surgery. The ease of use and degree of resource utilization makes MRg-LITT a viable surgical alternative with minimal complications. Funding: N/A