I thought I knew what functional neurologic disorder really was – a chronically activated sympathetic nervous system that manifested disruptive, neurologic-like symptoms. And somehow, simply knowing that magically would make symptoms go away. And it did, for a while. Nearly for an entire year.

But this was an oversimplification; it’s a little more nuanced. Childhood trauma and continued, chronic stress were the environmental factors that contributed to its onset and shaped (predisposed) the brain, but they are not the direct mechanism by which a ”seizure” happens. In fact, we don’t really know for sure how it happens, but we have some theories.

I learned about the active inference model of functional neurologic disorder, and as a patient, it blew my mind. It changed how I viewed the entire disorder. It’s not some broken way of thinking or some invisible wound on some specific part of my brain. Instead, it’s probably something closer to this:

Integral to the active inference model of FND are inter-related changes in:

• Attention.
• Agency
• Emotional processing.
• Sensory processing including interoception.¹

My patient interpretation of studies so far is that FND is the product of an atypical pattern of connectivity strengths in the brain; some connectivity is bolstered, and others are weakened or hypoactive, in response to what life historically demanded from the individual. Maybe with a sprinkle of luck (I.e. genetics) in there. Let me explain.

Agency #

I spoke about predictive processing a couple posts ago, but I’m going to take it one step further. I want to talk about Agency and Priors. Courtesy of Phillips again¹:

Agency is our awareness that our actions are our own, and can be implicit (a feeling of agency) or explicit (an expressed judgement). When there is a gap between what we expect will happen (the prior) and what actually happens (the resulting perception or movement), as in FND, our sense of agency is disrupted.

Agency is ultimately why we cannot tickle ourselves. Your friend tickles you, you laugh. If you tickle you, mimicking your friend’s hand movements exactly, you don’t laugh (or maybe you do, you weirdo.) Your own tickling feels fundamentally different than if done by someone else. This is because agency directly impacts sensory attenuation, “the reduction in sensation when the action is mediated by ourselves”¹.

The cool thing about sensory attenuation is that it is a metric we can actually measure in studies, so experimenters did exactly that²³.

Patients have a reduction in sensory attenuation in experimental studies reflecting reduced agency. Subjects were asked to gauge the force required to press on their fingertips, when pressing directly or when pressing via a robotic hand (as if being pressed by someone else).[Pareés et al. 2014]² Controls press harder directly because of sensory attenuation. Patients do not—they have less agency, so less sensory attenuation, so do not need to press harder. A second experiment essentially replicated the first but using sensory evoked potentials.[Macerollo et al. 2015]³

So: Patients with a functional neurologic disorder (which includes functional movement disorder) unconsciously have measurably less agency over their own movements.

My interpretation of this: If your body’s movements feel externally generated rather than self-authored, your brain may fail to generate the appropriate motor suppression signals. This could mean that runaway motor/autonomic patterns that normally get attenuated, don’t.

But I would be remiss if I didn’t highlight a few important things against these two studies:

• The sample sizes were very small, one with 17 and the other with 30.
• Correlation vs. Causation: Were outcomes because of the functional neurologic disorder, or from frequent comorbid afflictions such as anxiety/depression? Would outcomes have been the same if the participant had an organic (i.e., not functional) movement disorder?
  • (Studies can adjust for these with Clinical Controls, but they both only had FND/FMD patients and healthy controls.)
• In the second study by Macerollo et al., they also exclude the most common subset of folks with functional movement disorder: those with a tremor. I get why, but we can’t have a full understanding of the implications.

Even with these flaws in mind, as a patient myself, the results are nonetheless fascinating. And an interesting thought came to mind: What would a panic attack feel like to me if the sensations felt external, rather than internal? Could my “seizures” be panic attacks, or a precursor to one, but simply interpreted differently before it comes to my awareness? And as they continued to happen, the symptoms became more intense and severe as the priors were reinforced?

Maybe A Medically Problematic Table by Totally Not a Doctor #

Hear me out. What if initially, the seizures were actually panic attacks interpreted differently pre-consciously?

Let’s say this is true (because again, we don’t actually know how this works). Does this mean I was getting panic attacks throughout the day at seemingly random times? Maybe, but in my opinion, not necessarily. I think it only needed to happen once or twice, and then my attentional spotlight made me vulnerable to being triggered by a wider breadth of somatic sensations.

In other words,

paying attention to the sensations + priors/beliefs/fears formed about what was happening = amplified “symptoms”

This was originally unbeknownst to me, and magic fell away when I became “knownst” at Mayo Clinic. My symptoms went away, I got more help for my anxiety, and went on a journey to attempt living a healthier and more balanced life.

The model I just described explains how an FND “seizure” like mine happens. What it doesn’t explain is why one would come back after ten months of remission. That’s where caretaking comes in.

Lashing Out #

It’s March 2026 and it has been ten months since I went to the Mayo Clinic. It had also been about four months since my sister and I moved into a new house.

My sister, with her dependent personality disorder, was already struggling with the new boundaries I was putting into place over the past months. She had to learn how to rely on herself and her care team more to regulate emotions. Unfortunately, this also meant she lashed out at me more and, interpreting boundaries as a sign of abandonment, began using threats of self-harm to get me to engage with her on her terms. That’s the thing with DPD – abandonment, real or perceived, genuinely feels like life or death. While threats of self-harm could be interpreted as manipulation, it would be far more accurate to say she was spending most of her time emotionally dysregulated. She was suffering enough to think about it, even though she had no intentions to act on it.

I wasn’t taking this very well either. Healthy boundaries were required for my own sanity and health (as Mayo Clinic proved), but employing them made my sister regress and emotionally manipulate me more. Unlike a bad boyfriend, I can’t run away from her antics nor my own home. We somehow had to make our relationship healthier while navigating us emotionally triggering each other at home.

Meanwhile, I sank the energy I had left into a second application to the Division of Developmental Disabilities, or DDD. The first one I sent in seven years ago when my sister came into my care was rejected (story for another post). She had her care team and some services by virtue of schizophrenia giving her an SMI (Severely Mentally Ill) designation, but the services she was really needing that would help her live independently from me and make friends was behind DDD.

The problem is that it’s a difficult endeavor to prove someone was on the spectrum as a child when they are now nearly 40. Autism Spectrum Disorder didn’t even exist back then. For her, it was called Pervasive Developmental Disorder Not-Otherwise-Specified (PDD-NOS).

I ran into the same wall I had the first time: I did not have the record for a qualifying full autism evaluation by a qualified assessor for my sister. I had a dusty box of IEPs and multidisciplinary evaluations from schooling. I had plenty of records from various inpatient psychiatric stays and outpatient reports from ages two through her twenty-two. I had reports from the job programs she took part in her thirties (which ultimately did not pan out; it was too much for her). I had lots of literature from before she was 18 years old that documented the challenges she had, including documented mentions of PDD-NOS.

But I needed a Very Special, Specific Autism Evaluation Document for the PDD-NOS. That was not in my dusty box of records.

Something different with DDD this time around was that the autism evaluation did not have to be from prior to 18 years old. I could get a new Very Special, Specific Autism Evaluation at her current age of 37 and submit it. Ah-ha! Do-able! No time machine required!

And so off we went – a quick two hour drive to Phoenix and several thousand dollars later, we completed the evaluation. My sister was a trooper; it is no fun being mentally poked and prodded and tested by professionals without taking some bruising on your self-worth.

A few weeks later, we met with the psychologist over Zoom and were verbally delivered the results.

Results #

Her documented pervasive developmental disorder from the DSM-IV was now promoted to the DSM-5’s autism spectrum disorder, level two (requires substantial support). In addition to this, she also got the diagnostic code for borderline intellectual functioning, indicating she needs additional support in that pathway, but not at the level of a true cognitive disability.

This was fantastic news. We’re going to receive the Very Special Evaluation in a few weeks and will be able to continue our application with DDD. Services so she can make friends! Live independently! Get more support!

She cried. I cried. A lot. Both she and I were so used to doing gymnastics through the behavioral health system, getting rejections and no’s. It would take me a few days to really believe it. But then something interesting happened.

The news alone doesn’t “make my sister better” or reduce her needs. She was still struggling and lashing out (and inwards). She was still threatening self-harm despite having no intention to act. Something in me snapped.

One Waiting Room to Another #

I’ve been in a lot of waiting rooms over my life. Waiting rooms for my mom, my sister, for child psychologists, therapists, spontaneous ER visits, oncologists, and so on. In its own way, the last eight years taking sole care of my sister was like one big waiting room, waiting for this moment where we could finally catch a break. Where she can receive the services that would help her live independently.

Receiving the official, modern autism spectrum diagnosis was like finally being called in after being in the waiting room all day. “Finally”, I thought, “my life can go on.” There was a future where I was not constantly pushed to be Caretaker first, Shannon second.

But instead, I was taken into another waiting room where I would wait some unknowable amount of time. Meanwhile my sister is still suffering, and I’m still struggling to keep it together. And it’s not that the caretaking itself was so awful on a given day; it wasn’t, I was an expert in taking care of adults with high support needs. But it’s the fact that now I have to wait for the evaluation to show up, then I have to re-open my case with DDD, then they will evaluate her case and either accept her or I’ll have to file an appeal, then I have to reach out to the services themselves, and I have only a faint idea of what acceptance looks like. I have no idea how many more months it’ll take before she’s in a program that gets her out of the house on a day-to-day basis. And then how many months before actual independent living?

It was another waiting room. And… frankly, I started feeling less certain I was capable of waiting anymore. I was 33. I had already decided against having children of my own because I was terrified of resetting an 18-year timer doing caretaking. I kept feeling forced to put myself last, after a lifetime of putting others first because they couldn’t survive if I didn’t. (My mom probably would have survived, but neither she nor child-me believed that.) I’ve done this so many times before; get my hopes up, then fizzle and disappointment.

It was during this time that my functional neurologic symptoms came back. Head drop seizures, post-ictal exhaustion, nearly the whole she-bang, just milder. But still just as disruptive to work.

Unfortunately, this turned my big Work Guilt Dial up numerous notches. Aww, was I too sad and anxious to go to work? “Boohoo. Suck it up”, I’d tell myself. Even though I would never say anything like that to another human.

Very rapidly, I ended up in front of my psychiatrist disheveled and struggling to coherently convey how I was feeling: The symptoms are back. I can’t think. I feel like I can barely work. We have forward momentum for my sister but it’s still hard. I don’t know how long it’s going to take, and I don’t know if I can wait. I’m idealizing leaving my situation through the only avenue I could think of, and that’s terrifying because it would crush my sister and my partner.

Use Yer Benefits #

This brings us to now, late May 2026. I’ve been on leave from work since late April. To quote one of my favorite Patton Oswalt skits, I have an “Oops! All Crunch Berries assortment” of blog post topics from trying all kinds of new-wave and old-wave things to improve my mental health and situation with my sister. I’ll glaze over them for now, and get back to what I really wanted to convey with this triad of personal posts.

Disclaimer: The following is patient opinion, given the patient’s non-professional interpretation of the science behind her FND diagnosis.

I believe my functional neurologic disorder relapsed because:

• I still had limited education on the mechanics of my own diagnosis. I had no idea about agency or prediction errors or priors, only the idea that chronic stress was the root cause.
• I had new acute stressors that felt inescapable. In addition, there were no short-term solutions like respite care, as we did not have the services available to us. There were no other adults in my life that could realistically solve this for me. Folks can help, or cheer me on, or take Amanda out of the house for a while, but in the end there is only me.
• Finally, and I really believe this is the catalyst: I started to feel intensely helpless, just like in the worst moments of my life as a child.

When I went to my psychiatrist to request help with medical leave, it felt like a minimum I needed just to survive and keep going and avoid making the ultimate choice.

In hindsight, that would have been enough to ask for help. But in my mind, my emotions were simply a burden, not critical information about my own wellbeing. The FND symptoms that inevitably returned felt like the only valid justification for taking a break from work.

And it’s worth mentioning again, when I say “FND symptoms”, I now know them as misattributed physical symptoms caused by extreme stress, thanks to predictive processing.

In my layman way, they’re the panic attacks, the reduced blood flow to my limbs from activated fight-or-flight, and the frequent and intense dissociation from simply hearing my sister down the hall. (Caregiver burnout be real, yo.) But they translate into brain fog that’s bad enough I can’t read a screen, participate in a conversation, or exhaustion where it’s hard to hold my head up or move my arms.

Isn’t that just wild?

There is so much to each of us that, when you boil it all down, is shaped by our beliefs. Our core beliefs. I feel fortunate that my life experience led me to readily believe my doctors when they told me I had FND. I readily believed that what I was experiencing was real, while also not epilepsy or some other, better understood illness.

You can’t fake that belief. But you can develop it after being submerged in taking care of a parent who believed they couldn’t get better, argued with doctors, and then proceeded to fulfill their own prophecy.

I’m not entirely sure how to end this blog post, except by saying that I’m doing a lot better now, thanks to the gracious help of my psychiatrist, my therapist, my sister and her care team, and… me. The adult-me that knows that child-me deserved someone like adult-me to save her from an impossible and helpless situation. She didn’t get that safety, but adult-me is getting it now.

Better late than never.

Usage of AI #

An LLM was used to format and verify citations/footnotes.

An LLM was used as a proofreader/editor, but did not write or directly edit any of the content above.

An LLM was used to augment my search for academic papers.