Good point. I did not know that he had surgery in the frontal area. That explains a lot.
Ideally, the aneurysm is repaired without disturbance to the cereberal tissue. But, it depends...
He’s always been a loose cannon, verbally. In debates, as with Paul Ryan, it can work well for him, because he’s unrestrained. But his memory used to be intact.
Now, his memory is obviously shot, and he has no impulse control. Demented rather than charming.