Neurophysiological Study of Traumatic Brain Injury: To Slice or Not to Slice

One of the most critical neuropathological features of traumatic brain injury (TBI) is axotomy [1-5]. Even in mild (m) TBI, diffuse axotomy is easily and consistently observed as axons that end in swellings and dislocation from the distal part of the axon [6-8]. Integrity of axons can be measured in the clinical population with diffusion tensor imaging (DTI) [9-12]. Patient outcome has been correlated with DTI results, [13-16] although subacute imaging may be most effective in this regard [17,18]. Correlations may also be stronger for severe and moderate as opposed to mild injuries [19]. DTI results have also been shown to correlate with the degree of diffuse axonal injury (DAI) as measured with amyloid precursor protein (APP) staining that accumulates in the axonal swelling [20,21]. Treatment assessments have typically been focused on reduction of this axonal injury [22-29], although it has also been recognized that some measures of DAI improve over time while cognitive dysfunction persists [30].