Laser Ablation Therapy for Drug Resistant Epilepsy Is Safe, Effective

Jerry Shih, MD

A new multicenter study investigated 1-year outcomes of minimally invasive surgical treatment with laser interstitial thermal therapy (LITT) and found it to be a safe and effective treatment option for patients with drug resistant epilepsy (DRE).

At 1-year follow-up, 64.3% (n = 27; 95% CI, 48–78.5) of patients in the cohort were free of disabling seizures (reaching Engel I on the Surgery Outcome Scale) and over 95% of patients had worthwhile seizure reduction (Engel I-III). The median length of stay after LITT was 32.7 hours, and head pain at discharge averaged 1.4 (standard deviation [SD], ±2.1) on a scale from 1 to 10. Seizure worry (P = .0219) and social functioning scores (P = .0175) improved significantly at 1-year follow-up after treatment as measured of the Quality of Life (QoL) in Epilepsy questionnaire (QOLIE-31).¹

Principal author Patrick Landazuri, MD, director, Epilepsy Fellowship Program, department of neurology, University of Kansas, and colleagues stated that “this initial reporting of an ongoing prospective multicenter study presents further data in support of LITT as a surgical treatment for DRE. Our procedural and safety data continue to indicate LITT as a well-tolerated and safe treatment option… The primary success of LITT remains in well localized lesions/localizations such as mesial temporal lobe epilepsy/mesial temporal sclerosis (MTLE/MTS), cortical dysplasia, and hypothalamic hamartoma.”

The authors of the study, including Jerry Shih, MD, Director, Epilepsy Center, UC San Diego Health, examined the 1-year outcomes of patients enrolled in the multicenter, prospective LAANTERN registry (Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System; NCT02392078) specifically for epilepsy treatment. They looked at the 60 LITT procedures performed for DRE. Patients with MTLE/MTS made up 56.7% (n = 34) of the procedures, with the other procedures performed on patients with stereoencephalography target/seizure focus, focal cortical dysplasia, hypothalamic hamartoma, cavernoma, heterotopias, and tuberous sclerosis.

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There was no statistical difference between Engel I outcome between MTLE/MTS patients and patients with other epileptic etiologies (P = .1642). Two patients (4.8%; 95% CI, 0.6–16.2) had an Engel IV outcome of no meaningful reduction of seizures. Patients who reached Engel I or II outcome were defined as “responders.” Previous anterior temporal lobectomy (ATL) to the LITT target was found to be a negative predictor of Engel I or II outcome, making up 6.5% (95% CI, 10.9–69.2) of responders and 36.4% (95% CI, 10.9–69.2) of non-responders (P = .0321).

The median baseline of QOLIE-31 was 51.7 (range, 8.7–77.3) before LITT and increased by 14.1 points to 55.8 (range, -48.9 to 58.1) after 1-year follow-up, with 73.4% (n = 21; 95% CI, 52.8–87.3) reporting an improvement of quality of life. This total score change was not statistically significant (P = .2173), but previous work suggests that an 11.8-point difference indicates a clinically meaningful change. Seizure worry and social functioning scores drove the increase in total point scores.

Soon after LITT, 5 procedure-related adverse events (AEs) did occur, 1 classified as serious. Headaches occurred in 2 patients, 1 of which also experienced nausea and dizziness. Another patient had a 3 mm right convexity subdural hematoma related to LITT. All 3 of these AEs resolved without intervention. A fourth patient had mild aphasia and headache and continued to suffer mild paraphasias at 1-year follow up. The last patient had 2 LITT procedures after seizures did not initially abate. The second resulted in an intraparenchymal hemorrhage that was immediately treated but resulted in right hemiparesis and expressive aphasia that required rehabilitation. At 1-year follow-up, the fifth patient’s neurological exam returned to baseline.

"Though epilepsy surgery is a highly effective treatment for select patients with drug resistant epilepsy, it continues to be underutilized, possibly due at least in part to patient and physician concern of surgical risk," Landazuri said in a statement.² "The availability of minimally invasive options for patients is an important step forward as suggested by our finding that 84% of patients in this study indicated to their physicians, a preference for a minimally invasive option for their epilepsy surgery."

REFERENCES

1. Landazuri P, Shih J, Leuthardt E, et. al. A prospective multicenter study of laser ablation for drug resistant epilepsy – One year outcomes. Epilepsy Res. 2020; 167. doi: 10.1016/j.eplepsyres.2020.106473
2. Monteris medical announces publication of first prospective multicenter study of minimally invasive laser ablation for drug resistant epilepsy. News release. Monteris Medical. November 10, 2020. Accessed November 12, 2020. https://www.prnewswire.com/news-releases/monteris-medical-announces-publication-of-first-prospective-multicenter-study-of-minimally-invasive-laser-ablation-for-drug-resistant-epilepsy-301169856.html