Responsive Neurostimulation for Treatment of SCN1A-Associated Developmental and Epileptic Encephalopathies

Dravet syndrome and other SCN1A-associated epilepsies are developmental and epileptic encephalopathies with high seizure burden and frequent status epilepticus despite modern antiseizure therapies. Evidence for responsive neurostimulation (RNS) in SCN1A-spectrum epilepsy remains limited.

We performed a multicenter retrospective clinical observation of six individuals with genetically confirmed SCN1A-spectrum epilepsy treated with RNS (five Dravet syndrome, one with genetic epilepsy with febrile seizures plus).

Five patients underwent network-targeted bilateral thalamic depth lead implantation (four centromedian, one anterior nucleus) and one received frontal cortical strip leads based on individualized localization. Duration of activated stimulation ranged from 7 to 63 months. Seizure response at last follow-up was heterogeneous: one patient achieved >90% reduction, three achieved 50-90%, one achieved 1-49%, and one had no meaningful reduction (67% responders, ≥50% reduction). Notably, one patient had >9 months of seizure freedom and another had complete resolution of myoclonic-atonic seizures at most recent follow-up. Caregivers frequently reported improvements beyond seizure frequency, including reduced clusters/status epilepticus, decreased rescue and acute-care utilization, improved participation, and shorter postictal recovery. Patient 5 had stimulation-related paresthesia that resolved with reduction in stimulation frequency. Otherwise, no device- or stimulation-related complications were observed.

These descriptive findings suggest that RNS, particularly thalamic targeting, may be a palliative consideration for select SCN1A-spectrum patients while underscoring variable benefit and the importance of multidimensional outcome assessments.