A stroke occurs when blood flow to a part of the brain is interrupted. If the blood flow interruption lasts longer than a few seconds, brain cells can die resulting in permanent brain damage or death.
A traumatic brain injury (TBI) can also result in the mechanical destruction of brain cells leading to permanent injury or death. Researchers are now investigating whether TBI is an independent risk factor for stroke. In other words, does the brain damage from TBI make it more likely that a TBI survivor will have a stroke resulting in even more brain damage?
A study in the July 2, 2013 issue of the journal Neurology entitled “Traumatic brain injury may be an independent risk factor for stroke” investigated that link (Volume 81, Number 1, July 2, 2013). The authors found a “robust association” of TBI and stroke. This association continues to increase “even years after the initial injury.” The mechanism responsible for this association is not clearly understood, but it may be due to “vascular dissection, microvascular injury, or coagulation.”
Much more research needs to be done to understand why this linkage exists and whether TBI is truly an independent risk factor for stroke.