Traumatic brain injury "ages" your brain

As if having a traumatic brain injury (TBI) is not bad enough, recent clinical research suggests it "ages" your brain relative to you true chronologic age. A new study by Cole et al. Annals of Neurology found that TBI-induced brain aging not only causes your brain to exhibit anatomical and functional defects associated with an aging brain, but that the effects are more pronounced the farther out you go from time of injury. In other words, this "aging" process seems to accelerate as one with TBI gets older. 

As quoted from the study's abstract:
"TBI brains were estimated to be 'older,' with a mean predicted age difference (PAD) between chronological and estimated brain age of 4.66 years (±10.8) for GM (gray matter) and 5.97 years (±11.22) for WM (white matter = myelinated axon tracts).

What processes were defined as similar to those observed in the aging brain?

Animal research has implicated a number of biological and pathological processes that affect tissue damage at the time of injury, and progressing even after the initial mechanical tissue damage. Multiple mechanisms such as chronic neuroinflammation, degeneration of damaged axons, and accumulation of pathological tau and amyloid-β proteins often associated with neurodegenerative disease like Alzheimer's disease have been reported. Ultimately, these events cause changes in cell structure and function, cell death, and brain atrophy. These processes often occur simultaneously, while others continue chronically while others subside. Is this really a case of the brain "aging" faster than the body that contains it? It is hard to say. It is also hard to say how true aging that coincides with the progressions of neuropathology interact or influence these processes. Nevertheless, this study yields interesting clinical insights into human responses and outcomes that have long been studied in animal models. It also poses questions to ponder concerning the connections between trauma-induced neurodegeneration, and age-induced or gene-induced neurodegeneration. An interest step in clinical neurodegenerative research, but much more research is needed to fully flesh out answers to questions these results present.


JH Cole PhD*, R Leech PhD, DJ Sharp PhD and for the Alzheimer's Disease Neuroimaging Initiative. (2015) Prediction of brain age suggests accelerated atrophy after traumatic brain injury. Annals of Neurology 77(4): 571-581.