Hi.
I am truly sorry to learn of your brother-in-laws' condition. I do hope his condition would show some progress soon.
Brainstem strokes can have variable presentations and the prognosis would depend on the severity of brain injury.
It would appear that he suffered significant injury and the prognosis may not be favorable.
You should talk to his doctor's about this.
Good luck.
I'm so sorry...I don't know what to say, except my thoughts are with you right now and HANG IN THERE!