Brain imaging has evolved considerably over the last decade or so. Major advances have included the ability to image, not only structurally, but functionally. These advances are being driven by the understanding that the networks of the brain, rather than individual neurons, underlie the brain’s processing capabilities. Diffusion tensor imaging is able to image structural connectivity in the brain, whilst techniques, including fMRI, EEG, MEG, are able to image dynamic functional networks.
Brain injury affects both structural and functional connectivity and can now be visualized with unprecedented ability. One of the findings of recent work with these neuroimaging modalities is the fact that similar white matter structures tend to be damaged across patients. This translates to similar clinical symptoms and deficits across patients. There is evidence that the brain has a small number of “modes,” conferred by its anatomical structure, which may explain the consistency of white matter fiber damage across patients. This talk will discuss the advances in neuroimaging capabilities in the context of important clinical questions in order to explain the clinical syndromes as well as to give a rationale for treatment intervention using the same imaging tools.
One perspective on neuroimaging results can be achieved through the analysis of trauma. Historically, this evaluation was done through the study of contact force, translational acceleration, rotational acceleration, intercranial pressure (ICP), stress, strain, strain energy and rate, as well as a combination of any of these.
Like every other structure, the human brain has its own natural frequency. When an applied load is close to that frequency, high deformation of brain tissue is expected. Therefore, an additional approach to consider in evaluating TBI should include examination of vibration (excitation) of the brain at different frequencies. Preliminary results from finite element (FE) analysis of head impact and blast loading indicates some regions of the brain reach the lower natural frequencies (20~40 Hz) and resonate with higher amplitudes.
Given these findings, the use of neuroimaging and in-depth biomechanical analysis of brain dynamics, can provide for more robust evaluation and treatment of TBI.