Progress of Research on Diffuse Axonal Injury after Traumatic Brain Injury

Abstract

The current work reviews the concept, pathological mechanism, and process of diagnosing of DAI. The pathological mechanism underlying DAI is complicated, including axonal breakage caused by axonal retraction balls, discontinued protein transport along the axonal axis, calcium influx, and calpain-mediated hydrolysis of structural protein, degradation of axonal cytoskeleton network, the changes of transport proteins such as amyloid precursor protein, and changes of glia cells. Based on the above pathological mechanism, the diagnosis of DAI is usually made using methods such as CT, traditional and new MRI, biochemical markers, and neuropsychological assessment. This review provides a basis in literature for further investigation and discusses the pathological mechanism. It may also facilitate improvement of the accuracy of diagnosis for DAI, which may come to play a critical role in breaking through the bottleneck of the clinical treatment of DAI and improving the survival and quality of life of patients through clear understanding of pathological mechanisms and accurate diagnosis.

Electro-mechanical response of a 3D nerve bundle model to mechanical loads leading to axonal injury

“…These two loading conditions are cases of clinical interest. A constant pressure on an axon is representative of injuries [1], [3] and plaques in demyelinating diseases, acting as conduction block for action potentials of neighbouring 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 P e e r R e v i e w O n l y 11 axons inhibiting the myelinisation process. Instead, elongation tests might explain the relatively long time period needed for spontaneous membrane repair after fast strain [13].…”

“…In this section, the fully coupled electro-mechanical model of Fig. 2 is applied to investigate different mechanical loading conditions directly using equations (1)(2)(3)(4), instead of as a simulated voltage-shift. Fig.…”

“…Although DAI is classified as an independent category of disease from TBI, the pathological mechanism of DAI is very complex and, currently, there are no diagnostic criteria [3]. A better understanding of P e e r R e v i e w O n l y 2 mechanically-induced electrophysiological impairments and damage associated with morphological changes of neural cells is urgently needed to improve diagnosis, clinical treatments and prognosis [3], [7].…”

Effects of nerve bundle geometry on neurotrauma evaluation

“…Head injuries may result in traumatic brain injury (TBI), which is categorized as mild, moderate, and severe based on clinical symptoms and postmortem histology . The rapid acceleration‐deceleration of the head during TBI generates a diffusive form of microscale damage, such as diffuse axonal injury (DAI) and microvascular damage . However, microscale damage is difficult to detect with the current medical imaging technology due to hemorrhages, hematomas, and tissue lesions of the neighboring injured area .…”

“…The use of a 3D geometry with plastic material properties allows for the simulation and evaluation of strain and voltage distributions before and after the induced damage. The inclusion of 3D mechanically induced electrophysiological impairments is needed to enhance the understanding of electromechanical changes in neurotrauma evaluation and improve diagnosis, clinical treatment, and prognosis . This approach might prove crucial to study and understand the mechanics at play in neurophysiology, as observed experimentally in damaged nerve membranes of clinical cases such as multiple sclerosis …”