Electroencephalography-correlated functional MR imaging studies of epileptic activity

EEG-fMRI is capable of providing novel localizing information in a substantial proportion of patients with frequent epileptiform discharges, even at 1.5T, suggesting a potential clinical role. Increasing availability of equipment capable of providing good-quality intra-MR imaging EEG with relative ease should ensure a more widespread application of the technique in neurology and neuroscience. Early findings in epilepsy have raised a number of interesting issues related to the localization of the activations and the time course of the event-related response that require further investigation. These investigations will benefit from substantial increases in sensitivity resulting from recent and forthcoming technical developments. Validation of the findings will require comparison with invasive and postsurgical findings and further correlations with other measures of brain activity,which should also lead to an improved understanding of the underlying phenomena. To facilitate comparison of findings, improved reporting standards are needed-namely, illustration of activation maps using the glass-brain-more consistent threshold selection,and the listing of all activation clusters, including their volumes, maximum (or minimum) z scores, and peak signal change.