Four cases of Senile Oro-facial Dyskinesia and Discussion on the pathophysiology

ABSTRACT

BACKGROUND AND SIGNIFICANCE: Oro-facial dyskinesia are stereotyped movements, consisting of smacking and pursing of the lips, lateral deviation and protrusion of the tongue, and occasionally lateral deviation and protrusion of the jaw. Oro-facial dyskinesia rarely occur with Huntington's disease, acquired hepatocerebral degeneration, or other choreatic disorders. Spontaneous oro-facial dyskinesias occur in the elderly and had been said to result from edentulousness. It is important to clarify the pathophysiology of senile oro-facial dyskinesia for the prevention and proper treatment. I have had a doubt on the current concept that edentulism is the main etiologic factor of senile oro-facial dyskinesia. Through the clinical experience, I have had an impression that edentulism might not be the primary underlying cause of senile oro-facial dyskinesia. CASE AND METHODS: I have recently experienced four cases of senile oro-facial dyskinesia. There were no history of being exposed to neuroleptics. I tried to clarify the role of edentulism in senile oro-facial dyskinesia through clinical observations, electrophysiologic studies, and pharmacologic trials. CONCLUSION: Two patients said that wearing of denture might be responsible for the development of oro-facial dyskinesia. EMG studies with some procedures showed somewhat consistent results between two patients who were tested. EMG activities were increased by wearing of denture and decreased by touching on the perioral area with examiner's hand. Furthermore two patients who were medicated with dopamine receptor blocker showed marked clinical improvements. These results suggested that senile degenerative changes of central nervous systems might be the primary cause of senile oro-facial dyskinesia.