Clinical neurophysiology of functional motor disorders: IFCN Handbook Chapter 2024 Edwards et al

Highlights

• Functional Motor Disorders are common and disabling and diagnosis can be challenging.
  
  
• There are a range of clinical neurophysiological techniques that can assist in providing a positive diagnosis.
  
  
• Here we provide a state of the art practical review of these techniques, including established and emerging tests.

Abstract

Functional Motor Disorders are common and disabling. Clinical diagnosis has moved from one of exclusion of other causes for symptoms to one where positive clinical features on history and examination are used to make a “rule in” diagnosis wherever possible. Clinical neurophysiological assessments have developed increasing importance in assisting with this positive diagnosis, not being used simply to demonstrate normal sensory-motor pathways, but instead to demonstrate specific abnormalities that help to positively diagnose these disorders. Here we provide a practical review of these techniques, their application, interpretation and pitfalls. We also highlight particular areas where such tests are currently lacking in sensitivity and specificity, for example in people with functional dystonia and functional tic-like movements.

Open access, https://www.sciencedirect.com/science/article/pii/S2467981X24000052

 

"In general terms, FND is a disorder where the primary problem appears to be one of accessing or controlling the body normally, despite normal motivation and normal basic function of the nervous system. "

 

Reads like a bunch of rituals without much validity and even less of a theoretical foundation. Reminds me of road-side exercises that police officers sometimes use to "test" whether someone is impaired. They're not really valid either, but someone who is too drunk will definitely look obvious. But of course you always want to test blood alcohol level anyway, and they don't have anything like that here.

Frankly, this generally looks very similar to the various BS police interrogation and forensic techniques that were developed in the mid-20th century and have pretty much all been debunked. They may make some sense if you don't think about it or bother much about whether any of this is valid, but it can still take decades of being widely applied before they are properly tested and found to be no better than a mental coin toss.

 

I wonder if some of these fmds are caused by pre natal or natal brain damage that can not be seen or some kind of brain development disorder like autism.
Or a autoimmune disorders that attack the muscle or nervous systems
Or genetic disorders that cause the brain to not form properly. incomplete metabolic process that cause toxic substances to build in the body causing damage or cause some defect in the cell itself not to function properly