Neurology Minute

In part three of this seven-part series on FND, Dr. Jon Stone and Dr. Gabriela Gilmour discuss causes of functional neurologic disorder.  Show citation:  Hallett M, Aybek S, Dworetzky BA, McWhirter L, Staab JP, Stone J. Functional neurological disorder: new subtypes and shared mechanisms. Lancet Neurol. 2022;21(6):537-550. doi:10.1016/S1474-4422(21)00422-1 Show transcript:  Dr. Gabriela Gilmour: This is Gabriela Gilmour with the Neurology Minute. Jon Stone and I are back to continue with part three of our seven-part series on functional neurological disorder. Today, we will focus on the causes of FND. So Jon, there have been many advances in our understanding of the mechanism of FND in the last 10, 15 years. And so what do we know about this now? Dr. Jon Stone: I think the key message I want to get across here is that whereas previously we had a very psychiatric, purely psychiatric view of FND, it used to be called conversion disorder, what we've got now is a multi-perspective view of the mechanisms, which mean that we can understand FND at a kind of neural level or brain circuit level, but we can also still retain the importance of psychological factors, traumatic events. And I think it's also important to separate out, as you've done here with a question, what's the mechanism? How is the symptom happening versus why is it happening? Which often people don't do. So for this question, how is it happening? How is it that somebody, for example, gets a weak leg? Well, at a very simple level, their brain is disconnecting from their leg and that's what dissociation is. And you can explain that to patients at sort of brain circuit level. We've learned that there are disruptions probably in the circuits in our brain that relate to that sense of agency, the parts of our brain that tell us that our bodies belong to us. And people are particularly interested in an area called the temporary parietal junction. And at a higher broader level, people are particularly interested in the idea that FND is a disorder that you would expect to happen based on our understanding of the brain as a predictive organ. So if the brain spends its time predicting things, maybe in FND what's gone wrong is this is very strong prediction that the leg is weak or that there's a tremor or that a seizure's about to happen that overrides sensory input telling our brain otherwise. Dr. Gabriela Gilmour: And I guess to follow into that, you mentioned what is going on. So now can you talk a little bit about why somebody might develop FND or the etiology of FND? Dr. Jon Stone:  I think this helps clinically as well as neurologists, because we can talk about mechanism as we would, for example, with MS as inflammation, but why is there inflammation? So okay, the brain's gone wrong, but why has it gone wrong? And there we need a much more complex view of multiple range of risk factors, predisposing, precipitating, and perpetuating that we know are associated with FND, but vary a lot from person to person. So no one person's the same. If you've had traumatic experiences in the past, that will make you more prone to dissociation. If you've had other functional disorders, if you have almost certainly some forms of genetics make people predisposed. And then as we said in the last episode, having another neurological condition, so having migraine aura, a physical injury, an infective illness, these are powerful reasons to trigger neurological symptoms. And it's not so much why they happen. It's more why do they get there and get stuck? We all probably have transient functional symptoms actually, but why they get stuck in people with FND for various reasons to do with the way their brains work or their past experiences, or sometimes what happens to them in medical systems. So developing a very open idea about why someone might have FND really helps you, I think, explain that back to patients and produce individual sort of formulations of the problem. Dr. Gabriela Gilmour: Yeah. And I often say to my patients, "I don't know exactly why you, why today have this." And that's true in medicine in general. We actually often don't know why anybody develops any medical condition with a few exceptions, but we know about risk factors really. Dr. Jon Stone: Absolutely. It's one of the reasons I hate the term medically unexplained. Actually, I think FND is perhaps more explained in some ways than some of the other conditions like multiple sclerosis and ALS that we actually deal with where we really don't know why they happen. Dr. Gabriela Gilmour: Well, we will be back for more Neurology Minute episodes to continue our discussion on FND. Thanks for listening. 

In part two of this two-part series on this year's World Stroke Congress, Dr. Andy Southerland and Dr. Seemant Chaturvedi discuss the ATLAS meta-analysis.  Learn more on the World Stroke Congress website.  Show transcript:  Dr. Andy Southerland: Hello everyone and welcome to this week's Neurology Minute. For this series, I've been speaking again with my friend and colleague, Seemant Chaturvedi, who is the director of the stroke program at the University of Maryland. And as always, Seemant is sharing hot off the presses results of presentations from this year's World Stroke Congress that was held in Barcelona, Spain in October. And for this Neurology Minute, he is going to be sharing with us the presentation of the ATLAS meta-analysis, a systematic review which looked at pulled data from multiple clinical trials and patients presenting with large vessel occlusions and large ischemic cores, looking at folks randomized between endovascular therapy and best medical management. So Seemant, what were the results of the ATLAS meta-analysis? Dr. Seemant Chaturvedi: So this was a meta-analysis of six clinical trials, which looked at patients with large core infarcts, and they evaluated the results in patients who were treated with endovascular therapy or medical therapy, and it included over 1,800 patients. The primary outcome was the shift analysis on the 90-day modified Rankin Scale, and this was favorable for a thrombectomy with an adjusted odds ratio of 1.63. In terms of the specific outcomes for modified Rankin of zero to two, this was seen in 20% with thrombectomy, 7.5% with medical therapy, for modified Rankin of zero to three, 37% with thrombectomy, and 20% with medical therapy. One important observation was that the mortality was lower with thrombectomy, 31% compared to 37%. Also, two other points worth mentioning, the cerebral hemorrhage rate was increased with thrombectomy compared to medical therapy 5.5 to 2.7%, and then we frequently wondered how big of an infarct will no longer benefit from thrombectomy. And so here, Dr. Sarraj presented the results and showed that there seemed to be some benefit up to 149 mLs and no benefit in 150 mLs or above. And so I think this gives us a lot of useful information in terms of material we can bring back to our emergency rooms for discussion with our interventional teams about who to treat, who not to treat, and about what are the realistic expectations. And so we look forward to the full publication. Dr. Andy Southerland: Well, thank you, Seemant, and it's nice to see that this full pooled analysis of these randomized clinical trials not only supports the finding of most of the individual trials, but also enhances it through increased sample size and data across trials. So as you point out, we'll look forward to the peer reviewed publication, but glad to be presented with these new data. And once again, thank you for joining us for this week's Neurology Minute, sharing your observations from the World Stroke Congress in Barcelona, Spain in October. Seek out the full podcast where we discuss these studies and more. 

In part two of this series, Dr. Jeff Ratliff and Dr. Dara Albert discuss what advice they have for people who care for patients with FND.  Show citation:  Miller R, Lidstone S, Perez DL, Albert DVF. Education Research: Targeting Self-Described Knowledge Gaps to Improve Functional Neurologic Disorder Education Among Clinicians. Neurol Educ. 2025;4(3):e200239. Published 2025 Sep 5. doi:10.1212/NE9.0000000000200239  Show transcript:  Dr. Jeff Ratliff: Hi, this is Jeff Ratliff with Neurology Minute. I'm back with Dara Albert for the second neurology minute episode following our podcast episode about her paper published in Neurology® Education titled Education Research Targeting Self-Described Knowledge Gaps to Improve Functional Neurologic Disorder Education among Clinicians. Dara, what advice do you have for people who take care of patients with FND now that you've learned about the types of knowledge gaps and misunderstandings that exist in the healthcare community about FND? Dr. Dara Albert: I think it's really important that folks recognize that FND is a real disorder, that patients are really suffering with symptoms. It's not fake, it's not feigned, it's not malingering, and that these symptoms are very real and distressing to the patients who experience them. And so that's really important for folks taking care of these patients to first and foremost to recognize. And then it's really important that we recognize that there's been an explosion in our understanding. There's been a wealth of new knowledge that has been generated about this diagnosis over the last 10 to 20 years. And so it's really important for folks that are less knowledgeable about this topic to read up and learn what we've been learning about FND and be able to approach these patients in a whole different way. Dr. Jeff Ratliff: Dara, thank you. Check out the full podcast discussion that we had about this topic to hear more details and read the paper. It's in the September, 2025 issue of Neurology® Education. This has been the Neurology Minute Daily Briefing. Thanks for listening. 

Drs. Dan Ackerman, Valérie Biousse, and Nancy J. Newman discuss the clinical presentations, diagnostic challenges, and the importance of accurate diagnosis in managing CRAO and BRAO.  Show citation: Bénard-Séguin É, Nahab F, Pendley AM, et al. Eye stroke protocol in in the emergency department. J Stroke Cerebrovasc Dis. 2024;33(9):107895. doi:10.1016/j.jstrokecerebrovasdis.2024.107895 

In part one of this two-part series on this year's World Stroke Congress, Dr. Andy Southerland and Dr. Seemant Chaturvedi discuss the TRIDENT trial.  Learn more on the World Stroke Congress website.