Emma experienced the "one week slide" - in her case it lasted about three days. We have no idea what it was, it could have been a mini relapse, it could be the body reacting to it's new blood flow - we just don't know.
After three days it just disappeared and all the post op improvements returned along with a few more bonus improvements.
We're now a month on and she continues tiny daily incremental improvements. It's only when you take a week by week or month by month snapshot that you realise the extent of the improvements.