Targeted Thalamic Stimulation Superior at Modulating Epileptiform Activity in Individuals with Focal Epilepsy
Study results published in Nature Communications demonstrated a reduction in cortical interictal epileptiform discharge (IED) and seizure frequency in individuals with drug-resistant focal epilepsy receiving treatment with targeted thalamic stimulation. According to the authors, these data support thalamic nucleus selection based on patient-specific thalamocortical connectivity to optimize neuromodulation in individuals with focal epilepsy, although additional studies are needed to confirm the efficacy of this approach and inform device programming.
The study included data from 41 individuals with drug-resistant focal epilepsy who underwent stereoelectroencephalography (SEEG) for epilepsy monitoring and identification of a seizure onset zone (SOZ). Researchers used a hodologic matching strategy (ie, targeting thalamic nuclei with precise anatomic and functional connections) to map 3 thalamic subnuclei to SOZ locations: pulvinar nucleus for posterior-quadrant/temporal, anterior nucleus for frontal/temporal, and ventral intermediate/oral posterior (VIM/VOP) nucleus for rolandic. A total of 274 spontaneous seizures were analyzed with concurrent sampling of the thalamic nuclei and cortical SOZ. In addition, researchers retrospectively analyzed a cohort of 10 individuals who received chronic thalamic neuromodulation implants, with follow-up of up to 3 years to assess seizure frequency and durability of effect.
Thalamic stimulation resulted in a significant reduction in cortical IED rates when the SOZ was in a hodology-matched cortical region:
- IED rate of 132 vs 78 spikes/minute for the pulvinar nucleus (P<.001)
- IED rate of 144 vs 60 spikes/minute for the anterior nucleus (P<.001)
- IED rate of 132 vs 48 spikes/minute in the VIM/VOP nucleus (P<.001)
In the cohort of participants who received chronic implants (n=10), hodology-matched implants achieved a mean seizure-frequency reduction of 87.5% compared with 8.3% for unmatched targeting.
Source: Damiani A, Nouduri S, Ho JC et al. Thalamocortical hodology to personalize electrical stimulation for focal epilepsy. Nat Commun 16:9209 (2025). https://doi.org/10.1038/s41467-025-64922-w