Background: The pathological basis of tardive dyskinesia is unknown. Although its clinical features implicate the basal ganglia, imaging studies have not found clear evidence that it is associated with volume changes in these or other brain structures.
Aims: To determine, using voxel-based structural imaging, whether there are regions of grey matter volume change in people with schizophrenia who also have tardive dyskinesia compared with those without tardive dyskinesia.
Method: A total of 81 people with chronic schizophrenia, 32 with tardive dyskinesia and 49 without, were examined using magnetic resonance imaging (MRI) and whole-brain, optimised voxel-based morphometry. A comparison group of 61 healthy controls was also examined.
Results: Compared with those without tardive dyskinesia, patients with tardive dyskinesia showed a pattern of volume reductions in predominantly subcortical regions, including the basal ganglia and the thalamus. Within the basal ganglia, volume reductions were seen in the caudate nucleus, to a lesser extent in the putamen, and only marginally in the globus pallidus. The patients with tardive dyskinesia, but not those without, showed significant volume reductions in the basal ganglia compared with the healthy controls but both groups had smaller volumes than controls in other affected areas.
Conclusions: The pathological process or processes that underlie the development of tardive dyskinesia are not just neurochemical in nature, but affect brain structure.