Edentulousness and neuroleptic-induced neck and trunk dyskinesia.

Edentulousness, by disrupting trigeminal propioceptive input from the oral cavity to the basal ganglia, may increase the risk for neuroleptic-induced orofacial dyskinesia. Since lesions of the globus pallidus alter trigeminal sensory-induced reflexive neck muscle activity in rats and the putamen-caudate complex regulates vestibular and propioceptive mechanisms, edentulousness could facilitate also the expression of neuroleptic-induced neck and trunk dyskinesias. In a sample of 131 neuroleptic-treated chronic schizophrenic patients, we found that edentulous patients exhibited significantly more neck and trunk dyskinesias as compared to nonedentulous patients (p less than 005). By contrast, dyskinesias of the face, tongue, and extremities did not differ between the two cohorts of patients. Our findings imply that edentulousness may increase the risk of neck and trunk dyskinesias and highlight the importance of the dental status in tardive dyskinesia.