3. Repeated head injury
It follows that if a sudden and severe head injury has the potential to cause alexia in the long term, then repeated but less severe head injuries built up over a long time could have the same effect, and there is science to back this up.
The outcome of multiple negligible and minor head injuries over a prolonged period of time, for decades even, has not yet been well studied and is therefore not that well understood yet.
The data assessing the impact of these repetitive head injuries on short- and long-term neurologic performance has been focused on the sports of boxing and soccer, with American football taken into consideration as well.
Many studies of professional boxers found that repeated brain injury can lead to chronic brain problems down the road, with alexia being one of those along with things like dementia and Alzheimer’s disease. Much more research is needed in this area though.