Get a 2nd and even 3rd opinion ASAP! You do not want to mess around with something like that especially when stroke obviously runs in the family! And if that is how he said it - "A hole in the brain"... and did not elaborate any further, something is wrong with that man.
Also, your GUT is telling you something isn't right, so please make those appt's right away!
Best wishes to you and your sis