Electrophysiologic Evaluation of Psychogenic Movement Disorders

Psychogenic movement disorders (PMD) are a group of disorders which are in the border zone between neurology and psychiatry. All necessary laboratory investigations should be done to rule out an underlying organic disorder. While clinical acumen of a trained movement disorder specialist may be suffi...

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Main Author: Pramod Kumar Pal
Format: Article
Language:English
Published: Korean Movement Disorder Society 2011-05-01
Series:Journal of Movement Disorders
Subjects:
Online Access:http://e-jmd.org/upload/jmd-4-1-21-4.pdf
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author Pramod Kumar Pal
author_facet Pramod Kumar Pal
author_sort Pramod Kumar Pal
collection DOAJ
description Psychogenic movement disorders (PMD) are a group of disorders which are in the border zone between neurology and psychiatry. All necessary laboratory investigations should be done to rule out an underlying organic disorder. While clinical acumen of a trained movement disorder specialist may be sufficient to diagnose most PMD, there are clinical situations where electrophysiological tests are required either to rule out an organic movement disorder or even diagnose a PMD. Current electrophysiological test are most useful for tremor, followed by jerks and least for spasms or dystonia. Commonly used electrophysiologic tests include multichannel surface electromyography (EMG), accelerometry, electroencephalography time locked with EMG, premovement potential (Bereitschaftspotential), and somatosensory evoked potentials. Psychogenic tremor is a low frequency tremor with variable frequency and duration of EMG bursts, entrainable, has a high coherence with voluntary movements, and presence of coactivation sign. Patients with psychogenic jerks have well organized triphasic pattern of activation of agonist and antagonist muscles. The jerks are associated with EMG bursts of long duration (usually > 70 ms), long and variable latencies in stimulus induced jerks, absence of craniocaudal pattern of muscle recruitment in apparent startle response, and often a Breitschaftspotential (premovement potential) precedes the jerk. Electrophysiological characterization of psychogenic dystonia is difficult and the tests are usually performed to rule out organic dystonia with characteristic findings. Finally, caution should be exerted in interpreting the electrophysiological tests as both false positive and false negative diagnosis of PMD may still occur.
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spelling doaj.art-68db493bfd344b939a375c5b4f08b7732023-08-02T07:55:38ZengKorean Movement Disorder SocietyJournal of Movement Disorders2005-940X2093-49392011-05-0141213210.14802/jmd.1100437Electrophysiologic Evaluation of Psychogenic Movement DisordersPramod Kumar PalPsychogenic movement disorders (PMD) are a group of disorders which are in the border zone between neurology and psychiatry. All necessary laboratory investigations should be done to rule out an underlying organic disorder. While clinical acumen of a trained movement disorder specialist may be sufficient to diagnose most PMD, there are clinical situations where electrophysiological tests are required either to rule out an organic movement disorder or even diagnose a PMD. Current electrophysiological test are most useful for tremor, followed by jerks and least for spasms or dystonia. Commonly used electrophysiologic tests include multichannel surface electromyography (EMG), accelerometry, electroencephalography time locked with EMG, premovement potential (Bereitschaftspotential), and somatosensory evoked potentials. Psychogenic tremor is a low frequency tremor with variable frequency and duration of EMG bursts, entrainable, has a high coherence with voluntary movements, and presence of coactivation sign. Patients with psychogenic jerks have well organized triphasic pattern of activation of agonist and antagonist muscles. The jerks are associated with EMG bursts of long duration (usually > 70 ms), long and variable latencies in stimulus induced jerks, absence of craniocaudal pattern of muscle recruitment in apparent startle response, and often a Breitschaftspotential (premovement potential) precedes the jerk. Electrophysiological characterization of psychogenic dystonia is difficult and the tests are usually performed to rule out organic dystonia with characteristic findings. Finally, caution should be exerted in interpreting the electrophysiological tests as both false positive and false negative diagnosis of PMD may still occur.http://e-jmd.org/upload/jmd-4-1-21-4.pdfPsychogenic movement disordersElectrophysiological tests
spellingShingle Pramod Kumar Pal
Electrophysiologic Evaluation of Psychogenic Movement Disorders
Journal of Movement Disorders
Psychogenic movement disorders
Electrophysiological tests
title Electrophysiologic Evaluation of Psychogenic Movement Disorders
title_full Electrophysiologic Evaluation of Psychogenic Movement Disorders
title_fullStr Electrophysiologic Evaluation of Psychogenic Movement Disorders
title_full_unstemmed Electrophysiologic Evaluation of Psychogenic Movement Disorders
title_short Electrophysiologic Evaluation of Psychogenic Movement Disorders
title_sort electrophysiologic evaluation of psychogenic movement disorders
topic Psychogenic movement disorders
Electrophysiological tests
url http://e-jmd.org/upload/jmd-4-1-21-4.pdf
work_keys_str_mv AT pramodkumarpal electrophysiologicevaluationofpsychogenicmovementdisorders