Neurological assessment relies on two main categories of technology: (1) tomographic reconstruction of structure and hemodynamic/metabolic processes; and (2) recordings of electromagnetic fields. These technologies have complementary sensitivities. Hemodynamic assessment of brain activity using functional magnetic resonance imaging (fMRI) is temporally limited by the latency of the hemodynamic response, about 1 second, but can provide millimeter spatial sampling. Electroencephalography (EEG) and magnetoencephalography (MEG) provide temporal resolution of less than 1 millisecond, but their spatial resolution for multiple sources is ambiguous and limited. The applicants have developed a method that combines MEG with fMRI and structural MRI to obtain high-resolution spatiotemporal maps of dynamic human brain activity. We propose here to extend this method to include EEG, a less expensive, more widely available and clinically validated alternative to MEG. The integrated method will be refined and tested in simulation studies as well as by direct comparison with intracranial recordings in humans. Thus, the ultimate goal of the current research is to validate and extend an effective method that unites the dominant technologies used for neurological diagnosis. It is anticipated that this method will have applications in the localization of epileptic foci for presurgical planning and the sparing of cortex performing essential functions in elective neurosurgery.
Neuropsychiatric diagnosis and scientific software.
