AUTHOR=Slater Jeremy D., Khan Sheraz , Li Zhimin , Castillo Eduardo TITLE=Characterization of Interictal Epileptiform Discharges with Time-Resolved Cortical Current Maps Using the Helmholtz–Hodge Decomposition JOURNAL=Frontiers in Neurology VOLUME=3 YEAR=2012 URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2012.00138 DOI=10.3389/fneur.2012.00138 ISSN=1664-2295 ABSTRACT=
Source estimates performed using a single equivalent current dipole (ECD) model for interictal epileptiform discharges (IEDs) which appear unifocal have proven highly accurate in neocortical epilepsies, falling within millimeters of that demonstrated by electrocorticography. Despite this success, the single ECD solution is limited, best describing sources which are temporally stable. Adapted from the field of optics, optical flow analysis of distributed source models of MEG or EEG data has been proposed as a means to estimate the current motion field of cortical activity, or “cortical flow.” The motion field so defined can be used to identify dynamic features of interest such as patterns of directional flow, current sources, and sinks. The Helmholtz–Hodge Decomposition (HHD) is a technique frequently applied in fluid dynamics to separate a flow pattern into three components: (1) a non-rotational scalar potential