Anne-Catherine M L Huys1, Patrick Haggard2, Kailash P Bhatia3, Mark J Edwards4. 1. Department of Clinical and Movement Neurosciences, University College London Queen Square Institute of Neurology, 33 Queen Square, London, WC1N 3BG, UK. anne-catherine.huys.15@alumni.ucl.ac.uk. 2. Institute of Cognitive Neuroscience, University College London, London, UK. 3. Department of Clinical and Movement Neurosciences, University College London Queen Square Institute of Neurology, 33 Queen Square, London, WC1N 3BG, UK. 4. Neuroscience Research Centre, Institute of Molecular and Cell Sciences, St George's University of London, London, UK.
Abstract
BACKGROUND: Symptoms of functional neurological disorder tend to be variable, yet patients often report them being present constantly and of permanently severe intensity. Furthermore, they typically worsen when they are mentioned or during clinical examination. Such phenomena are sometimes interpreted as indicating symptom exaggeration or even fabrication. METHODS: To test the notion of inaccurate symptom perception or reporting, we directly compared subjective to objective tremulousness of reaching movements in people with a functional action tremor, people with an organic action tremor and healthy controls. Identical subjective and objective measures were used, thus eliminating any potential metacognitive confounders. Furthermore, we assessed both immediate perceptual experience with a real-time perceptual task, offering the most direct comparison; and near-time retrospective reports as the latter contribute to peoples' overall judgement of their condition. RESULTS: There was no significant difference in subjective compared to objective tremor severity between the three groups for either the real-time or retrospective conditions. CONCLUSION: People with functional tremor do not perceive or report their tremor in an exaggerated manner, compared to people with an organic tremor or healthy controls. We propose that symptom exacerbation through attentional mechanisms provides an alternative explanation for findings that are frequently attributed to 'exaggeration'.
BACKGROUND: Symptoms of functional neurological disorder tend to be variable, yet patients often report them being present constantly and of permanently severe intensity. Furthermore, they typically worsen when they are mentioned or during clinical examination. Such phenomena are sometimes interpreted as indicating symptom exaggeration or even fabrication. METHODS: To test the notion of inaccurate symptom perception or reporting, we directly compared subjective to objective tremulousness of reaching movements in people with a functional action tremor, people with an organic action tremor and healthy controls. Identical subjective and objective measures were used, thus eliminating any potential metacognitive confounders. Furthermore, we assessed both immediate perceptual experience with a real-time perceptual task, offering the most direct comparison; and near-time retrospective reports as the latter contribute to peoples' overall judgement of their condition. RESULTS: There was no significant difference in subjective compared to objective tremor severity between the three groups for either the real-time or retrospective conditions. CONCLUSION: People with functional tremor do not perceive or report their tremor in an exaggerated manner, compared to people with an organic tremor or healthy controls. We propose that symptom exacerbation through attentional mechanisms provides an alternative explanation for findings that are frequently attributed to 'exaggeration'.
Authors: Anne-Catherine M L Huys; Brianna Beck; Patrick Haggard; Kailash P Bhatia; Mark J Edwards Journal: Eur J Neurol Date: 2021-03-26 Impact factor: 6.089