Diffuse axonal injury (DAI) describes damage to the axon of a neuron. Axons are covered in white, fatty matter that helps to quickly relay messages back and forth, and the major region of the brain that is dense with this white matter is called the corpus callosum. As such, the corpus callosum is the most vulnerable to damage from DAI.
Recently, a team of UCLA researchers studied the long-term effects of injury to the corpus callosum in pediatric brain injury patients, as well as the correlation of injury to cognitive functioning. They found that there were structural and metabolic differences in the corpus callosum between the acute and chronic stages of injury. These metabolic changes could be related to the energy used during neural repair, or from changes due to permanent cell death. Furthermore, metabolic dysfunction and structural damage seen in the corpus callosum after DAI was associated with declines in cognitive functioning.
The preliminary results of this study contribute to the understanding of how metabolic and structural changes might develop long-term in cases of pediatric traumatic brain injury. Although future studies may pinpoint the exact time course of these changes, it is important to acknowledge that degeneration of the corpus callosum may continue long after the initial injury.
Babikian T, Marion SD, Copeland S, Alger JR, et al. Metabolic levels in the corpus callosum and their structural and behavioral correlates after moderate to severe pediatric TBI. Journal of Neurotrauma. (March 2010).