Stereotactic MRI-guided laser interstitial thermal therapy for extratemporal lobe epilepsy

• Authors: Kunal Gupta, Emory University; Brian Cabaniss, Emory University; Ammar Kheder, Emory University; Satyanarayana Gedela, Emory University; Paul Koch, Emory University; Kelsey C Hewitt, Emory University; Abdulrahman Alwaki, Emory University; Christopher Rich, Emory University; Supriya Ramesha, Emory University; Ranliang Hu, Emory University; Daniel Drane, Emory University; Robert Gross, Emory University; Jon Willie, Emory University
• Journal Title: EPILEPSIA
• Volume: Volume 61, Number 8
• Publisher: WILEY | 2020-08-10, Pages 1723-1734
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1111/epi.16614
• Subjects: Health Sciences, Medicine and Surgery
• Keywords: Science & Technology; Life Sciences & Biomedicine; Clinical Neurology; Neurosciences & Neurology; Engel classification; epilepsy surgery; extratemporal lobe epilepsy; laser interstitial thermal therapy; low voltage fast activity; stereoelectroencephalography; AMYGDALOHIPPOCAMPOTOMY; RESECTION; ABLATION; ONSET

Abstract

Objective: Magnetic resonance imaging (MRI)–guided laser interstitial thermal therapy (MRg-LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg-LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. Methods: We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg-LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data ± stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. Results: Thirty-five patients with mean epilepsy duration of 21.3 ± 12.2 years underwent MRg-LITT for focal ETLE at a mean age 36.4 ± 12.7 years. A mean 2.59 ± 1.45 trajectories per patient were used to obtain ablation volumes of 8.8 ± 7.5 cm3. Mean follow-up was 27.3 ± 19.5 months. Of 32 patients with >12 months of follow-up, 17 (53%) achieved good outcomes (Engel class I + II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P =.02). Of 13 patients showing favorable seizure-onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths—two seizure-associated and one suicide—were unrelated to surgical procedures. Significance: MRI-guided laser interstitial thermal therapy (or MRg-LITT) was well-tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure-onset patterns on SEEG predicted higher likelihoods of success.