Anatomo-Electro-Functional Investigations in Rolandic and Peri-Rolandic Epilepsies: A conceptual framework for
Naoki Ikegaya1, Thandar Aung2, Arka N Mallela3
1Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, United States; Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan.
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.
