I think what C4E is writing is very important, and that is if you isolate many of the peculiar patterns and then try to correlate with what is known about the brain, there may be a way to figure out what part or parts of the brain are affected, which may in turn offer clues as to what might have gone wrong.
I am like you C4E, I was away from my husband when this started so I did not experience the "overnight" change many people have, although in retrospect I can see clues that something was going on leading up to it. But it seems that in many of these stories there is a time when the afflicted person knows something might be wrong, and when a line is crossed.
I met a neurologist who told me that minor brain bleeds can have this affect as the blood that pools can take three years at least to drain. She told me that it is possible someone could have a self healed minor aneurism or stroke that could result in this.
Another marker seems to be rapid aging and changed appearance to the eyes. What is causing this plus the other symptoms we so uniformly observe?
I agree it is important for any LBS to understand this as a physical change and not an emotional/circumstial one. If for instance you see this as the brain not being able to distinguish between fantasy and reality, regulate emotions, understand consequence, feel empathy -- and not someone just "acting out" -- it is easier to manage responses that don't exacerbate the condition, especially in a state of shock and trauma.
C4E thank you again for reinvigorating this discussion and inspiring me to make the effort to reach out to researchers and neurologists.