Does deep brain stimulation of the anterior nucleus of the thalamus represent the future of Lennox-Gastaut syndrome?

Background: Some studies have indicated that deep brain stimulation (DBS) of the thalamus targeting the centromedian nucleus (CMN) may reduce the frequency of seizures in Lennox-Gastaut syndrome (LGS), albeit with incomplete results. DBS targeting of the anterior nucleus of the thalamus (ANT) has demonstrated efficacy in refractory focal epilepsies and is currently FDA-approved for adult treatment. Additionally, the ANT nucleus is morphologically larger than the CMN, facilitating precise targeting and with potentially higher implantation success rates.

Patients and methods: Three adult patients (one male, two females), all experiencing daily seizures that included episodes of falling, underwent ANT-DBS, one at the age of 22 years, and two at 28 years. Two electrodes were implanted under general anesthesia, using intra-operative MRI and a micro-endoscope. The clinical data regarding seizure frequency and severity, as well as cognitive function and adaptive behaviors, were collected prospectively.

Results: One patient achieved seizure freedom 3 years post-surgery. This was confirmed by a current follow-up of 8 years after DBS, which represents a total seizure-free period of 5 years. Two patients were followed for 18 and 24 months, respectively; both achieved a seizure reduction of over 75%. All three patients demonstrated considerable improvements in adaptive behavior. No side effects (in particular psychiatric disorders) were observed with the applied therapeutic stimulation parameters.

Conclusion: This series showed promising results in adult patients with LGS for both improvement of seizure frequency and adaptive behavior. The current use of pediatric thalamic stimulation is limited but the benefits shown in adults present promising prospects for its future application.