Traumatic aneurysms of the pericallosal arteries.

Of a total of 912 operated intracranial aneurysms only three were classified as traumatic (0.3%). They were found in children after severe head trauma and were all located on the pericallosal artery or its branches and not at bifurcations. Shearing forces between the falx, the arteries and the brain at the time of injury are held responsible for the development of these aneurysms. Unlike these traumatic aneurysms, 29 "spontaneous" pericallosal aneurysms (3.2%) in adults were located at the bifurcations of the artery. As significantly fewer reports of traumatic aneurysms have been published during the last decade than before 1976, it is suggested that some might have been overlooked as a consequence of CT replacing cerebral angiography in the neuroradiological evaluation of severe head injury. This possibility should be kept in mind, especially when dealing with children after head injury and when CT scans indicate brain damage around the falx. The possibility of overlooking traumatic pericallosal aneurysms is described by other authors and discussed further in this paper.