Suggest Treatment For Fluid Collection In Head After Removing Brain Tumor

My husband had a brain tumor removed in November that was non-cancerous. After the surgery fluid collected at the top of his head where the tumor was removed. After about 6 weeks the fluid moved to the base of his head. He has small episodes that cause blurry vision in his right eye, numbness in his right arm and weakness in his legs. It seems to only last about 3 or 4 minutes and then it goes back to normal. This happens periodically throughout the day. Is this normal after surgery or should we be concerned?