Functional Neurological Disorder (FND) encompasses a diverse range of symptoms including limb weakness and movement disorders, non-epileptic and dissociative attacks, sensory problems, cognitive problems, visual and speech symptoms.
Whilst the symptoms may appear similar to neurological diseases including those of Multiple Sclerosis, Parkinson’s and Epilepsy, and can be just as debilitating, they are not caused by structural disease of the nervous system, but a problem with the “functioning” of the nervous system.
The structure of the body is fine, but there is a problem with how the nervous system is functioning and how the brain fails to send and receive messages correctly. This impacts on how the body responds to different tasks such as, for example, movement control. The Hoovers Sign, which is a specific test with regards to functional limb weakness, illustrates this response as a positive physical sign. Whilst traditional MRIs cannot detect functional neurological symptoms and patients are confused with a “clear” brain scan, research studies are beginning to produce evidence of the differences occurring in the brains of people with FND.
FND is a complex but common condition. It overlaps both neurology and psychology and this is reflected in the confusing array of terminology that has developed over the years. As understanding of functional neurological symptoms has advanced, so has the debate amongst medical professionals regarding the diagnostic criteria and terminology.
Historically, past trauma was thought to be the only factor that influenced the development of functional neurological symptoms, but research findings are indicating this is not the case for everyone. Current understanding is that biological, psychological and social factors may contribute towards a person’s vulnerability to developing FND. Further research is needed to ascertain a clearer picture of the cause of FND.
To learn more about FND please visit the neurosymptoms website which is a key resource in the UK and worldwide, and is written by a leading specialist in this field.
CLICK HERE for information about symptoms.
 Maurer CW, Et al. Grey matter differences in patients with functional movement disorders. NCBI The Official Journal of the American Academy of Neurology, 2018 Nov 13, 91(20):e1870-e1879
 Stone. Et al. Functional disorders in the Neurology section of ICD-11. A landmark opportunity NCBI The Official Journal of the American Academy of Neurology, 2014 Dec 9, 83(24): 2299-2301