What Causes Dizziness And Metallic Taste In The Mouth?

My signifigant other is having some strange symptoms. Today he woke up feeling a little off. He said he fealt that his equilibrium was off and he was having a hard time walking due to the dizzy spells he was having. He has a metallic taste in his mouth and hes having headaches, body aches, fatigue, restlessness, sleeplessness, anxiety, high amounts of stress, slowed memory, etc. i know that he, recently, was cut down and or off of his benzodiazapine (klonopin) and was given another drug that seemed to make him more agitated. i realize how hard it can be to go thru benzo withdrawal and alot of these symptoms can be confused with or brought on by the withdrawal itself. the metalic taste came shortly after going to the hospital for testing on his brain. He had an EKG, blood draw, and a MRI. The reason he was having the testing done, I believe, is because he was falling asleep at the wheel, having serious migrane headaches almost daily, severe numbness in hands and feet, pain in his arches of his feet...mostly his left foot , he has never had carpal tunnel surgery. He is normally sharp as a whip and can retain information, numbers, names, mathmatics etc. very easily. Today he is struggling to remember the smallest of things and that, of course, gets him more stressed which, in turn, can cause more anxiety. He is waiting to get the results of his tests and in the meantime he is having more issues daily. What can be causing this and what can we do? He says he feels like hes been drugged. Thank you, Carol