Switch-Off response to mid-cingulate cortex stimulation: a video case report

Abstract

Background: Electrical cortical stimulation (ECS) is commonly used during invasive presurgical evaluation of drug-resistant focal epilepsy for functional mapping and delineation of the epileptogenic zone.

Case presentation: A 31-year-old woman underwent stereo-EEG evaluation for presurgical assessment of drug-resistant focal epilepsy, likely left frontal or multifocal. During 50 Hz ECS of the right mid-cingulate cortex, a reproducible behavioural response was observed, characterised by left ear popping, head drop, eye closure, and speech/motor arrest, without loss of awareness. This semiology differed from her habitual seizures, and the region was not considered part of the presumed epileptogenic zone.

Conclusion: This case represents a rare video-documentation of stimulation-induced complex motor and behavioural response localised to the mid-cingulate cortex and supports mid-cingulate's role as connection hub for volitional control and sensorimotor integration.

Keywords: Cingulate cortex; Electrical cortical stimulation; SEEG.

Fig. 1

Stereo-EEG implantation plan showing the deep electrode position on MRI and the site of electrical cortical stimulation in the right mid-cingulate cortex. Contact sites encircled and indicated by the arrow: RmC1 (bottom) almost out in space below falx, RmC2 (middle) grey/white matter boundary, RmC3 (top) grey matter of middle cingulum cortex.