my mother is 76 years old and has been healthy- for about two months she has a total loss of energy, double vision in one eye, dizziness, and sick at her stomach a lot of the time. She went to Dr and they found out she had a non cancerous meningioma. They are not going to operate and said that they will monitor for year to year and if it grows they will do surgery. My question is this- what are the possible causes of her sickness now?