Anatomo-Electro-Functional Investigations in Rolandic and Peri-Rolandic Epilepsies: A conceptual framework for Stereo-EEG.

OBJECTIVE

To develop a hypothesis-driven framework for stereoelectroencephalography (SEEG) exploration in the Rolandic and Peri-Rolandic (RPR) regions and enhance understanding of epileptogenic networks and their functional implications.

METHODS

We reviewed 102 consecutive SEEG cases (January 2020 - February 2024). Eight patients (median age: 38 years) with suspected epileptogenic zones (EZ) within the RPR regions were included. SEEG trajectories, electrode locations, electrical stimulation tests, and surgical outcomes were analysed.

RESULTS

An average of 14 SEEG electrodes (range: 11-19) were orthogonally implanted along seven key trajectories: a dorsal group targeting (1) the premotor cortex/pre-SMA (supplementary motor area), (2) precentral gyrus/SMA, (3) postcentral gyrus/central sulcus, and (4) postcentral sulcus/adjacent parietal lobe; and a ventral group targeting (5) the anterior mid-cingulate cortex, (6) posterior mid-cingulate cortex, and (7) posterior cingulate cortex. Electrical stimulation on 197 contact pairs across 31 electrodes revealed that 87 % (27/31) elicited sensorimotor responses. All SEEG explorations localized the EZ. All four subsequent resective surgeries led to seizure freedom, with minimal sensorimotor deficits over a mean 19 months follow-up (range: 9-33).

CONCLUSIONS

Seven key SEEG trajectories provided comprehensive RPR coverage, enabling reliable functional and EZ mapping.

SIGNIFICANCE: This anatomo-electro-functional framework rationalizes SEEG explorations and supports effective resections, enhancing surgical outcomes in RPR epilepsies.