Psychogenic tremor is the most common psychogenic movement disorder and accounts for up to 40 % of all psychogenic movement disorders. Patients suffering from psychogenic tremor may show positive clinical criteria like acute onset, distractibility, inconsistent frequency and amplitude of tremor or an intermittent occurrence. (Dafotakis, 2008) Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, history of other somatic symptom and secondary gain. (Hallett , 2015)
Psychogenic tremor is the most common form (55%) of all psychogenic movement disorders. Almost 75% of presenting patients are female. Onset is often abrupt. Preceding events include work related injuries and other accidents. (Bhatia, 2007)
Psychogenic tremor should be considered in the differential diagnosis of patients presenting with tremor, particularly if it is of abrupt onset, intermittent, variable and not congruous with organic tremor. (Thenganatt, 2014) The most common features include the variability of frequency and amplitude. Clinical examination should include different types of distraction including motor or cognitive tasks or testing the influence of suggestibility on tremor amplitude, frequency or direction. Patients often report sudden onset and remissions that may last for months or even years. (Zeuner et a, 2018)
NOTE: Co-morbidity with psychiatric disorders is common and includes somatoform disorders (35%), such as pain, diffuse sensory loss, conversion disorders and depression (14%). One fifth (21%) of patients are involved in litigation or compensation issues. (Bhatia, 2007)
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Bhatia KP, Schneider SA. Psychogenic tremor and related disorders. J Neurol. 2007 May;254(5):569-74. doi: 10.1007/s00415-006-0348-z. Epub 2007 Apr 9. PMID: 17417745.
Thenganatt MA, Jankovic J. Psychogenic tremor: a video guide to its distinguishing features. Tremor Other Hyperkinet Mov (N Y). 2014 Aug 27;4:253. doi: 10.7916/D8FJ2F0Q. PMID: 25243097; PMCID: PMC4161970.
Zeuner KE, Schmidt R, Schwingenschuh P. Klinische und kognitive Neurologie des funktionellen (psychogenen) Tremors [Clinical and cognitive aspects of functional (psychogenic) tremor]. Nervenarzt. 2018 Apr;89(4):400-407. German. doi: 10.1007/s00115-017-0476-y. PMID: 29327097.
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