Cerebrovascular injury caused by a high strain rate insult in the thorax

Abstract : Primary blast-induced traumatic brain injury (TBI) has increased in documented incidence and public prominence in recent conflicts. Evidence for a thoracic mechanism of blast-induced TBI was recently reviewed and, while the totality is compelling, data from experiments isolating this mechanism is sparse. Notably, one recent study showed pericapillar haemorrhage in brain tissue from victims of single, fatal gunshot wounds to the chest. Here, qualitative results are reported for a small field study that isolated a thoracic mechanism for TBI caused by a high strain rate insult in white-tailed deer (Odocoileus virginianus, mass 49-80 kg) in a natural environment. In each of three cases, petechiae were present on the surface of the frontal, occipital and/or left parietal lobes, along with capillary damage in the choroid plexus. The location of the projectile impact to the thorax seemed to affect the degree of damage. This may be due to the proximity to the great vessels. The data reported here provides direct evidence of a thoracic mechanism resulting in gross injury to the cerebral vasculature.