Orthostatic Intolerance as a neurological disorder

Just pondering something here. I have orthostatic intolerance. A cardiologist explained to me that it's caused by autonomic insufficiency in response to postural change. The result being the my body does not adequately adjust my blood pressure when I'm vertical. So if the cause of all this is a problem with my autonomic nervous system, wouldn't that mean this is (at least in part) a neurological disorder?

 

By definition, your doctor's explanation seems to presume an autonomic disorder as causal ("caused by autonomic deficiency"). However, there are competing theories regarding the cause of OI and perhaps distinct groups of patients with differing causes. The first alternative explanation to come to mind is low fluid volume. Fluid loading and increasing fluid intake are primarily efforts to increase volume. Vascular tone may also play a role. Fluid volume may be neurological but is not primarily autonomic and vascular tone may be autonomic but not necessarily so.

 

I haven't had OI since I got my levels of B12/folate up. My (other) neurological symptoms cleared in this same time frame.