A Posterior Approach for Combined Targeting of the Centromedian Nucleus and Pulvinar for Responsive Neurostimulation.

Abstract

Background and objectives: Neuromodulation for the treatment of epilepsy is a growing field, and several thalamic nuclei (including the anterior nucleus, centromedian nucleus [CM], and pulvinar) have been implicated and targeted. Although an anterior trajectory approach to the CM is conventionally used, we report on a novel posterior trajectory which can be useful when the conventional anterior approach is surgically challenging, or where dual CM and pulvinar coverage is desired.

Methods: Clinical and imaging data were retrospectively collected from 7 patients with at least 1 posterior trajectory CM lead and 4 patients with at least 1 anterior trajectory CM lead.

Results: Patients in the anterior and posterior trajectory groups had a mean of 48.1% and 65.2% seizure reduction, respectively, and were not significantly different (P = .53). Patients in the posterior trajectory group had contacts within the CM and/or pulvinar. There were no pulvinar contacts in the anterior trajectory group. Analysis of structural connectivity in 1 patient from each group revealed temporal- and occipital-projecting tracts for electrodes within the anterior and medial pulvinar nuclei. Stimulated thalamic nuclei from the anterior trajectory lead did not show any temporal- or occipital-projecting tracts.

Conclusion: We demonstrate that a posterior trajectory approach to the CM is feasible, safe, and effective in drug-resistant epilepsy. This provides an alternative option when the conventional anterior approach is surgically infeasible or when dual CM/pulvinar coverage is desired.