The increased risk of developing Alzheimer's Disease after TBI has been know for a long time. A problem with this concept is simple. Since the age related decline due to TBI is very similar to the decline due to AD, could there be an overlap where subjects with a TBI history decline due to their TBI history and not due to AD ? It is very difficult to precisely diagnose AD except at autopsy.

My father die from dementia. The simple diagnosis was AD. The progression was not the same as a normal AD progression. I believe he died from ischemic dementia due to his 40 year battle with Central Sleep Apnea. The doctors used the easy diagnosis of Alzheimer's Disease.

Until more is know about the causes of AD, we will just have to do what we can to maintain good brain nutrition and stimulation.