  The Electrocardiography Brain Perfusion index (EBPi) is a novel
electrocardiography (ECG)-based metric that may function as a proxy for
cerebral blood flow (CBF). We investigated the spatio-temporal correlation
between EBPi and epileptic seizure events. EBPi was computed retrospectively
from clinical EEG and ECG data captured previously from 30 epilepsy patients
during seizures. Significant EBPi changes were compared temporally with
clinically defined ground-truth seizure onset and offset times. We also
assessed the spatial correlation between EBPi metrics and clinically defined
ground-truth seizure locations. A significant increase in EBPi was detected
10.5 s [-6, 53] (median [95% confidence interval (CI)]) after ground-truth
seizure onset, and a significant decrease in EBPi was detected 5 s [-42, 74]
(median [95% CI]) after ground-truth seizure offset. EBPi demonstrated a
positive predictive value of 61.5% [33.3, 75] (median [95% CI]) and a
sensitivity of 57.1% [38.5, 66.7] (median [95% CI]) for the detection of ground
truth seizure locations. EBPi signals exhibited a temporal sensitivity to
seizure events and in some cases were correlated spatially to the seizure
location. Therefore, EBPi, which has been linked to CBF, appears to contain
spatio-temporal information related to seizure activity and might have useful
application in augmenting EEG data captured during seizures.
