4. Tumor
It is possible that a brain tumor could also be a potential cause for alexia, especially when that tumor is found in the brain, and more specifically in the part of the brain that affects how a person reads the written word.
Tumors are obviously incredibly scary things for people to experience, and often, it is not the long term implications of developing a tumor that worries someone, but the short term threat to life and potential diagnoses that the person may receive, together with any of the initial treatment options they might have to go through.
When all of the work in terms of shrinking or removing the tumor is said and done though, there can be lingering remnants of damage caused by its initial growth.
One of these lingering remnants could be the development of alexia at some point down the line, and it is a safe bet to assume that a brain tumor will have had more than a minor role in the development of this condition.