BMJ Case Reports 2017; doi:10.1136/bcr-2016-218956
  • Rare disease

Chewing-induced facial dystonia: a rare presentation of task-specific dystonia

  1. Kaushik Kumar Rana
  1. Department of Neurology, Sawai Man Singh Medical College and Hospital, Jaipur, Rajasthan, India
  1. Correspondence to Dr Banshi Lal Kumawat, kumawatbl04{at}
  • Accepted 6 June 2017
  • Published 17 July 2017


This case is an addition to scarce literature available for a rare condition, chewing-induced task-specific dystonia. The patient was a 63-year-old woman who presented with a 4-year history of progressive difficulty in eating food only during chewing associated with abnormal facial grimaces without any difficulty in drinking, swallowing, speaking or singing. Examination revealed dystonia of facial muscles every time she chewed but absent during drinking and speaking. As movements were consistent and reproducible with the specific task, other differential diagnosis like motor tics, psychogenic disorder, tardive dystonia and parkinsonism syndrome were excluded leading to a diagnosis of task-specific facial dystonia triggered by chewing. Treatment was started with trihexyphenidyl and later on tetrabenazine was also added but she got only mild relief of symptoms. As she did not agreed for botulinum toxin therapy, so we continued with the same treatment without much improvement.


  • Contributors All authors: manuscript preparation and reviewed the manuscript. AG: prepared and edited the manuscript.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

Register for free content

The full text of all Editor's Choice articles and summaries of every article are free without registration

The full text of Images in ... articles are free to registered users

Only fellows can access the full text of case reports (apart from Editor's Choice) - become a fellow today, or encourage your institution to, so that together we can grow and develop this resource

Don't forget to sign up for content alerts so you keep up to date with all the case reports as they are published, and let us know what you think by commenting on the Editor's blog

Navigate This Article