Oromandibular dystonia

Abnormal involuntary movements commonly affect the jaw. Oromandibular dystonia is a focal dystonia that produces a variety of abnormal movements involving the mouth, jaw and tongue: jaw opening, jaw closing, lateral movements, bruxism, facial grimacing, tongue movements and combinations of these (Video). It often occurs as part of a segmental or generalized dystonia. In a study of 240 patients, 62% had the jaw-opening type, 20% the jaw-closing type and 18% had a mixed form.(1)

The movements often interfere with chewing, speaking and swallowing. The patient in the video found that holding a straw between his teeth worked as a sensory trick and helped control the involuntary movements.

The condition is usually idiopathic, but it may be due to neuroleptic exposure, CNS trauma, neurodegenerative disorders, CNS anoxia, metabolic disorders and rarely peripheral trauma.(2,3) Meige's syndrome is oromandibular dystonia and blepharospasm. Auctioneer's jaw is a task-specific oromandibular dystonia.(4)

Video courtesy of James Gianelli, see https://www.youtube.com/watch?v=b9roso9B1F0&t=5s

References

1. Slaim L, Cohen M, Klap P, Vidailhet M, Perrin A, Brasnu D, Ayache D, Mailly M. Oromandibular Dystonia: Demographics and Clinical Data from 240 Patients. J Mov Disord. 2018;11:78-81.

2. Tan EK, Jankovic J. Tardive and idiopathic oromandibular dystonia: a clinical comparison. J Neurol Neurosurg Psychiatry. 2000;68:186-90.

3. Sankhla C, Lai EC, Jankovic J. Peripherally induced oromandibular dystonia. J Neurol Neurosurg Psychiatry. 1998;65:722-8.

4. Scolding NJ, Smith SM, Sturman S, et al. Auctioneer's jaw: a case of occupational oromandibular hemidystonia. Mov Disord 1995;10:508–509.