Abstract:
Cerebral glucose metabolic rates were determined in normal control
subjects (n 3D 26) and schizophrenic patients with tardive dyskinesia
(n 3D 14). Globus pallidus and primary motor cortex (precentral gyrus)
metabolic values divided by those of the cerebral hemispheres were
significantly increased in the patient group. A similar metabolic
pattern has not been reported for schizophrenic patients without tardive
dyskinesia, and the abnormalities were demonstrated despite the normal
appearance of the basal ganglia on X-ray CT. The findings differed
markedly from the reduced metabolic rates of the basal ganglia
previously identified in other choreiform disorders, including
Huntington's and Wilson's diseases. The findings suggest that tardive
dyskinesia is characterized by increased pallidal synaptic activity
resulting from either altered striatopallidal input or increased
pallidal interneuron firing