Brain imaging research is thriving in functional neurological disorder, 2026, Perez et al.

SNT Gatchaman

SNT Gatchaman

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Brain imaging research is thriving in functional neurological disorder
Perez; Kozlowska; Aybek

No abstract. Conclusion —

In closing, this collection of articles addresses prior gaps in the FND literature. Observations continue to support that FND is in part a problem of alterations within and across multiple brain networks – and that these findings relate to individual differences. The data for FND representing a “software” and “hardware” problem of the brain is also growing – with many nuances emerging.

Web | DOI | PDF | NeuroImage: Clinical | Open Access
 
 
I noticed this sentence also: "Observations continue to support that FND is in part a problem of alterations within and across multiple brain networks." Hasn't the FND position been that it is a "brain network' disorder--in other words, that "a problem of alterations within and across multiple brain networks" was the sole cause. So now they're claiming it is only "in part" a "brain network" problem.

Seems like a huge change. Or am I over-interpreting? I like how the article slams a dualistic framing when they are the ones who have consistently claimed it is solely a software and not a hardware problem
 
dave30th said:
Seems like a huge change. Or am I over-interpreting?
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No. And it's probably worth mapping the progression through the literature. I've just pulled some representative links from the vast number of publications. "It's psychological, but let's disguise its name" → "It's purely functional no structural problem at all see?" → "Ooh we can see the functional abnormalities" → "Umm, there's some structural change, wonder what that's about" → "Structure and function are inseparable you guys, stop being dualists."

‘Hysteria’, ‘Functional' or ‘Psychogenic’? a Survey of British Neurologists’ Preferences (1991) —

Three terms remain the most popular among neurologists when diagnosing patients who lack a neurological basis for their symptoms: 'hysteria', 'functional' and 'psychogenic'.
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What should we say to patients with symptoms unexplained by disease? The “number needed to offend” (2002) —

Many diagnostic labels that are used for symptoms unexplained by disease have the potential to offend patients. Although “medically unexplained” is scientifically neutral, it had surprisingly negative connotations for patients. Conversely, although doctors may think the term “functional” is pejorative, patients did not perceive it as such. As expected, “hysterical” had such bad connotations that its continued use is hard to justify, although it is the only term in this list that specifically excludes malingering.
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Symptoms ‘unexplained by organic disease’ in 1144 new neurology out-patients: how often does the diagnosis change at follow-up? (2009) —

There is a growing recognition that the symptoms patients present to doctors with are often not associated with the presence of an ‘organic disease’.
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Emotional stimuli and motor conversion disorder (2010) —

Conversion disorder is characterized in the Diagnostic and Statistical Manual of Mental Disorders, Version IV, 1994 by neurological signs and symptoms such as movements, seizures or sensory symptoms unrelated to an underlying neurological or medical disorder. Unexplained neurological symptoms are common and reported in 30% of general neurology clinics (Carson et al., 2000) and are the cause of prominent disability (Carson et al., 2003), yet the mechanisms are very poorly understood.
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Psychopathology and psychogenic movement disorders (2011) —

Psychogenic movement disorder is defined as abnormal movements unrelated to a medical cause and presumed related to underlying psychological factors.
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Motor and Somatosensory Conversion Disorder: A Functional Unawareness Syndrome? (2012) —

Increasingly well characterized large-scale brain networks mediating cognitive and affective processes and modulated by experience-dependent neuroplasticity provide the foundation for a neurobiological conceptualization through which to understand functional neurologic disturbances.
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The functional neuroimaging correlates of psychogenic versus organic dystonia (2013) —

we demonstrate, for the first time, that there is a distinctive pathophysiological signature shown by functional neuroimaging that separates organic from psychogenic dystonia. We also show that the prefrontal cortex is implicated in organic and psychogenic dystonia. […] Functional neuroimaging in particular offers new insights into the pathophysiology of psychogenic movement disorders, which we propose is critical to improving the diagnosis, therapy and prognosis of this major group of disabling neurological disorders.
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Current Concepts in Diagnosis and Treatment of Functional Neurological Disorders (2018) —

Functional neuroimaging has elucidated dysfunction in FNDs at the level of brain network activity, connectivity, and specific anatomic areas of altered metabolic demand during tasks.
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Psychological interventions have traditionally been considered the treatment of choice. Studies of psychological therapies have been undertaken in subpopulations with FNDs, with particularly promising results for disorder-adapted cognitive behavioral therapy for PNES and functional movement disorders, and for multimodal cognitive behavioral–informed psychotherapy for PNES, as well as cognitive behavioral therapy–oriented self-management and interdisciplinary psychodynamic interpersonal therapy for a wider range of FNDs
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A unifying theory for cognitive abnormalities in functional neurological disorders, fibromyalgia and chronic fatigue syndrome: systematic review (2018) —

We hypothesise that pain, fatigue and excessive interoceptive monitoring produce a decrease in externally directed attention. This increases susceptibility to distraction and slows information processing, interfering with cognitive function, in particular multitasking. Routine cognitive processes are experienced as unduly effortful. This may reflect a switch from an automatic to a less efficient controlled or explicit cognitive mode, a mechanism that has also been proposed for impaired motor control in FND. These experiences might then be overinterpreted due to memory perfectionism and heightened selfmonitoring of cognitive performance.
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Structural alterations in functional neurological disorder and related conditions: a software and hardware problem? (2019) —

The “software” vs. “hardware” analogy is a useful concept when discussing the diagnosis of FND with patients. According to this framing, the hardware (i.e. brain) lacks relevant structural abnormalities, however, the software (i.e. how the brain works) has a glitch that manifests in functional neurological symptoms.
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emerging data suggests that some FND and SSD cohorts show evidence of both a “software” and “hardware” problem.
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Cortical thickness in default mode network hubs correlates with clinical features of dissociative seizures (2022) —

In conclusion, the distribution of cortical thickness variations related to illness duration of DS suggests a role for potential neurodevelopmental and neuroplastic changes within the default mode network that require more research inquiry.
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Functional neurological disorder and other unexplained syndromes (2022) —

The acceptance of a biopsychosocial model in functional neurological disorder has given hope for broader acceptance of such models in medicine, perhaps even to the extent that functional neurological disorder would no longer be considered unexplained. However, by contrast, other unexplained syndromes (eg, chronic fatigue syndrome) offer a warning: their biopsychosocial model has been rejected by patient groups with such ferocity that it has become dangerous to endorse it.
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Bridging structural and functional biomarkers in functional movement disorder using network mapping (2022) —

FMD symptom severity negatively correlated with volumetric profiles in the TPJ—specifically the right supramarginal and bilateral superior temporal gyri. Atrophy network mapping showed that these structural findings preferentially impacted higher order brain areas exhibiting increased rsFC influence(weighted degree centrality) based on the healthy human functional connectome.
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Machine learning classification of functional neurological disorder using structural brain MRI features (2024) —

These findings emphasise the need to consider brain structure alongside functional neurocircuitry in the pathophysiology of FND, and establish proof-of-concept for structural brain MRI as a potential adjunctive diagnostic tool in FND.
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to present day —

The conceptualization of FND in the 20th century was fraught with dualistic perspectives of brain versus mind exemplified by outdated terms such as “hysteria” and “psychogenic”. Structure and function are closely coupled in the human brain, and neuroimaging research in FND provides an opportunity to bridge the science of brain and mind in this prevalent and potentially disabling condition
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dave30th said:
Doesn't everything in life involve differential brain networks? Wouldn't people suffering from cancer have different brain networks activiting and engaging than those without cancer?
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Absolutely. This is the problem once you start doing functional imaging. If that picks up different thoughts then, sure, someone with cancer will have different thougghts from someone invited to be a normal control.

Some of these techniques are likely to be measuring shifts in cnnection patterns that stay like that whatever thought you have but the whole thing seems pretty murky to me.
 
There has always been enormous variation within and between advocates of ‘functional’ classifications. Even individuals including Wessely will define the various groupings of symptoms in one way in one context and a completely different way in another.

It seems to me the only consistent thing is their belief that whatever this ever changing web covers is that they understand it completely and it can be cured by right thinking and exercise.
 
The slow, and clearly begrudging, acknowledgement of biological pathology is more about providing excuses for continuing to do the exact same thing they've always wanted to do: speak the right words and magically heal people who made themselves ill with their own thoughts, rather than doing anything different about it.

It's a classic motte-and-bailey. Yes, fine, sure, there is biological pathology, but this only proves how powerful the mind is, how even a single event can change/rewire how the brain works, rather than even hinting at the possibility that they just made it all up based on nothing at all the whole time. I see zero change in attitudes here. This ideology will remain absolutist until the very last second it becomes irrelevant, and will keep trying after it.

I can't really find any differences between this and "lie detectors". They've got an advanced gizmo capable of detecting changes, the rest is up to them cooking up attributions to fit the outcomes they want to achieve. It helps that the gizmos they use are actually useful for similar purposes, but this only makes it more effective. It would be like using fMRIs instead of polygraphs, the outcome is much the same: the machine can't show if someone is telling the truth or not, but people can make up all sorts of stories about it, if they want to influence the person being interrogated, who has been judged guilty until capable of proving their innocence, for which no evidence can be sufficient.

Button soup is always soup made from a single button, it doesn't matter what other ingredients go in the soup, it's the button that makes it what it is, the rest only supports the soup-making button.
 
Judging from some comments, we are about to enter the "akshually it was always firmware" phase alongside gaslighting about how functional models have always acknowledged that the brain is indeed part of the body so of course the brain is involved (the neural networks are in the brain after all!). I'm expecting neurosymptoms.org and some classic presentations to undergo a few rapid changes.

I so wish facts mattered and hypocrisy revealed would change things, but obviously this will continue to play out the same way for a while because absolutist belief systems cannot ever acknowledge being wrong. Very good expose here @dave30th. Damn do I wish facts mattered even half as much as in an average court of law here. Hell, even traffic court standards would work better.
 
rvallee said:
Judging from some comments
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Yup. That's the tenor of some of the comments on X. That "software"/"hardware" is only an analogy to make it easier for patients to understand, that no one ever said brain structures weren't involved because of course the structures are part of the brain, that I've essentially "made up" that the approach has been "software"-only even though neurosymptoms.org states definitively that it is a software and not a hardware issue, that it's not true anyone who suggested biomedical causes was accused of being "dualistic," that "dualistic" only refers to that it's abouf function and not the sort of frank lesions in other neuro diseases, as if that's the only kind of "hardware" damage one could conceive of, that of course everyone has been looking for pathophysiological causes all along, etc.
 
SNT Gatchaman said:
Wow. They really bought the li(n)e that "functional" means "related to how it functions" rather than what doctors actually mean: "purely psychological". They should probably read some of the literature clipped above in post 5.
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I guess it does go back to older uses of the word "functional." but it seems under that reasoning, a heart attack could be a "functional cardiac disorder" because it's related to poor functioning of the cariovascular system, and diabetes can be "functional insulin disorder" because it's about the malfunctioning of the insulin pathways. Every condition or disease is about the functioning of some body part or organ system.
 
We have, indeed, always, and I mean always, been at war with East Asia.
SNT Gatchaman said:
Wow. They really bought the li(n)e that "functional" means "related to how it functions" rather than what doctors actually mean: "purely psychological". They should probably read some of the literature clipped above in post 5.
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It's clearly a mix. Most patients ate the onion. Most professionals know what it meant, and no amount of pointing to clear quotes and graphs that have zero ambiguity about what they are saying will change any of that.

Because, see, we've always, and I mean always, been at war with West Asia, and we have our ancient allies in East Asia to thank for their friendship in holding this deadly foe to account.
 
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