AXONAL INJURY - A DIAGNOSTIC-TOOL IN FORENSIC NEUROPATHOLOGY - A REVIEW

We used beta-amyloid precursor protein (beta-APP) to investigate our o wn forensic neuropathological case material (n=252) in light of the cu rrent literature on the phenomenon ''axonal injury'' (AI) to determine the incidence, specificity and biomechanical significance of AI and i ts significance for determining vitality and survival time. The case m aterial consisted of cases of fatal nonmissile closed-head injury (n=1 19), gunshot injury (n=30), fatal cerebral ischemia/hypoxia (n=51), br ain death caused by mechanical trauma (n=14) or nonmechanical injury ( n=18), and acute hemorrhagic shock (n=20). AI was observed in 65% to 1 00% of cases of closed-head injury, fatal cerebral ischemia/hypoxia, a nd brain death with a survival time of more than 3 h; AI could not be detected in the cases of acute hemorrhagic shock. A statistically sign ificant difference between traumatically and nontraumatically induced (nondisruptive) AI was not found. There was no statistical evidence of a correlation between AI and the different types of external force, s ince AI could be demonstrated after both acceleration/deceleration inj uries and traumatic impact. Therefore, biomechanical inferences for re construction purposes are not possible. On the other hand, beta-APP wa s found to be a definite marker of vitality. In our material, cases wi th a posttraumatic interval of under 180 min did not express beta-APP. Moreover, the literature shows that the posttraumatic interval can be determined by other methods for demonstration of AI such as by ubiqui tin immunostaining (360 min), silver staining (15-18 h), hematoxylin a nd eosin staining (about 24 h), or by demonstration of a microglial re action (about 4 to 10 days) or of a few remaining isolated bulbs, with out accompanying fibers, which can be detected after a survival time o f up to 17 months. (C) 1998 Elsevier Science Ireland Ltd. All rights r eserved.