Non-traumatic brain injuries, also called acquired brain injuries, encompass all forms of brain damage that result from factors other than external blunt force. This category includes stroke, aneurysm, oxygen deprivation, including hypoxia and anoxia, toxin exposure such as lead, brain tumors, viruses, and encephalitis. Non-traumatic brain injuries can spread from one brain region to another, while traumatic brain injuries cannot. Traumatic and acquired brain injuries produce similar symptoms; treatment may be similar but target different underlying problems.