Multinuclear thalamic targeting with human stereotactic electroencephalography: surgical technique and nuances

The authors recently demonstrated the utility of a novel multinuclear thalamic stereotactic electroencephalography (sEEG) approach to identify personalized seizure propagation networks through the human thalamus. In this study, they detail their strategy to efficiently sample the thalamus.

The authors previously showed that a multilead orthogonal transsylvian approach allows lateral-medial sampling of bilateral anterior nuclei of the thalamus (ANTs), mediodorsal (MD) nuclei, and pulvinar (PLV) nuclei, with simultaneous capture of the opercular and insular regions. They also described a novel trans-massa intermedia trajectory to sample bilateral MD nuclei with a single electrode. For a second approach to multinuclear thalamic sampling, they designed a novel long-axis trajectory for posterior-to-anterior sampling of the lateral PLV nucleus, lateral MD nucleus, and ANT with a single electrode. Superficially, this trajectory samples from the posterior inferior temporal gyrus and then the posterior hippocampus, known as seizure network nodes. Concurrent with this long-axis trajectory, the centromedian nucleus can also be targeted with the orthogonal approach, minimizing the number of electrodes required to sample all 8 of the most relevant nuclei (4 on each side).

The multinuclear thalamic sampling approaches resulted in no complications in a series of 34 patients.

This study provides a strategy and specific implementation details for these approaches to identify the thalamic seizure networks that are increasingly important in the surgical treatment of epilepsy.