TY - JOUR
T1 - High interictal connectivity within the resection zone is associated with favorable post-surgical outcomes in focal epilepsy patients
AU - Shah, P.
AU - Bernabei, John M.
AU - Kini, Lohith G.
AU - Ashourvan, A.
AU - Boccanfuso, Jacqueline
AU - Archer, Ryan
AU - Oechsel, K.
AU - Das, Sandhitsu R.
AU - Stein, Joel M.
AU - Lucas, Timothy H.
AU - Bassett, Danielle S.
AU - Davis, Kathryn A.
AU - Litt, B.
N1 - Funding Information:
This work was supported by National Institutes of Health grants 1R01NS099348 and K23-NS073801 . We also acknowledge support by the Thornton Foundation , the Mirowski Family Foundation , the ISI Foundation , the John D. and Catherine T. MacArthur Foundation , the Sloan Foundation , the Paul Allen Foundation , Neil and Barbara Smit, and Jonathan Rothberg .
Publisher Copyright:
© 2019 The Authors
PY - 2019
Y1 - 2019
N2 - Patients with drug-resistant focal epilepsy are often candidates for invasive surgical therapies. In these patients, it is necessary to accurately localize seizure generators to ensure seizure freedom following intervention. While intracranial electroencephalography (iEEG) is the gold standard for mapping networks for surgery, this approach requires inducing and recording seizures, which may cause patient morbidity. The goal of this study is to evaluate the utility of mapping interictal (non-seizure) iEEG networks to identify targets for surgical treatment. We analyze interictal iEEG recordings and neuroimaging from 27 focal epilepsy patients treated via surgical resection. We generate interictal functional networks by calculating pairwise correlation of iEEG signals across different frequency bands. Using image coregistration and segmentation, we identify electrodes falling within surgically resected tissue (i.e. the resection zone), and compute node-level and edge-level synchrony in relation to the resection zone. We further associate these metrics with post-surgical outcomes. Greater overlap between resected electrodes and highly synchronous electrodes is associated with favorable post-surgical outcomes. Additionally, good-outcome patients have significantly higher connectivity localized within the resection zone compared to those with poorer postoperative seizure control. This finding persists following normalization by a spatially-constrained null model. This study suggests that spatially-informed interictal network synchrony measures can distinguish between good and poor post-surgical outcomes. By capturing clinically-relevant information during interictal periods, our method may ultimately reduce the need for prolonged invasive implants and provide insights into the pathophysiology of an epileptic brain. We discuss next steps for translating these findings into a prospectively useful clinical tool.
AB - Patients with drug-resistant focal epilepsy are often candidates for invasive surgical therapies. In these patients, it is necessary to accurately localize seizure generators to ensure seizure freedom following intervention. While intracranial electroencephalography (iEEG) is the gold standard for mapping networks for surgery, this approach requires inducing and recording seizures, which may cause patient morbidity. The goal of this study is to evaluate the utility of mapping interictal (non-seizure) iEEG networks to identify targets for surgical treatment. We analyze interictal iEEG recordings and neuroimaging from 27 focal epilepsy patients treated via surgical resection. We generate interictal functional networks by calculating pairwise correlation of iEEG signals across different frequency bands. Using image coregistration and segmentation, we identify electrodes falling within surgically resected tissue (i.e. the resection zone), and compute node-level and edge-level synchrony in relation to the resection zone. We further associate these metrics with post-surgical outcomes. Greater overlap between resected electrodes and highly synchronous electrodes is associated with favorable post-surgical outcomes. Additionally, good-outcome patients have significantly higher connectivity localized within the resection zone compared to those with poorer postoperative seizure control. This finding persists following normalization by a spatially-constrained null model. This study suggests that spatially-informed interictal network synchrony measures can distinguish between good and poor post-surgical outcomes. By capturing clinically-relevant information during interictal periods, our method may ultimately reduce the need for prolonged invasive implants and provide insights into the pathophysiology of an epileptic brain. We discuss next steps for translating these findings into a prospectively useful clinical tool.
UR - http://www.scopus.com/inward/record.url?scp=85068454627&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85068454627&partnerID=8YFLogxK
U2 - 10.1016/j.nicl.2019.101908
DO - 10.1016/j.nicl.2019.101908
M3 - Article
C2 - 31491812
AN - SCOPUS:85068454627
SN - 2213-1582
VL - 23
JO - NeuroImage: Clinical
JF - NeuroImage: Clinical
M1 - 101908
ER -