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

Objective: 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.

Methods: 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).

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

Conclusions: 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.