Abstracts

Rationale: The use of MRI-guided laser ablation of mesial temporal structures for the treatment of intractable temporal lobe epilepsy (TLE) is a novel surgical technique introduced two years ago. This procedure is less invasive than resective surgery and is associated with a very rapid recovery and potentially, with less post-surgical cognitive deficits. We review the efficacy and safety of this procedure in patients with intractable TLE in our institution.Methods: Fifteen patients with intractable TLE underwent this surgical procedure between November 2013 and January 2015. Patients were followed at one, four, 12, 24, 40, and 52 weeks after surgery and seizure frequency was investigated at each visit. Data were collected retrospectively from the electronic medical records. The minimum post-surgical follow up period was 6 months. Volumetric analysis of ablated tissue was performed in 5 patients.Results: The mean age was 43.07 +/- 12.6 years (range: 21-69), with 7 patients being > 50. Mean follow up period was 12.6 months. Pre-surgical radiological data revealed unilateral mesio-temporal sclerosis (MTS) in nine patients. One patient had bilateral MTS, but unilateral ictal focus and one had bilateral independent ictal foci, with >90% of seizures from the ablated side. One patient had a mesio-temporal cortical dysplasia, another had dual pathology with an ipsilateral focal dysplasia posterior to the left hippocampus, and two patients had TLE with normal MRI. Engle Class I was achieved in 73% of patients, and including only those with unilateral MTS in 80% of patients. Among the 15 patients, nine were free of disabling seizures (five also had no auras), and two patients had one breakthrough seizure after abruptly discontinuation of the AEDs. Three patients had 1-3 seizures over the time of one year after the surgery, and one patient had a greater than 90% reduction in seizure frequency. There were no neurosurgical or neurological complications post-surgically. Patients above the age of 50 did not have any complications. Data on outcomes of psychiatric comorbidities and neuropsychological results will be available in companion posters. Volumetric studies were conducted in five patients with no clear correlation between total volume ablated and seizure frequency outcome. Further volumetric analysis will be available at the time of the presentation.Conclusions: Laser ablation appears to offer a minimally invasive alternative to resective surgery and could be considered especially in the elderly population. Longer follow-up periods are necessary to establish long-term efficacy of this procedure.