====== Traumatic subarachnoid hemorrhage pathology ======

[[Traumatic subarachnoid hemorrhage]] is most commonly seen in the cerebral [[sulci]] than in the [[Sylvian fissure]] and [[basal cistern]]s
((Wu Z, Li S, Lei J et-al. Evaluation of traumatic subarachnoid hemorrhage using susceptibility-weighted imaging. AJNR Am J Neuroradiol. 2010;31 (7): 1302-10. doi:10.3174/ajnr.A2022))

When in the [[basal cistern]]s, it has an affinity for the [[quadrigeminal cistern]] and [[ambient cistern]]
((Yee-Chiung Gan, Munchi Soli Choksey, Rebleed in traumatic subarachnoid haemorrhage, Injury Extra, Volume 37, Issue 12, December 2006, Pages 484-486, ISSN 1572-3461, http://dx.doi.org/10.1016/j.injury.2006.07.045.)),
tSAH is also commonly seen adjacent to [[skull fracture]]s and [[cerebral contusion]]s
((J. van Gijn, G. J. E. Rinkel. Subarachnoid haemorrhage: diagnosis, causes and management. Brain Feb 2001, 124 (2) 249-278; DOI: 10.1093/brain/124.2.249))

The exact mechanism of tSAH remains uncertain although it is clear that a number of etiologies exist and these will determine, at least to a degree, the distribution of blood. Causes of tSAH include
((Modi NJ, Agrawal M, Sinha VD. Post-traumatic subarachnoid hemorrhage: A review. Neurology India. 64 Suppl: S8-S13.)):

direct extravasation of blood from an adjacent cerebral contusion

arterial dissection

direct damage to small veins or arteries

sudden increase in intravascular pressures leading to rupture