In Response To:
Walker RH. Reply to: Tardive dyskinesia-like syndrome due to drugs that do not block dopamine receptors: rare or non-existent: literature review. Tremor Other Hyperkinet Mov. 2019; 9. doi: 10.7916/3rez-p096
D’Abreu A, Friedman JH. Tardive dyskinesia-like syndrome due to drugs that do not block dopamine receptors: rare or non-existent: literature review. Tremor Other Hyperkinet Mov. 2018; 8. doi: 10.7916/D8FF58Z9
Response to Letter to the Editor
Keywords: Segmental dystonia, dyskinesias in the elderly, tardive syndromes, facial dyskinesias
Citation: Friedman JH, D Abreu A. Response to letter to the Editor. Tremor Other Hyperkinet Mov. 2019; 9. doi: 10.7916/0rjw-cv10
*To whom correspondence should be addressed. E-mail: Joseph_Friedman@Brown.edu
Editor: Elan D. Louis, Yale University, USA
Received: December 12, 2018 Accepted: December 13, 2018 Published: February 6, 2019
Copyright: © 2019 Friedman et al. This is an open-access article distributed under the terms of the Creative Commons Attribution–Noncommercial–No Derivatives License, which permits the user to copy, distribute, and transmit the work provided that the original authors and source are credited; that no commercial use is made of the work; and that the work is not altered or transformed.
Financial Disclosures: None.
Conflict of Interest: The authors report no conflict of interest.
Ethics Statement: Not applicable for this category of article.
To the Editor,
We appreciate Dr. Walker’s kind words for our manuscript. Our experience with spontaneous dyskinesias of the face in elderly people is not large enough to suggest one particular phenomenology over another. While we do not disagree with Dr. Walker’s experience that these are usually dystonia, we do not feel that we have the experience to either agree or disagree. However, Dr. Walker notes an estimated prevalence of 100–400 per million (0.01–0.04%) of segmental dystonia, but reports on the prevalence of spontaneous dyskinesias in elderly people have produced considerably higher estimates, generally between 1% and 4%,1,2 with the movements primarily localized to the mouth. Assuming that elderly people comprise about 14% of the American population, the prevalence in the general population should be at least 0.14–0.5%, an order of magnitude greater than Dr. Walker suggests. These reports have generally attempted to distinguish this entity from Meige’s syndrome and tardive syndromes, and have looked into edentulous status, gum disorders, and teeth disorders as contributing factors. Based on these reports, we are skeptical that many primary dystonias are being misdiagnosed, but certainly think it possible, and agree that dystonia must be considered in the differential diagnosis.
1. Kane JM, Weinhold P Kinon B, Wegner J, Leader M. Prevalence of abnormal involuntary movements (“spontaneous dyskinesias”) in the normal elderly. Psychopharmacology (Berl) 1983;77:105–108.
2. Blanchet PJ, Abdillahi O, Beauvais C, Rompré PH, Lavigne GJ. Prevalence of spontaneous oral dyskinesia in the elderly: a reappraisal. Mov Disord 2004;19:892–896. doi: 10.1002/mds.20130