In Southern India, a group of researchers had found that spontaneous dyskinesia is common in chronically ill patients who had never been treated for schizophrenia. More recently, they reported that they have found brain structure changes in these patients via magnetic resonance imaging. In contrast to patients without dyskinesia, the left lenticular nucleus is larger in patients with dyskinesia and, compared with controls, the right lateral ventricle to hemisphere ratio is larger in patients without dyskinesia. Furthermore, in controls, increasing age was associated with decreased basal ganglia volume. These findings indicate there is a subgroup of patients with schizophrenia and dyskinesia striatal pathology.
Reference: McCreadie RG, Thara R, Padmavati R et al. (2002), Structural brain differences between never-treated patients with schizophrenia, with and without dyskinesia, and normal control subjects: a magnetic resonance imaging study. Arch Gen Psychiatry 59(4):332-336.