The topic of “dysautonomia” is a very popular one amongst people with hereditary connective tissue disorders like Ehlers-Danlos syndrome (EDS) and hypermobility spectrum disorders (HSD). Yet in spite of the significant comorbidity between EDS/HSD and autism, dysautonomias are not much of a talking point in the autism community. Yet.
Would it surprise you to know that the majority of autistic people exhibit some kind of autonomic dysregulation and that this can affect all sorts of things like anxiety, gastrointestinal function, and even the immune system? First off, if you’re not coming from within the EDS/HSD community you may be wondering, “What the heck does ‘autonomic’ mean???” Here’s where you get a little bit of a neuroanatomy lesson, so buckle up.
The nervous system is divided into two main branches: the central nervous system (CNS), which is composed of your brain and spinal cord, and the peripheral nervous system (PNS), which are all the nerves that run out into your body and connect all your organs, etc., back to your spinal cord. Your PNS is further divided into the “motor” and “sensory” branches. The motor branch is basically outgoing information and the sensory is mostly incoming information. Here, we’ll focus on the motor component.
The motor branch is divided into the somatic nervous system (SNS), which controls your voluntary muscle movements, and the autonomic nervous system (ANS), which is basically all those little involuntary functions you don’t have to think about in order for them to work. That includes things like cardiac function, temperature regulation, and digestion, all of which require nerve input in order to occur.
When we use the terms “dysautonomia,” “autonomic disorder,” or “autonomic dysfunction/dysregulation,” we’re basically just saying that the ANS is doing something it shouldn’t be doing. This can either be an actual dysfunction in the ANS itself (primary) or the ANS is reacting to something else that’s going wrong in the body and thereby creating problems (secondary).
The ANS is involved in things like:
- maintaining body temperature
- regulating breathing
- moderating blood pressure and heart rate
- orchestrating digestion
- controlling bodily excretions (e.g., sweat)
- regulating sexual arousal
When the ANS is dysfunctional or dysregulated, it can lead to symptoms such as:
- fainting or dizziness
- fast or slow heartbeat (often postural)
- drops in blood pressure (often postural)
- gastrointestinal problems (reflux, nausea, diarrhea, constipation, and even gastroparesis)
- exercise intolerance
- shortness of breath
- anxiety and mood changes
- frequent urination
- disrupted sleep
- muscle tremors
- brain fog
- problems regulating body temperature
- sensory sensitivity, especially to light and sound
Each of these symptoms can seem somewhat nonspecific and almost all people have experienced issues with these at one time or another, so it’s easy to see how dysautonomias are often missed by doctors. But if you have many of these symptoms on a chronic basis, you may have a dysautonomia.
What about autism? In order to understand what’s going on, we need to split the ANS into two further branches: the sympathetic (SNS) and parasympathetic nervous systems (PSNS). The SNS is basically responsible for all the automated behaviors associated with “fight or flight.” Meanwhile, the PSNS is the “rest and digest” branch.
In autism, it appears that the SNS or fight-and-flight branch is overactivated, often at the expense of the rest-and-digest branch. Is it any wonder then that anxiety is such a pervasive problem in this group of people who are often in a state of fight-and-flight? It also causes one to wonder: Is the anxiety in autism always the result of the brain or might it sometimes be the peripheral system telling the brain it should be anxious? For example, have you ever had a panic attack because your heart started racing rather than the other way around? It’s hard for the brain to ignore these kinds of physical cues that are normally associated with anxiety and it tends to just go along.
Last year, I attended an autism think tank in which the entire session was devoted to autonomic issues in autism. So there is slowly growing interest in dysautonomias in the spectrum. But although it’s a very popular topic in EDS/HSD, it’s still not mainstream in autism yet. And I suspect that may not happen until autistic people and their families start demanding that medical research expand its focus and I encourage you all to do so. After all, these are issues that impact quality of life and overall health in a large portion of the spectrum and something that I think almost anybody can agree needs serious attention.