Magnetoencephalography, Diffusion Tensor Imaging and Transcranial Magnetic Stimulation in Managing Cognitive Behavioral Changes after Intracranial Vascular Surgery

Abstract

Some frontal and temporal lobe areas are known to be part of the limbic system. The prefrontal, orbitofrontal and basal forebrain nuclei are examples of frontal lobe anatomical structures that have direct connections with the hippocampus, amygdala and basal ganglia component of the limbic system. The cognitive functions that are associated with these areas are memory, behavior and attention. Surgical clipping of a ruptured intracranial anterior circulation aneurysm would require some manipulation or retraction force applied to these regions and with concurrent presence of cisternal hemorrhages, brain edema and swelling, neurocognitive impairment is likely. By using state of the art technique in magnetoencephalography (MEG), diffusion tensor imaging (DTI) and standard neuropsychological assessment tools, gross abnormalities in brainwave morphology, contour of white matter fibers and neuropsychological scores were detected. Appealingly, these abnormalities were also used to rehabilitate the cognitively impaired individuals by using neuro-navigation guided transcranial magnetic stimulation (TMS) and utilizing stimulatory (fast) and inhibitory (slow) mode of the repetitive stimulation.