http://www.nucleushealth.com/ - This 3D medical animation shows and explains the mechanism for mild traumatic brain injury, which includes concussion injuries. Two types of coup-contrecoup injury are shown: low-speed coup-countrecoup injury, and high-speed coup-contrecoup injury. The high-speed coup-contrecoup injury creates apparent contusions. The low-speed coup-contrecoup injury has damage from shifting layers within the brain at the microscopic level. This animation shows axonal-shearing or how axons rip away from the cell bodies of neurons during coup-contrecoup, and the degenerative damage that occurs later.