Basics of Chiari-Related Diseases:

DYSAUTONOMIA INFORMATION PAGE (PDF)

The autonomic nervous system controls automatic, unconscious functions—things your brain doesn’t need to actively think about to control. For example, the autonomic nervous system controls bodily functions like blood pressure and heart rate, sweating, digestion, and breathing.

Dysautonomia is the dysfunction of the autonomic nervous system. “Dysautonomia” is a broad term that can encompass multiple conditions. It occurs when the functions that your body handles automatically stop operating very well on autopilot.

There are no good estimates for the number of people who are affected since “dysautonomia” can be many things. However, some specific types of dysautonomia are a little easier to recognize. For example, orthostatic hypotension is the second most common cause of fainting, occurring in 15% of all patients who experience fainting episodes. Postural orthostatic tachycardia syndrome (POTS) occurs in about 0.2% of the general population. About 75% of POTS patients are female.

Due to a lack of awareness and because it is not well-understood, getting a diagnosis can take years for some patients.

WHAT ARE THE SYMPTOMS OF DYSAUTONOMIA?

Common symptoms of autonomic dysfunction can include abnormal heart rate, lightheadedness, fainting, digestion issues, or irregular kidney function.

A more exhaustive list of symptoms that some patients may or may not experience:

• Abnormal heart rate
• Heart palpitations
• Shortness of breath/chest pain
• Unstable blood pressure
• Low blood volume
• Syncope (fainting) or near syncope
• Lightheadedness, dizziness, or vertigo
• Nausea
• Migraines or headaches
• Difficulty swallowing
• Hypersensitivity to light, sound, touch, or smell
• Temperature control issues
• Excessive sweating
• Exercise intolerance
• Chronic fatigue
• Frequent dehydration
• Irregular kidney function
• Gastrointestinal motility issues

HOW IS DYSAUTONOMIA DIAGNOSED?

It depends on the type of dysautonomia to be identified, but let’s talk about two common forms: neurocardiogenic syncope and postural orthostatic tachycardia syndrome (POTS).

Your doctor will suggest an electrocardiogram, or “ECG”, over a longer period of time to identify a period of clinical syncope. This will not always accurately identify some types of dysautonomia, however. Sometimes, clinicians will recommend tilt-table tests, which may more clearly determine if the type of dysautonomia is POTS or some other cause. Tilt-table tests involve literally tilting a patient in different positions to see if it causes symptoms.

HOW IS DYSAUTONOMIA TREATED?

There currently is no cure for dysautonomia but patients’ symptoms can be managed to improve their quality of life.

Rarely, dysautonomia can occur secondary to other, underlying conditions like Chiari malformation, Ehlers-Danlos syndrome (EDS), and mast cell activation syndrome (MCAS). Because of this, it is sometimes possible to improve a patients’ dysautonomia symptoms by treating the underlying condition that is causing them. That is why it is so important to get a good work-up by your clinician!

CITATIONS & OTHER RESOURCES

For a good POTS explainer, the following publications were used to help develop this page and are available open-source online:

• Safavi-Naenini P, Razavi M. Postural Orthostatic Tachycardia Syndrome. Tex Heart Inst J.2020;47(1):57-9.
• Bryarly M, Phillips LT, Fu Q, Vernino S, Levine BD. Postural Orthostatic Tachycardia Syndrome: JACC Focus Seminar. J Am Coll Cardiol. 2019;73(10):1207-28.
• Sheldon RS, Grubb BP, Olshansky B, Shen W, Calkins H, Brignole M, et al. 2015 Heart Rhythm Society Expert Consensus Statement on the Diagnosis and Treatment of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia, and Vasovagal Syncope. Heart Rhythm. 2015;12(6):e41-63.

Other sources include:

• Khalid F, Yang GL, McGuire JL, Robson MJ, Foreman B, Ngwenya LB, Lorenz JN. Autonomic dysfunction following traumatic brain injury: translational insights. Neurosurg Focus. 2019;47(5):E8.
• Roma M, Marden CL, De Wandele I, Francomano CA, Rowe PC. Postural tachycardia syndrome and other forms of orthostatic intolerance in Ehlers-Danlos syndrome. Auton Neurosci. 2018;215:89-96.
• Gampa A, Upadhyay GA. Treatment of Neurocardiogenic Syncope: From Conservative to Cutting-edge. J Innov Card Rhythm Manag. 2018;9(7):3221-31.
• Goldberger JJ, Arora R, Buckley U, Shivkumar K. Autonomic Nervous System Dysfunction: JACC Focus Seminar.  J Am Coll Cardiol. 2018;73(10):1189-1206.
• Ricci F, De Caterina R, Federowski A. Orthostatic Hypotension: Epidemiology, Prognosis, and Treatment. J Am Coll Cardiol. 2015;66(7):848-60.

Reviewed on 05/2022

Interested in learning more? Check out this lecture from Dr. Peter Rowe and other lectures in our Educational Video Library.