Vascular damage: a persisting pathology common to Alzheimer's disease and traumatic brain injury.

Alzheimer's disease (AD) and traumatic brain injury (TBI) are both significant clinical problems characterized by debilitating symptoms with limited available treatments. Interestingly, both neurological diseases are characterized by neurovascular damage. This impaired brain vasculature correlates with the onset of dementia, a symptom associated with hippocampal degeneration seen in both diseases. We posit that vascular damage is a major pathological link between TBI and AD, in that TBI victims are predisposed to AD symptoms due to altered brain vasculature; vice versa, the progression of AD pathology may be accelerated by TBI especially when the brain insult worsens hippocampal degeneration. Our hypothesis is supported by recent data reporting expedited AD pathology in presymptomatic transgenic AD mice subjected to TBI. If our hypothesis is correct, treatments targeted at repairing the vasculature may prove effective at treating both diseases and preventing the evolution of AD symptoms in TBI victims.