Parkinsonism and Related Disorders xxx (2013) 1
Contents lists available at ScienceDirect
Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis
Correspondence
Reply to R. Erro and M. Tinazzi’s “Functional (psychogenic) paroxysms: the diagnosis is in the eye of the beholder” Keywords: Functional movement disorders Paroxysmal dyskinesia Non-epileptic seizures
Sir We read with interest Erro and Tinazzi’s commentary [1] on our recent work on the delineation of phenomenological characteristics of patients with functional (psychogenic) paroxysmal movement disorders [2]. We agree that functional neurological symptoms, regardless of the phenomenology, are likely to share fundamental pathophysiological processes, and have previously argued for this in detail [3]. However, we believe that there is still a role for phenomenological classification (even “micro-classification”) if done for the right reasons. Organic paroxysmal dyskinesias are not accompanied by EEG abnormalities and the diagnosis cannot be supported by readily available tests. Phenomenology is therefore key to the correct diagnosis, but as these are very rare conditions, many clinicians will understandably lack confidence in making a positive diagnosis and in differentiating them from other paroxysmal conditions. While epilepsy is a clear differential diagnosis and with suitable facilities such as EEG telemetry can be fairly easily ruled in or out, making the diagnosis of a functional paroxysmal movement disorder is more difficult. Therefore establishing clinical criteria to aid positive diagnosis may well be useful for general neurologists and for movement disorders specialists who might be confronted with such cases. There is a clear overlap with non-epileptic attacks, but the importance of our clinical criteria was brought home to us by the fact that six cases in our paper [2] were initially referred to epileptologists who ruled out epilepsy as a cause, but were not happy to make a diagnosis of functional non-epileptic attacks and instead requested a movement disorder opinion if the cases could be unusual presentations of organic paroxysmal dyskinesia. Hence, rather than classifying phenotypes, we propose clinical clues in order to facilitate accurate diagnosis and treatment in disorders where diagnosis still solely relies on the presence of
positive clinical criteria rather than biomarkers. We too feel that multidisciplinary collaboration between neurology, psychiatry, physiotherapy and psychology is paramount to improve outcomes for this disabled group of patients. However, multidisciplinary treatment will only ever be available to those patients who have received a clear diagnosis. We hope our work will improve the ability of neurologists to make a positive diagnosis swiftly and accurately even in the complex clinical scenario of patients with paroxysmal movement disorders.
References [1] Erro R, Tinazzi M. Functional (psychogenic) paroxysms: the diagnosis is in the eye of the beholder. Parkinsonism Relat Disord 2013, http://dx.doi.org/10.1016/ j.parkreldis.2013.10.020. [Epub ahead of print]. [2] Ganos C, Aguirregomozcorta M, Batla A, Stamelou M, Schwingenschuh P, Munchau A, et al. Psychogenic paroxysmal movement disorders - clinical features and diagnostic clues. Parkinsonism Relat Disord 2013, http://dx.doi.org/ 10.1016/j.parkreldis.2013.09.012. [Epub ahead of print]. [3] Edwards MJ, Adams RA, Brown H, Parees I, Friston KJ. A Bayesian account of ‘hysteria’. Brain 2012;135:3495e512.
Christos Ganos Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, United Kingdom Department of Neurology, University Medical Centre HamburgEppendorf (UKE), Hamburg, Germany Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany Mark Edwards, Kailash P. Bhatia* Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, United Kingdom * Corresponding author. E-mail address: [email protected] (K.P. Bhatia).
18 November 2013
DOI of original article: http://dx.doi.org/10.1016/j.parkreldis.2013.10.020. 1353-8020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.parkreldis.2013.11.015
Please cite this article in press as: Ganos C, et al., Reply to R. Erro and M. Tinazzi’s “Functional (psychogenic) paroxysms: the diagnosis is in the eye of the beholder”, Parkinsonism and Related Disorders (2013), http://dx.doi.org/10.1016/j.parkreldis.2013.11.015
Contents lists available at ScienceDirect
Parkinsonism and Related Disorders journal homepage: www.elsevier.com/locate/parkreldis
Correspondence
Reply to R. Erro and M. Tinazzi’s “Functional (psychogenic) paroxysms: the diagnosis is in the eye of the beholder” Keywords: Functional movement disorders Paroxysmal dyskinesia Non-epileptic seizures
Sir We read with interest Erro and Tinazzi’s commentary [1] on our recent work on the delineation of phenomenological characteristics of patients with functional (psychogenic) paroxysmal movement disorders [2]. We agree that functional neurological symptoms, regardless of the phenomenology, are likely to share fundamental pathophysiological processes, and have previously argued for this in detail [3]. However, we believe that there is still a role for phenomenological classification (even “micro-classification”) if done for the right reasons. Organic paroxysmal dyskinesias are not accompanied by EEG abnormalities and the diagnosis cannot be supported by readily available tests. Phenomenology is therefore key to the correct diagnosis, but as these are very rare conditions, many clinicians will understandably lack confidence in making a positive diagnosis and in differentiating them from other paroxysmal conditions. While epilepsy is a clear differential diagnosis and with suitable facilities such as EEG telemetry can be fairly easily ruled in or out, making the diagnosis of a functional paroxysmal movement disorder is more difficult. Therefore establishing clinical criteria to aid positive diagnosis may well be useful for general neurologists and for movement disorders specialists who might be confronted with such cases. There is a clear overlap with non-epileptic attacks, but the importance of our clinical criteria was brought home to us by the fact that six cases in our paper [2] were initially referred to epileptologists who ruled out epilepsy as a cause, but were not happy to make a diagnosis of functional non-epileptic attacks and instead requested a movement disorder opinion if the cases could be unusual presentations of organic paroxysmal dyskinesia. Hence, rather than classifying phenotypes, we propose clinical clues in order to facilitate accurate diagnosis and treatment in disorders where diagnosis still solely relies on the presence of
positive clinical criteria rather than biomarkers. We too feel that multidisciplinary collaboration between neurology, psychiatry, physiotherapy and psychology is paramount to improve outcomes for this disabled group of patients. However, multidisciplinary treatment will only ever be available to those patients who have received a clear diagnosis. We hope our work will improve the ability of neurologists to make a positive diagnosis swiftly and accurately even in the complex clinical scenario of patients with paroxysmal movement disorders.
References [1] Erro R, Tinazzi M. Functional (psychogenic) paroxysms: the diagnosis is in the eye of the beholder. Parkinsonism Relat Disord 2013, http://dx.doi.org/10.1016/ j.parkreldis.2013.10.020. [Epub ahead of print]. [2] Ganos C, Aguirregomozcorta M, Batla A, Stamelou M, Schwingenschuh P, Munchau A, et al. Psychogenic paroxysmal movement disorders - clinical features and diagnostic clues. Parkinsonism Relat Disord 2013, http://dx.doi.org/ 10.1016/j.parkreldis.2013.09.012. [Epub ahead of print]. [3] Edwards MJ, Adams RA, Brown H, Parees I, Friston KJ. A Bayesian account of ‘hysteria’. Brain 2012;135:3495e512.
Christos Ganos Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, United Kingdom Department of Neurology, University Medical Centre HamburgEppendorf (UKE), Hamburg, Germany Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany Mark Edwards, Kailash P. Bhatia* Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, United Kingdom * Corresponding author. E-mail address: [email protected] (K.P. Bhatia).
18 November 2013
DOI of original article: http://dx.doi.org/10.1016/j.parkreldis.2013.10.020. 1353-8020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.parkreldis.2013.11.015
Please cite this article in press as: Ganos C, et al., Reply to R. Erro and M. Tinazzi’s “Functional (psychogenic) paroxysms: the diagnosis is in the eye of the beholder”, Parkinsonism and Related Disorders (2013), http://dx.doi.org/10.1016/j.parkreldis.2013.11.015
