Question

What are the macroscopic features (neuropathology) of chronic TBI? How is the structure of the brain affected?

Answer 1

TBI stands for Traumatic Brain Injury. TBI damages axons and elicits both regenerative and degenerative tissue responses in the brain and in whom repeated concussions may initiate a long-term neurodegenerative process called dementia pugilistica or chronic traumatic encephalopathy. TBI happens because of improper metabolism and aggregation of tau, β- amyloid, and TDP-43. There are various types of TBI. Acute brain injury comprises mild TBI or concussion including its short-term sequelae and catastrophic brain injury that may lead to death, most commonly due to subdural hematoma. Chronic brain injury, called dementia pugilistica or CTE, is a neurodegenerative disorder due to repeated head trauma. Researchers argue that metabolic dysfunction, including reduced mitochondrial energy status in the brain with increased metabolic demands but decreased energy stores with a low ATP/DTP ratio and increased lactate/pyruvate ratio, may play a role in TBI. Mild trauma stimulates a type of sodium channelopathy on axons, which, in turn, intensifies patho-physiological responses to succeeding minor injuries. This leads to the damage of axon terminals. Therefore, it may be concluded that the brain structure changes because of these neurochemical changes that take place after the TBI.