Real-Time Functional Mapping With Electrocorticography in Pediatric Epilepsy

Abstract

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.

CortiQ-based Real-Time Functional Mapping for Epilepsy Surgery

“…In our previous study (Korostenskaja et al, 2013), we provided qualitative evidence of concordance between RTFM, ESM, and fMRI results. This study confirms concordance between these functional mapping modalities with quantitative results.…”

“…Other RTFM software requires a 6-minute baseline period, during which the patient must remain still with minimal distractions (Korostenskaja et al, 2013). These requirements are difficult to achieve in epilepsy monitoring units, especially with pediatric patients and patients with intellectual disabilities.…”

“…One such method is SIGnal modeling for real-time identification and event detection (Schalk et al, 2008). It has been used in real-time mapping of motor function (Brunner et al, 2009) and language function (Korostenskaja et al, 2013;Roland et al, 2010). We demonstrated the first application of paradigms used in functional magnetic resonance imaging (fMRI) and electrical cortical stimulation mapping (ESM) studies for shared functional cortical mapping in the context of RTFM in pediatric patients with epilepsy (Korostenskaja et al, 2013).…”

“…It has been used in real-time mapping of motor function (Brunner et al, 2009) and language function (Korostenskaja et al, 2013;Roland et al, 2010). We demonstrated the first application of paradigms used in functional magnetic resonance imaging (fMRI) and electrical cortical stimulation mapping (ESM) studies for shared functional cortical mapping in the context of RTFM in pediatric patients with epilepsy (Korostenskaja et al, 2013). Results from all three functional modalities were qualitatively compared, demonstrating the feasibility and usefulness of a new RTFM stimulation paradigm (block design in fMRI) implementation during presurgical evaluation.…”

Bilateral intracranial EEG with corpus callosotomy may uncover seizure focus in nonlocalizing focal epilepsy

“…The extensive coverage also allowed comprehensive brain functional mapping for preventing possible neurological deficits from surgical intervention. 21 Another advantage of applying broad incision with extensive coverage is that seizure onset zones can be easily delineated without additional surgery for larger coverage or reposition of iEEG electrodes. 22 Because the procedure requires a minimum of 3 surgeries including final surgical treatment, we tried to avoid any other additional surgery which might increase the chance of complications and extension of hospital stay.…”