Myelin degradation, axonal changes and expression trajectories of glial cells stimulated by rapid head insult in humans to estimate approximate time elapsed since trauma

Abstract

Background Post severe traumatic brain injury (sTBI), axonal alterations lead to myelin loss and its degeneration. In the recovery phase, numerous intermingled biochemical pathways involving complex inflammatory reactions cloud the understanding of this yet undiscerned process that also varies with agonal period. In cases with dubious histories, approximating the survival time can be challenging, and expression levels of characteristic markers may aid forensic experts in the same. Methods This exploratory study recruited 100 samples—68 sTBI, 22 non-TBI and 10 age- and sex-matched control samples. Male:female ratio was 87:13. Histochemical staining using H&E was used to characterize myelination pattern, and IHC of GFAP and CD-68 were performed to assess astroglial and microglial reactions with respect to survival time in specific sites. Result Among sTBI, non-TBI and control recruits, sTBI patients depicted significant myelination abnormalities, astroglial proliferation and microglial reaction and varying with survival time. Non-TBI and control samples depicted nearly similar profiles. Conclusion In order to untangle the complex mesh of biochemical responses, nuanced research on individual factors (both pre- and post mortem) with regard to specific site and survival time are warranted. Standardizing experimental data and converting it into empirical data shall aid forensic experts in suggesting approximate agonal period.