Kyla Madonna Kenney (2:22)

put your hands out. And I did. I got my right arm shaking and my left hand was steady.

Emily Kwong (2:27)

And then he told her to focus her attention on her other arm, the one that wasn't shaking. With her steady hand, Dr. Prez guided her to start tapping her thumb and point her finger together.

Kyla Madonna Kenney (2:39)

My right hand tremor stopped like immediately. And I looked at him and I said, why did it stop? I said, you don't understand. I'm not faking this. I don't want you to think I've been faking. I'm not okay. And he said, I know what you have. This is functional neurological disorder. And I'm crying. And he said, we can help you. And I had never heard those words.

Emily Kwong (3:01)

The symptoms that come with functional neurological disorder, or fnd, are one of the top reasons people visit neurologists at all. But it happens that the disorder is missed, even though it is more common than other neurological conditions, including ALS or Lou Gehrig's disease and multiple sclerosis. Today on the show, why everyone needs to know about functional neurological disorder, a disease often missed by medical providers that challenges our understanding of the brain body connection. We speak with Kyla's doctor David Perez. I'm Emily Kwong, and you're listening to Short Wave, the science podcast from NPR.

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Emily Kwong (5:28)

All right. I am here with Dr. David Perez of Massachusetts General Hospital, Brigham and Harvard University. He is the person who finally recognized Kyla's symptoms for what they were functional neurological disorder, or fnd. Just to ease us all into what this disease looks like, I want to start with an analogy. So, David, if the brain is like A computer. What then is fnd?

Dr. David Perez (5:51)

Great place to start. One of the classic metaphors is this notion that the hardware is healthy, but the software is crashing. Another metaphor is this notion of brain mind, body overload. That may be at times when our brain circuits and our bodies reach certain thresholds of its capacity that brain circuits become a bit scrambled and glitchy. When I talk to people about this, I'll highlight. Is FND a neurologic condition? Yes. Is FND a psychiatric condition? Yes. Is FND a psychological condition? Yes.

Emily Kwong (6:29)

Wow. All of the above.

Dr. David Perez (6:30)

But very importantly, each of those statements by itself in isolation is incomplete. We try to put various diagnoses in buckets, but what do you do when a given condition kind of violates those traditional conceptualizations of what a neurologic condition is and what a psychiatric condition is? And what's also critical is this lens of physical health meets mental health, of eroding these boundaries. This is something that's critical for many, many conditions. I just think FND is so striking in how it challenges this artificial dualism that we have in medicine and society that really doesn't serve our patients well and frankly, doesn't serve science and clinical practice well either.

Emily Kwong (7:18)

Yeah. And when someone with FND has a flare up, just this onset of symptoms of dizziness or weakness or movement, they can't control, like tremors, what is happening then in their brain.

Dr. David Perez (7:28)

You can imagine with the hardware software analogy, there are many ways to crash the system that at the end of the day might lead to an alert in your computer. Right. We can sort of think about functional neurological disorder being a final common pathway of a glitchy brain. But how you got there, I think varies patient to patient.

Emily Kwong (7:48)

Given that it does vary so much patient to patient, who then is at risk for fnd?

Dr. David Perez (7:54)

Yeah, that's where you want to think about biological factors, psychological factors, social, cultural, spiritual factors. The piece there that maybe I just want to spend a moment on to dispel is this notion that childhood maltreatment or adverse life experiences are a definitive and required risk factor for the development of functional neurological disorder. Okay, that's not true.

Emily Kwong (8:21)

Yeah, fascinating. When I read about FND for the first time, I was amazed because doctors thought fnd, they called it hysteria in an earlier time period. What have doctors thought FND was throughout time?

Dr. David Perez (8:36)

It's a complex history. It's received many different terms and labels. Psychogenic illness, medically unexplained symptoms, physical problems related to a wandering womb. The other framing that has been fairly pervasive is this notion of conversion disorder, the sense that there is psychological conflict and then psychological conflict is being converted into physical symptoms with thoughts that if you addressed the psychological conflict, then the physical symptoms might resolve. So that's a really significant oversimplification in both neurology and psychiatry have this shared origin story of an interest in functional neurological disorder. But as the history evolved, the fields of neurology and psychiatry separated this separation. What it did was create a big gulf and a big gap for patients who kind of didn't quite fit into the lens of one discipline or the other.

Emily Kwong (9:38)

And it was a diagnosis of exclusion. Sometimes conversion disorder could be just the thing that's said when nothing else quite fits at certain moments in its history.

Dr. David Perez (9:49)

That's right. That approach of a diagnosis of exclusion is not how we do it today.

Emily Kwong (9:54)

Yeah. What had to change in medicine for FND to finally be recognized?

Dr. David Perez (10:00)

I think there's been a couple of pivotal things. One is this use of a rule and approach that it's no longer a diagnosis of exclusion. It's no longer a medical mystery, that there are signs we can look for to diagnose this condition with confidence and clarity. The other pieces, too, were a removal of this notion that somehow physical symptoms, functional neurologic symptoms, began in the context of a psychological stressor. It turns out, actually now there's an increasing literature to suggest that oftentimes the trigger can be a physical injury.

Emily Kwong (10:37)

Yeah, big shift. And I understand the work of Dr. Mark Hallett was pretty important to revolutionizing how FND was seen in medicine. I mean, among many things that Mark Hallett realized was that when these patients were saying they didn't feel in control of their movement, of what was happening to their bodies, but showed no evidence of, like, a physical issue or a lesion in their brain or spinal cord, they weren't kidding. Like, voluntary muscle movement can be interrupted in more than one way. He believed them. And that is a pretty brave stance to take as a doctor to say, I believe these patients, even if we can't physically see the reason why they're having these tremors.

Dr. David Perez (11:14)

Such a brave stance. And really, really important. Right, for. For a doctor, for a scientist to say, I see you, I hear you. And yes, Mark Hallett put on the map this notion that maybe one of the neuroscience themes that goes awry in patients with functional tremor and functional movement disorder is an abnormality in one's sense of agency or action. Authorship. We take for granted that when we move right closely, coupled to our movement is this sense that I am the agent of that movement. So Mark Hallett, Valerie Voon and colleagues, they observed that there were activation abnormalities in the right temporal parietal junction. And there were problems with how that brain area was talking to other brain areas, in particular some basic sensory motor areas.

Emily Kwong (12:16)

Yeah, actually I want to talk about activation abnormalities and one of the tests for FND that really reveals this, the Hoover sign tests. Listeners should look it up because it's very hard to explain this test without seeing it. But it basically involves testing the strength of patient's legs. And if FND affects one of their legs, that leg is weak when it's directly tested. But when the strong leg is consciously tested instead, when the participant is told like, okay, focus on your strong leg, the weak leg's strength temporarily returns, which is very cool. And I'm curious, David, what do you think this test reveals about the brain body connection and what's going on with

Dr. David Perez (12:56)

this condition that tells you, by leveraging a reflex, that the basic pathways for motor control are intact?

Emily Kwong (13:06)

Yeah.

Dr. David Perez (13:06)

And the notion here in functional neurological disorder is that the basic motor pathways are intact, but other brain networks are intruding and hijacking on those basic motor pathways. That's the framing biologically of a functional neurological disorder.

Emily Kwong (13:28)

That is such a clever way to diagnose FND because it is often been missed. FND was only added to the DSM in 2013.

Dr. David Perez (13:37)

That's right.

Emily Kwong (13:38)

What do we know now about some of the best practices for treating people and caring for people who have this condition?

Dr. David Perez (13:44)

The first step is making sure that the patient and the family members and other supports are really given some educational information about fnd. And then when I think about FND care, what it really benefits from is thinking. Do you have an expert on the neurology side that's weighing in on your examination? Do you have an expert on the mental health side that's weighing in on the context and are they working together? There's an element of brain retraining and motor retraining, and that happens through physical therapy, occupational therapy, and speech and language pathology. And then as we think about brain retraining, that's where skills based psychotherapy, or what one form of that is called cognitive behavioral therapy, that's oftentimes coupled with physical treatments too. These are some of the things that I think are important.

Emily Kwong (14:44)

What I learned from David is that every FND treatment plan needs to be different because every person's case is so different. For Kyla, what has helped is a combination of things. Meditating, knowing what triggers her symptoms and doing cognitive behavioral therapy therapy. There's a special kind of cognitive behavioral therapy just for people with fnd. Talking to other people with this condition also helps. She and one of her friends call each other the FN Divas. And because she's a musician, she's also shared her experience through song, giving a name to a condition that was once so mysterious to her and a voice to her journey of finally being believed.

Kyla Madonna Kenney (15:23)

But I was relentless. I had to fight for my life. No one could see the terror in me. I had to find someone who would believe. I found a place. They listened to me. For the first time in my life,

Emily Kwong (15:53)

I am Shortwavers Share this episode with a friend, a colleague, so that people who need this sciency goodness in their lives can join the shortwave community. This episode was produced by Arundhati Nair. It was edited by our showrunner, Rebecca Ramirez. Tyler Jones Check the facts. I'm Emily Kwong. Thank you for listening to Short Wave, the science podcast from npr.

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