Editorial: Advances in rehabilitation for functional neurological disorder, 2022, Mark

Functional Neurological Disorder (FND) has mystified clinicians since antiquity, owing to its intermittent disturbances within the (usually) alert, attentive patient, as well as its lack of defining biomarkers following routine instrumented assessments (structural brain MRI in the individual patient at clinical magnetic field strengths, electroencephalography). Consequently, the etiology for FND (if there is only one) has not been conclusive, in contrast for many other common neurological disorders that are commonly associated with objective biomarkers. For example, focal structural lesions evident on the individual patient’s brain or spinal structural MRI at conventional magnetic field strengths are often associated with characteristic, relatively stable neurological deficits; epileptic seizures coincide with characteristic and distinctive episodic waveforms on electroencephalography.

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However, it would be hard to name another illness that has been more under- or mis-treated. At present the majority of clinicians who may initially evaluate persons with FND are not trained for its management. One should, however, recognize that many observations of FND suggest that it is truly a neurological disorder: (1) Persons with FND are desperate for treatment. Individuals who are truly malingering would not likely go through the arduous process of serial evaluations and attempts at therapy, bouncing from practitioner to practitioner, as occurs with persons with FND. (2) A few reports have indicated acute severe neurological deficits in domesticated animals, following physical or emotional trauma, that completely reversed through behavioral intervention. This argues against a process of psychiatric “conversion” of symptoms that originate from early life trauma and subsequent suppression of unconscious experiences. Moreover, some of the leading characteristics of FND, particularly episodic immobility or non-combative hyperkinetic movements, occur commonly as anti-predator behaviors in terrestrial vertebrates or avians, either to simulate death (to deter would-be predators that typically avoid feasting on dead potential prey) or mimic being lame (to distract predators from the nest). These are instinctive, non-learned behaviors that have survival value, a consequence of natural selection. This raises the possibility that similar involuntary phenomena can occur in some humans as well, following acute emotional or physical trauma. (3) A few studies have shown that either FND patients or neurologically healthy individuals, when asked to simulate specific neurological deficits, have altered cerebral cortical physiological activation patterns that are distinct from the patterns in FND patients when they are not prompted to produce their neurological symptoms. (4) Numerous structural brain MRI scan studies likewise have demonstrated significantly abnormal structures (either regional expansion or atrophy) among persons who are diagnosed with FND. These anomalies are not evident in the individual but emerge from statistical quantitative averaging of structural brain MRI signals at the group level.

Open access, https://content.iospress.com/articles/neurorehabilitation/nre228001

 

They make a big thing nowadays that physical or emotional trauma need not be present to diagnose any "phenotype" of FND.

Then we have

How can diseases be called functional because there are no structural abnormalities then show structural abnormalities.

Do these people ever read what they have written? One little step at a time and you get to cloud cuckoo land.

 

Maybe they have the strongest belief on their theories nothing can be shown to disprove them only to increase their beliefs.
So actual scientific evidence can disprove them proves they were actual pseudo-science