Electroencephalography-correlated functional MR imaging studies of epileptic activity

This article focuses on the use of combined electroencephalography and functional MR imaging (EEG-fMRI) as a tool to investigate the relationship between epileptiform discharges and hemodynamic changes. Essentially a functional MR imaging technique, EEG-fMRI can provide whole-brain maps of those changes, and hence has the potential to give a new form of localizing information on the generators of epileptiform discharges. The author briefly reviews the problem of localization in epilepsy and, in particular, the roles of EEG and functional MR imaging, and then discusses the motivations for combined EEG and functional MR imaging experiments, the possible ways in which the data can be acquired, and the associated technical requirements. This is followed by a presentation of the analysis methods used and a discussion of the applications of EEG-fMRI in epilepsy. An overview and discussion of the main findings and ideas for future research is also provided.