Abstracts

Rationale: The anterior nucleus of the thalamus was first identified as an important network structure in epilepsy in the early 1980s and 1990s. The stimulation of the anterior nucleus of the thalamus in epilepsy (SANTE) trial was published in 2010 providing support for clinical use of this modality for surgical treatment of focal epilepsies. Stimulation of the anterior nucleus of the thalamus with the deep brain stimulator (DBS) was FDA approved for medically refractory epilepsy in November 2018. Barrow Neurological Institute (BNI) has been actively using this new modality in our refractory seizure patients. We present the outcomes of our patients to date. Methods: We reviewed data from between May 2018 and March 2019, during which time 11 patients were implanted with the DBS with the anterior nucleus of the thalamus as the target. Patients age ranged from 24 to 56 years old. Seven patients had a diagnosis focal epilepsy and four patients had a diagnosis of generalized epilepsy. All patients had the stimulator on for at least 3 months. Seizure outcomes were collected, and perioperative and other complications were reviewed. Results: The Engel Classification Scale was used to measure seizure outcomes, with Engel I-III considered worthwhile improvement. The average duration of stimulation was 5 months (3-11 months). Two patients attained Engel class I (1 patient was Ia and 1 patient was Ib). Four patients achieved an Engel class of II. Two patients attained Engel class III and there were no patients who were Engel class IV. Two patients died from non-implantation or stimulation related complications. One patient had an implant-related left frontal intraparenchymal hemorrhage. Overall, at the 11-month mark, 63% of the patients were considered to have worthwhile improvement with the DBS. Overall morbidity and mortality was estimated at 27%. Conclusions: Bilateral stimulation of the anterior nucleus of the thalamus is an effective treatment in patients with the refractory epilepsies. However, this procedure can carry a risk of significant morbidity and mortality, even when performed by an experienced surgical team. Our implanted patients represent highly refractory patients with epilepsy, which may in part explain the high complication rate noted in our series. The overall degree of reduction in seizures with DBS in our case series is comparable to the data published in the SANTE trial and is suggestive of worthwhile improvement with this modality. Funding: No funding