Blunt basal head trauma: aspects of unconsciousness.

Two cases of street violence directed to the skull base level and transverse to the cervical axis are described. No skeletal damage. The violence resulted in the so-called "traumatic subarachnoid haemorrhage", an often used, unspecified forensic "diagnosis"; it was here revealed to be due to rupture of the wall of the posterior inferior cerebellar artery (p.i.c.a). However, this was only one of the possible explanations for the acute symptoms of unconsciousness (concussion) and almost immediate death. The careful examination of these two cases and of a series of control cases revealed that at the trauma, stress and strain may have occurred to arterial branches serving as feeding perforant vessels to the medulla oblongata; in these cases they were coursing directly from the p.i.c.a. region.--The type of direct impact has often been regarded as mild! However, its location suboccipitally as in these cases can become dangerous. The resulting direct or indirect deficit of brain stem functions are discussed in these cases as well as "concussion-related symptoms" resulting after other types of head and neck injury.