Real-Time Functional Mapping (RTFM) with ECoG in Pediatric Epilepsy surgery: Comparison with fMRI and ESM Findings: Case Study

• Published in: Clinical EEG and neuroscience Vol. 45; no. 3; pp. 205 - 211
• Main Authors: Korostenskaja, M., Wilson, A., Rose, D., Brunner, P., Schalk, G., Leach, J., Mangano, F., Fujiwara, H., Rozhkov, L., Harris, E., Chen, P.-C., Seo, J.-H., Lee, K. H.
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• ISSN: 1550-0594
• DOI: 10.1177/1550059413492960

The SIGFRIED (SIGnal modeling For Real-time Identification and Event Detection) software provides real-time functional mapping (RTFM) of eloquent cortex for epilepsy patients preparing to undergo resective surgery. The current study presents the first application of paradigms used in functional magnetic resonance (fMRI) and electrical cortical stimulation mapping (ESM) studies for shared functional cortical mapping in the context of RTFM. Results from the three modalities are compared. A left-handed 13-year old male with intractable epilepsy participated in functional mapping for localization of eloquent language cortex with fMRI, ESM, and RTFM. For RTFM, data were acquired over the frontal and temporal cortex. Several paradigms were sequentially presented: passive (listening to stories) and active (picture naming and verb generation.) For verb generation and story processing, fMRI showed atypical right lateralizing language activation within temporal lobe regions of interest (ROI) and bilateral frontal activation with slight right lateralization. Left hemisphere ESM demonstrated no eloquent language areas. RTFM procedures using story processing and picture naming elicited activity in the right lateral and basal temporal regions. Verb generation elicited strong right lateral temporal lobe activation as well as left frontal lobe activation. RTFM results confirmed atypical language lateralization evident from fMRI and ESM. We demonstrated the feasibility and usefulness of a new RTFM stimulation paradigm implementation during pre-surgical evaluation. Block design paradigms used in fMRI may be optimal for this purpose. Further development is needed to create age-appropriate RTFM test batteries.