The Children’s Hospital Los Angeles Comprehensive Epilepsy Center team recently performed its first thalamic responsive neurostimulation (RNS) procedure. This technology is placed deep in the thalamus, where it continually monitors a patient’s brain waves—and can stop seizures before they even start.
Virendra R. Desai, MD, led the five-hour procedure, which was performed in a child with generalised epilepsy whose seizures had not responded to medications or a vagal nerve stimulator (VNS). The patient is doing well.
Dr. Desai is Surgical Director of the Comprehensive Epilepsy Center at Children’s Hospital Los Angeles—a Level 4 centre that offers the most advanced, highest-quality care for children with epilepsy.
Thalamic responsive neurostimulation (RNS) is emerging as a transformative treatment for patients with drug-resistant epilepsy, offering seizure reductions of up to 80%. Many patients achieve over 90% seizure reduction, particularly those who have exhausted all other options—including anti-seizure medications, vagal nerve stimulation (VNS), and dietary therapies.
Surgical Approach and Precision Targeting
Successful thalamic RNS requires precise electrode placement within a 5mm target deep in the thalamus. This is achieved through detailed preoperative imaging, including MRI and CTA scans, which guide electrode trajectory while avoiding critical blood vessels. The surgery itself is robot-assisted, ensuring accuracy within a millimetre. Postoperatively, the electrode is connected to an implantable pulse generator, delivering tailored stimulation to modulate seizure activity.
Time to Effect and Adjustability
Thalamic RNS requires a titration period, with seizure reduction typically observed within 3–6 months. The device initially records seizure activity before stimulation is activated at low settings, which are then optimised over time. Thalamic RNS is adaptable, allowing fine-tuning to individual patient needs by adjusting stimulation parameters in response to real-time brain activity.
Safety and Future Perspectives
With a surgical risk profile comparable to VNS (infection and bleeding risks <1%), thalamic RNS offers a safe, fully reversible intervention. It has the potential to replace VNS as the preferred first-line neuromodulatory option. While clinicians currently favour VNS due to its longer history, accumulating evidence may shift standard practice in favour of thalamic RNS.
For paediatric patients, epilepsy surgery decisions must weigh the risks of intervention against the long-term consequences of uncontrolled seizures—including cognitive decline, psychiatric comorbidities, and SUDEP. With growing evidence and increasing experience, thalamic RNS may redefine treatment paradigms for drug-resistant epilepsy.generalised epilepsy.
