The cingulate gyrus (CG) is a neocortical structure that influences complex motor, affective and cognitive behaviors. While much work elucidating cytoarchitectural subregions within the cingulate exists, research mapping CG’s functional connectivity is less common. CG’s subsurface location makes non-invasive study difficult. fMRI alone provides suboptimal temporal representation of interactions within functional networks (1). We propose a high-resolution, multimodal approach that uses electrical cortical stimulation (ECS), Electrocorticography (ECoG) and fMRI data to identify cingulate subdivisions exhibiting unique functional connectivity profiles.

We included cases in whom cingulate electrode sampling, adequate ECS and resting fMRI have been completed. We drew data from existing patient records who have undergone ECoG recordings and fMRI scans conducted per standard of care to identify epileptic focus. Electrode reconstruction was performed by SPM and BioImage Suite according to (2, 3). fMRI data were collected according to (4). When available, single-pulse 1-Hz stimulation was employed in electrophysiology-based-functional network mapping. High-frequency Granger Causality analysis of ECoG CG seeds is underway.

54 icEEG cases from 2013-2019 were screened. Cingulate electrode sampling occurred in 40.7% of cases (bilateral in 22.2%). High frequency stimulation took place in 45.4% of the cingulate cohort. In the 10 cases included, 5 CG stimulations exhibited no symptoms or seizures, while symptoms were obtained in 5 cases. 20% of CG stimulations correlated with previously reported sense of floating/lack of perception of gravitational effect, 30% with other symptoms. fMRI connectivity analysis highlighted extensive involvement of cortical-subcortical networks that were site/function-specific.

The cingulate gyrus exhibits extensive cortical/subcortical connectivity, accounting for its major role in learning and behavior modulation. The findings highlight the need to develop sophisticated neuropsychological bedside testing. We plan to complete Granger causality analysis and write up by mid-October.