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Conversion disorder: towards a neurobiological understanding

Conversion disorders are a common cause of neurological disability, but the diagnosis remains controversial and the mechanism by which psychological stress can result in physical symptoms “unconsciously” is poorly understood. This review summarises research examining conversion disorder from a neuro...

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Detalles Bibliográficos
Autores principales: Harvey, Samuel B, Stanton, Biba R, David, Anthony S
Formato: Texto
Lenguaje:English
Publicado: Dove Medical Press 2006
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671741/
https://www.ncbi.nlm.nih.gov/pubmed/19412442
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author Harvey, Samuel B
Stanton, Biba R
David, Anthony S
author_facet Harvey, Samuel B
Stanton, Biba R
David, Anthony S
author_sort Harvey, Samuel B
collection PubMed
description Conversion disorders are a common cause of neurological disability, but the diagnosis remains controversial and the mechanism by which psychological stress can result in physical symptoms “unconsciously” is poorly understood. This review summarises research examining conversion disorder from a neurobiological perspective. Early observations suggesting a role for hemispheric specialization have not been replicated consistently. Patients with sensory conversion symptoms have normal evoked responses in primary and secondary somatosensory cortex but a reduction in the P300 potential, which is thought to reflect a lack of conscious processing of sensory stimuli. The emergence of functional imaging has provided the greatest opportunity for understanding the neural basis of conversion symptoms. Studies have been limited by small patient numbers and failure to control for confounding variables. The evidence available would suggest a broad hypothesis that frontal cortical and limbic activation associated with emotional stress may act via inhibitory basal ganglia–thalamocortical circuits to produce a deficit of conscious sensory or motor processing. The conceptual difficulties that have limited progress in this area are discussed. A better neuropsychiatric understanding of the mechanisms of conversion symptoms may improve our understanding of normal attention and volition and reduce the controversy surrounding this diagnosis.
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spelling pubmed-26717412009-04-30 Conversion disorder: towards a neurobiological understanding Harvey, Samuel B Stanton, Biba R David, Anthony S Neuropsychiatr Dis Treat Reviews Conversion disorders are a common cause of neurological disability, but the diagnosis remains controversial and the mechanism by which psychological stress can result in physical symptoms “unconsciously” is poorly understood. This review summarises research examining conversion disorder from a neurobiological perspective. Early observations suggesting a role for hemispheric specialization have not been replicated consistently. Patients with sensory conversion symptoms have normal evoked responses in primary and secondary somatosensory cortex but a reduction in the P300 potential, which is thought to reflect a lack of conscious processing of sensory stimuli. The emergence of functional imaging has provided the greatest opportunity for understanding the neural basis of conversion symptoms. Studies have been limited by small patient numbers and failure to control for confounding variables. The evidence available would suggest a broad hypothesis that frontal cortical and limbic activation associated with emotional stress may act via inhibitory basal ganglia–thalamocortical circuits to produce a deficit of conscious sensory or motor processing. The conceptual difficulties that have limited progress in this area are discussed. A better neuropsychiatric understanding of the mechanisms of conversion symptoms may improve our understanding of normal attention and volition and reduce the controversy surrounding this diagnosis. Dove Medical Press 2006-03 /pmc/articles/PMC2671741/ /pubmed/19412442 Text en © 2006 Dove Medical Press Limited. All rights reserved
spellingShingle Reviews
Harvey, Samuel B
Stanton, Biba R
David, Anthony S
Conversion disorder: towards a neurobiological understanding
title Conversion disorder: towards a neurobiological understanding
title_full Conversion disorder: towards a neurobiological understanding
title_fullStr Conversion disorder: towards a neurobiological understanding
title_full_unstemmed Conversion disorder: towards a neurobiological understanding
title_short Conversion disorder: towards a neurobiological understanding
title_sort conversion disorder: towards a neurobiological understanding
topic Reviews
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671741/
https://www.ncbi.nlm.nih.gov/pubmed/19412442
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