Electroencephalography/functional MRI in human epilepsy: what it currently can and cannot do

Area of Science:

• Neuroscience
• Medical Imaging
• Epileptology

Background:

• Simultaneous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) is increasingly used for studying brain function and disorders.
• Epilepsy research, in particular, benefits from this combined neuroimaging technique.

Purpose of the Study:

• To summarize recent epilepsy-related studies utilizing EEG/fMRI.
• To critically evaluate the clinical and scientific value of EEG/fMRI in epilepsy.

Main Methods:

• Review of recent epilepsy-related studies employing simultaneous EEG/fMRI.
• Appraisal of the diagnostic and research utility of EEG/fMRI data.

Main Results:

• EEG/fMRI provides valuable information for epilepsy presurgical evaluation, identifying interictal and ictal patterns.
• Current limitations include a lack of extensive validation studies, variable patient data informativeness, and non-localized hemodynamic patterns.
• EEG/fMRI data often reveal distributed brain networks, aiding in the conceptualization of epileptogenic networks in various epilepsy syndromes.

Conclusions:

• Clinical applications of EEG/fMRI include guiding further investigations like advanced structural imaging or planning intracranial electrophysiological studies by hypothesizing epileptic focus locations.
• Ongoing validation studies are crucial for establishing the clinical appropriateness of these applications.
• EEG/fMRI advances the understanding of dynamic cerebral processes in health and disease by assessing epileptogenic networks and brain state changes.