Even if his condition was brought about by a hex, what you are describing sounds like brain damage. Even if you undo the hex, the damage is done and needs to be addressed immediately by medical professionals.
Let's take this for example, if person A curses person B and person B falls down the stairs and breaks his leg or suffers a heart attack, you cannot break the curse to cure the damage done. Person b still needs to be healed by physical medicine. Undoing the curse will prevent future occurrences but will but correct ones that have already happened.
Another example, if a hex is placed and your house burns down, nothing is going to bring back that house.
Bottom line, this guy needs to be seen by a doctor.
You can undo whatever hexes may be on him while he's hospitalized.