RESUMEN
Traumatic basal subarachnoid haemorrhage (TBSAH) represents only 1.8% of all subarachnoid haemorrhage cases diagnosed during autopsy. This report presents such a case from the current practice of the authors. Sixteen-year-old boy was beaten by the aggressors. Suddenly he lost his consciousness and fall after he received a single blow in the neck. He was resuscitated immediately, but died at the scene. During the external examination we did not find any significant external injuries. Autopsy revealed large contusion of right sternocleidomastoid muscle. In the cranial cavity we found extensive subarachnoid haemorrhage, located mainly on brain basis, in the posterior cranial fossa and covering the subtentorial structures. During the preparation of blood vessels we noticed a slight change of morphology suggesting damaged vessel or aneurysm, or vascular malformation located in the basilar artery bifurcation, which was taken to detailed microscopic evaluation using the special stainings. Histological examination showed vital interruption of the basilar artery wall with massive haemorrhage, without the presence of general microscopic pathology. From the medico-legal viewpoint, to determine traumatic background of haemorrhage it is necessary to find the coexistence of the following circumstances: a sustained trauma, post-mortem findings consistent with a time of injury, the presence of temporal relationship between injury and death, and morphological vital injury of the brain vessel, as well as the absence of prior vascular malformations. For this purpose Verhoeff-van Gieson's, Masson's, Turnbull's and Gomori' histological stainings may be successfully used.