Of course, to a Top Neurologist it would be easy. Duh. However, the surgery required could kill her...
There were going to kill her anyway.
No one should be put to death by starvation based on a test done 9 years ago, when better tests are available now.
It is clear as day they don't want to know her current mental state (and indeed forbid any new tests), this was outcome driven from the beginning.