Exploring Sensorimotor Physiology and Cortical Mapping With Stereoelectroencephalography Electrical Stimulation.

Abstract

Summary: Stereoelectroencephalography (SEEG) has materially broadened the landscape of sensorimotor mapping by enabling access to sulcal, medial, and subcortical structures that remain largely beyond the reach of subdural electrodes (SDE). The inherent sampling bias of SDE toward gyral crests and dorsolateral cortices constrains the exploration of the central sulcus-where primary motor and sensory cortices predominantly reside-and limits insight into deeper epileptogenic networks. In routine practice, this topographic restriction is not trivial; it shapes both our hypotheses and our blind spots. SEEG addresses many of these limitations while allowing a three-dimensional, patient-tailored exploration of sensorimotor circuits that more closely reflects individual anatomy and network organization. Of particular importance is its access to medial cortices, including the supplementary motor area, sensorimotor precuneus, and cingulate sulcus-regions that often prove consequential within epilepsy networks yet are difficult to evaluate comprehensively with surface arrays. This manuscript addresses key considerations for sensorimotor exploration in both pediatric and adult clinical settings. In experienced hands, SEEG can delineate motor, sensory, and integrative areas with a degree of precision that supports identification of eloquent and negative motor regions. It yields clinically relevant information on myelination and age-dependent changes in sensorimotor pathways-issues of special importance in pediatric populations, where developmental state and network plasticity influence both mapping interpretation and surgical risk. By facilitating targeted resections while preserving critical functions, SEEG may contribute to improved surgical outcomes, particularly when epileptogenic networks intersect or approximate eloquent cortex. Compared with SDE, SEEG provides broader anatomical reach through dispersed but deep sampling. That dispersion can appear sparse on a two-dimensional rendering, yet in complex cases involving deep or medial structures, it often proves more informative than dense but superficial coverage. Ongoing innovations-including multimodal integration, cortico-cortical evoked potentials (CCEPs), advanced stimulation techniques, and AI-driven analysis-indicate that SEEG's role will continue to evolve. Its applications may extend beyond epilepsy into movement disorders and neuroprosthetics as we refine both acquisition and interpretation. Deliberate efforts to standardize protocols and address ethical considerations will be essential if SEEG is to bridge persistent gaps between sensorimotor research and clinical care. With careful stewardship, it appears poised to reshape aspects of neurologic practice rather than merely supplement existing approaches.