Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Multiple System Atrophy with Orthostatic Hypotension ?
    ### Response:
    Multiple system atrophy with orthostatic hypotension is the current classification for a neurological disorder that was once called Shy-Drager syndrome. A progressive disorder of the central and autonomic nervous systems, it is characterized by orthostatic hypotension (an excessive drop in blood pressure when standing up) which causes dizziness or fainting.
    