What Causes Dizziness,numbness In Left Arm And Brain Fog?

Hi, for years my husband has had headaches, dizziness, his face is droopy down one side, he has mood swings and anger problems. He feels a swelling on the back of his head that comes and goes, sometimes has a numb left arm and tightness across chest and sees flashing lights, hears voices and stomach problems and has sometimes has brain fog. He has been for various tests and has been told he has Irritable Bowel Syndrome and Fybomyalgia. Could it be something else.