Les affections psychosomatiques constituent-elles une catégorie utopique ? À propos des troubles neurologiques fonctionnels et de l’hypothèse de l’erreur de discrétisation

Among psychosomatic conditions, functional neurological disorders (FND) are very
common, sometimes in the form of conversion, sometimes in that of somatization. They
should be differentiated from factitious disorders and malingering. Four clinical cases are
presented to illustrate the current state of our knowledge on the subject.
Secondly, the use of placebo for diagnostic or therapeutic purposes is discouraged
in FND. However, a link is established here between functional disorders and the placebo
effect. This link is confirmed by functional brain imaging (the region of the dorsolateral
prefrontal cortex is of particular interest), as well as genetics studies (tryptophan
hydroxylase 2 [TPH2] gene polymorphism G703T). This results in FND and the placebo
effect belonging to the same utopian family, sharing a similar physiology: the House of
Utopia.
Finally, the aetiology of FND is discussed and an original hypothesis is presented:
the implication of a discretization error in the unconscious management of interoceptive
and proprioceptive sensory data, which would result in the transmission at the conscious
level of an altered avatar of the bodily representation, mistakenly identified as a somatic
disorder. The same process would be at work in the placebo effect.