Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy for Treatment of Drug-Resistant Epilepsy

Abstract

Surgery is the most effective treatment for drug-resistant epilepsy. Long-term studies demonstrate that about 60% to 80% of patients become seizure-free after anterior temporal lobectomy and a majority of patients (about 95%) report significant seizure reduction after surgery. In the last few years, there has been significant advances in minimally invasive surgical techniques to treat drug-resistant epilepsy. These minimally invasive procedures have significant advantages over open surgery in that they produce less immediate discomfort and disability, while allowing for greater preservation of functional tissue. Laser interstitial thermal therapy (LiTT) is an example of such a procedure. Recent advances in imaging, surgical navigation, and real-time thermal monitoring have made LiTT safer and easier to implement, offering an effective and powerful neurosurgical tool for drug-resistant epilepsy. This article will review the technical considerations, uses, and potential future directions for LiTT in drug-resistant epilepsy.

Keywords: Laser interstitial thermal therapy; drug-resistant epilepsy; epilepsy; mesial temporal sclerosis; temporal lobe epilepsy; temporal lobectomy..

Fig. 1

Applicator with diffusing tip. During thermal ablation of epileptogenic zone, the diode laser fiber is stereotactically inserted in the target tissue using a magnetic resonance imaging compatible applicator with a diffusing tip. The diffusing tip creates an ellipsoid light distribution along the axis of the 1-cm tip. Image courtesy of Visualase

Fig. 2

Postablation magnetic resonance imaging (MRI). This sagittal image shows the ablation cavity immediately at the conclusion of the procedure. A baseline T1 contrast-enhanced MRI image is generally performed on completion of treatment, though this typically overestimates the volume of ablation. It may be repeated several months later, depending upon clinical need