MRI-guided laser interstitial thermal therapy in epilepsy: indications, technique and outcome in an adult population. A single-center data analysis

Abstract

Background: Magnetic Resonance Imaging guided Laser Interstitial Thermal Therapy (MRIgLITT) is a promising treatment for drug-resistant epilepsy (DRE) and an alternative to open surgery. However, the relationship between clinical and radiological factors and postoperative outcomes is unclear. This study explores the indications, technical challenges, and outcomes of MRIgLITT in terms of seizure control and cognitive changes across various pathologies. Methods: A retrospective single-center analysis included 32 MRIgLITT procedures performed between January 2019 and December 2023. Procedures used the Visualase® system for laser ablation, with stereotactic robotic guidance for fiber placement. Data included demographics, clinical and surgical details (ablated volume, timing, power and accuracy), and postoperative follow-up assessed seizure outcomes and complications. Cognitive changes were analyzed using a Reliable Change Index (RCI) before and one year after the procedure. Results: The 32 procedures involved 28 patients with MRI-diagnosed pathologies: 14 hippocampal sclerosis (HS), 7 hypothalamic hamartoma (HH), 3 focal cortical dysplasia (FCD), 2 periventricular heterotopia (PVH), 1 tuberous sclerosis complex (TSC), and 1 low-grade glioma. Some cases required multiple approaches. Postoperative follow-up averaged 33 months. Among HS patients, 71.42% achieved Engel I, and 21.43% Engel II. In HH, 85.7% initially became gelastic seizure-free, with complete freedom after additional treatment. Engel I outcomes were 28.6%, while 57.2% showed significant improvement (Engel I + II). FCD patients had a 66.6% Engel I success rate. One PVH patient became seizure-free, while the TSC patient was Engel III at last follow-up. RCI analysis showed that 71.44% of patients experienced cognitive stability (RCI > -1.64) or improvement (RCI > 1.64) at one-year post-procedure. Conclusions: MRIgLITT is a safe, minimally invasive alternative for epilepsy surgery, offering quicker recovery and showing better performance preserving cognitive function. It is particularly effective for deep or complex epileptic foci and patients who might refuse open surgery.