Multi-modality Localization of Eloquent Brain Function

Accurate identification of areas of eloquent brain function is vital to surgical decision making and to preservation of independence as patients with brain tumors who are higher functioning have better survival outcomes. Eloquent brain is defined as a region controlling language, motor, or sensory function such that without its proper input, a person would be left with significant neurologic deficits. Imaging technology has evolved to provide multiple non-invasive modalities for pre-operative testing of eloquent brain function. Studies have shown that these non-invasive mapping modalities provide useful information, however, the information provided inconsistently predicts distribution of eloquent function. Direct electrical stimulation (DES) at surgery allows assessment of eloquent function directly from the brain surface (invasive) and is considered the gold standard in brain mapping. Therefore, in order to determine the true clinical applicability of the non-invasive mapping technologies, this study proposes to assess the predictive value of functional MRI (fMRI) and magnetoencephalography (MEG) for sensorimotor and language functions by comparing results to DES and determine whether fMRI or MEG provides the most consistent and accurate information. The rationale for the proposed research is that understanding the reliability of our current technology will allow us to perform safer surgeries and to preserve neurologic function.