But this is not a new story. Indeed, the observation that head trauma could cause dementia was first made in the 1920s when the term "dementia pugilistica" was coined to describe the occurrence of dementia in boxers who suffered repeated head trauma. In the modern era, head trauma (particularly with loss of consciousness) was recognized as a risk factor for Alzheimer's disease more than 25 years ago.
Other studies have shown that head trauma is associated with increased amyloid production and neurofibrillary tangles, the classic pathological hallmarks of Alzheimer's disease, providing a scientific basis for the relationship. This makes sense; beta-amyloid is probably produced in the brain in response to injury, and the "tangles" are markers of neuronal injury.