When I said "literature" I meant the medical case histories referred to. I forgot that other people, not having had my crash course in medical terminology, would read that as the sort of literature that gets studied in English classes.

But of course you are right that there are a number of people changed as a result of illness in JA's other novels. I think a good observer of humanity would notice these changes, even without the understanding of current medicine. JA may have seen a person in real life get a head injury and become very nervy afterwards, and applied the same change to Louisa.