Pulvinar responsive neurostimulation for posterior quadrant epilepsy: an illustrative case with connectome projection

Objective To present the rationale for targeting the thalamic pulvinar nucleus with Responsive Neurostimulation (RNS) in refractory epilepsy involving the posterior quadrant, supported by connectome-based analysis and a rare illustrative case of a successful pulvinar implantation. Methods A connectome-based analysis of the pulvinar nucleus was conducted using normative diffusion imaging data from 1,065 subjects to map structural connectivity with cortical and subcortical regions implicated in seizure propagation. Insights from literature were combined with a detailed clinical case in which RNS electrodes were implanted in the pulvinar nucleus and posterior cortical regions after extensive presurgical evaluation. Results Connectome analysis demonstrated extensive pulvinar connectivity with seizure-prone regions, including mesial temporal, parietal, and occipital cortices, supporting its role in modulating corticothalamic activity. The illustrative patient, with drug-resistant posterior quadrant epilepsy not amenable to resection, underwent pulvinar and cortical RNS lead placement. At 18-month follow-up, clinical seizures were reduced to only two episodes, both associated with sleep deprivation, with ECoG evidence of aborted interictal runs by therapy. Conclusion This report underscores the thalamic pulvinar nucleus as a promising yet rarely targeted site for neuromodulation in posterior quadrant epilepsy. The combination of connectome-based targeting and successful long-term clinical outcome supports further exploration of pulvinar RNS as a treatment option for complex epilepsy cases where conventional targets may be suboptimal.