Long-term seizure reduction in generalized epilepsy after anterior nucleus of the thalamus stimulation

In 2018 the FDA approved the use of anterior nucleus of the thalamus (ANT) deep brain stimulation (DBS) for focal epilepsy in response to the results of the Stimulation of the Anterior Nucleus of Thalamus for Epilepsy (SANTÉ) double-blind randomized controlled trial. While generalized epilepsy (GE) was never assessed in this trial, subsequent follow up clarified that focal to bilateral tonic-clonic seizures were reduced in these subjects. In rare cases ANT DBS has nonetheless been pursued for patients with GE.

We report a 27-year-old male with idiopathic GE who was successfully treated with ANT DBS. Prior to DBS, the patient typically had three or four generalized tonic-clonic seizures (GTCS) per week, amongst other seizures, and was refractory to both medication and vagal nerve stimulation (VNS). We also systematically reviewed the literature to understand the extent to which ANT DBS has been used in GE, under what circumstances, and with what results.

Five years since the introduction of ANT DBS, the patient has remained free of GTCS. Over this time, other seizures were also markedly reduced. For the systematic review, a comprehensive literature search using PubMed, Cochrane, and Google Scholar identified 23 GE patients treated with ANT DBS across 13 publications. 13 patients had patient-specific seizure outcomes reported. Clinical findings, seizure characteristics, and outcomes were summarized, demonstrating that ANT DBS surgery typically occurred after failed VNS and was usually effective, including 3 patients who became free of GTCS.

This anecdotal evidence of effectiveness suggests that some GE networks can be modulated by high-frequency stimulation at the ANT node. When established therapies have failed, ANT DBS is a therapeutic option, but the treatment requires further structured research in treating GE.