What is axonal injury?
Overview. Diffuse axonal injury (DAI) is a form of traumatic brain injury. It happens when the brain rapidly shifts inside the skull as an injury is occurring. The long connecting fibers in the brain called axons are sheared as the brain rapidly accelerates and decelerates inside the hard bone of the skull.
What causes axonal injury?
The most common etiology of diffuse axonal injury involves high-speed motor vehicle accidents. [2] The most common mechanism involves an accelerating and decelerating motion that leads to shearing forces to the white matter tracts of the brain.
Can axons be repaired?
After peripheral nerve injury, axons readily regenerate. This active process results in fragmentation and disintegration of the axon. Debris is removed by glial cells, predominantly macrophages. Proximal axons can then regenerate and re-innervate their targets, allowing recovery of function.
What happens when axons are damaged?
If an axon is damaged along its way to another cell, the damaged part of the axon will die (Figure 1, right), while the neuron itself may survive with a stump for an arm. The problem is neurons in the central nervous system have a hard time regrowing axons from stumps.
Can you live without axons?
– Spinal cord injury can disrupt communication between the brain and muscles when neurons lose their connection to axons located below the site of injury. These neurons may still live, but they lose their ability to communicate. One method of cell death results from the release of excess glutamate.
Will an MRI show a TBI?
About 80 percent of TBIs cannot be seen on an MRI or CT scan. The only other way to discover a TBI used to be neuropsychological or psychological testing – a fancy way of saying doctors ask patients questions or give them tasks to complete.