How To Treat Multiple Blood Clots In Brain?

My 84 year old dad has Parkinson s which was diagnosed about 10years ago. He stopped taking his medication for Parkinson since it did not improve his hand tremors.About a month ago he suddenly experience muscle weakness in his lower and upper extremities. He went back to see a neurologist and resumed taking his Parkinson med. which seem to help. He was also sent for a brain MRI which showed multiple blood clots. He s been taking xarelto for atrial fib. Does he need surgery for the blood clots in his brain?