AAN 2026 | Autonomic dysfunction in Parkinson’s disease and related disorders: impact and management

Autonomic dysfunction is incredibly common amongst those with Parkinson’s disease and other Parkinsonian disorders. Of course, the prevalence varies by type of disease. It is also sorely underdiagnosed and underreported. And there are many reasons for that. The most important one being that often our patients do not know that they have, even if they do not have symptoms pertaining to autonomic dysfunction, that does not mean that they are not being affected by autonomic dysfunction. A study that was done at the University of Cincinnati a few years ago demonstrated that about 30% of patients with orthostatic hypotension, so when these patients go from a supine position to a standing position, their blood pressure drops, and their heart rate does not increase relative to how much their blood pressure drops. So these have a neurogenic orthostatic hypotension. So patients with orthostatic hypotension should have lightheadedness in the event of getting up. But in those with Parkinson’s disease, about 30% of them may not have any symptoms, but that does not mean that they do not have increased fall risk or worse ability to perform their activities of daily function. So they have the same risk of fall and same risk of worsening activities of daily function as those with lightheadedness. So it is imperative that we screen these patients when they come to our clinic, not just with symptoms, but also by measuring supine and standing vitals.

In MSA, multiple system atrophy, early autonomic dysfunction, not just postural lightheadedness, but also urinary dysfunction. So urinary incontinence, constipation, even erectile dysfunction is quite common and must be questioned, especially in women where there may be a little bit of a hesitation in clinic to ask these questions and gather these pieces of information. In patients with dementia with Lewy bodies and with Parkinson’s disease dementia, these symptoms are quite common. And our work, along with other work, work from other places, has shown that there may be a direct correlation between the severity of autonomic dysfunction and neuropsychiatric burden.

Recently, we also showed that in prodromal Parkinson’s disease, based on the Michael J. Fox Foundation-funded PPMI data, even patients with prodromal Parkinson’s disease, so this is patients who do not have Parkinsonism enough to meet criteria for Parkinson’s disease, so early on in the disease, even in that patient population, you can have autonomic dysfunction that goes largely undetected. And the presence of that autonomic dysfunction, especially cardiovascular autonomic dysfunction, is associated with faster conversion to Parkinson’s disease, worse outcomes overall, and even incident cognitive risk.

So first of all, as I mentioned earlier, I think if we ask, the patients won’t tell, right? These are one of the things that largely go underneath the surface. Most patients now, thankfully, know about a tremor, slowness, stiffness, the motor signs of Parkinson’s. And if they don’t know initially, by the time they get referred to centers who take care of patients with Parkinson’s disease, they’ve already done their homework. They’ve gone through Parkinson’s foundation, Michael J. Fox foundation, et cetera. And they know about the motor features of Parkinson’s, but these questions must be asked. So there are certain scales such as SCOPA amongst others, that can tease out all these different symptoms associated with autonomic dysfunction in Parkinson’s disease. Although it is time-consuming, it is not a bad idea to have a really low threshold for measuring supine and standing after three minutes, blood pressure and heart rate in patients with a concern for autonomic dysfunction, actually everybody with any signs of Parkinsonism.

If my patients have orthostatic hypotension, the first thing I do is go through their medications to see if they are on antihypertensives or any medication that can lower their blood pressure. The second thing I do is speak with the physician that has prescribed them these medications. As our patients are usually older, a number of them have cardiac disease, hypertension, other cardiovascular and cerebrovascular risk factors. So it’s important to speak with the primary care physician or with the cardiologist or nephrologist who has prescribed these medications to see if they can be on a lower dose or ideally get off these medications. The second approach, the second thing is conservative management. So they can increase the amount of water intake, salt intake, the abdominal binders, the compression stockings that can be used in the right patient. You have to tailor all of these based on other comorbidities, of course. The third thing is there are a number of medications that can be used to treat these symptoms of orthostatic hypotension. So mestinon is commonly used, Florinef, Midodrine has better evidence than Florinef, but I use all of them or both of them. And then, of course, Northera is a medication that can be used as well. With regards to other features of autonomic dysfunction, constipation must be treated. Miralax is a commonly used drug. Hydration can initially, or starting of dopaminergic treatment can initially at least help with some symptoms of constipation. I have a very low threshold to refer my patients to urology or urogynecology for issues of GI, GU autonomic dysfunction.

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