Deep brain stimulation of the anterior nucleus of the thalamus for drug-resistant epilepsy: Long-term efficacy and outcomes from a prospective cohort

Aim The anterior nucleus of the thalamus (ANT) has been one of the deep brain stimulation (DBS) targets for drug-resistant epilepsy. This study aims to investigate the control of seizures among patients with ANT DBS for epilepsy. We have pioneered DBS for epilepsy in Hong Kong since 2015 and this study aims to report the long-term outcomes from a prospective cohort. Methods This is a prospective cohort study of ANT DBS for adult patients with drug-resistant epilepsy, who are unsuitable for resective epilepsy surgery. Results Six patients (3 females and 3 males, mean age 31.3) received bilateral ANT DBS in a tertiary university hospital from 2015 to 2018 (one in 2015, two in 2017 and three in 2018). Both frontal transventricular and parietal approaches were used. The active contacts were selected based on the closest Euclidean distance to the mammillothalamic tract and ANT junction. Five of the six cases (83.3%) achieved greater than 50% reduction in seizures after the operations. The median percentage of reduction in seizures was 58.5% at 3 years after DBS (range, 32.7%-80%). Overall, there was a trend of improving seizure control rate from year 1 to year 6 after the ANT DBS operations. Conclusions This is the first report of ANT DBS for drug-resistant epilepsy in Hong Kong. The results are encouraging. ANT DBS for drug-resistant epilepsy is effective and sustained in long term. The treatment option of ANT DBS should be considered in suitable candidates with drug-resistant epilepsy in our locality.