Chemical and Structural Changes in the Brain in Patients with Movement Disorder

Neurochemical indices of dopaminergic function were assessed in basal ganglia of post-mortem brains of control subjects and schizophrenic patients who had been rated in life for the presence of movement disorder and neuroleptic intake. In schizophrenics who had been treated chronically with high doses of neuroleptics, concentrations of dopamine D2 receptors were significantly increased above controls, whereas dopamine D1 receptors and dopamine metabolism were unchanged. Increased D2 receptors were also observed in basal ganglia of drug-free patients. Concentrations of dopamine D1 and D2 receptors in schizophrenics with movement disorder were not significantly different to those in schizophrenics without movement disorder. Moreover, no relationship was found between dopamine receptor levels and the severity of movement disorder. Concentrations of the dopamine metabolite homovanillic acid were increased in the putamen and nucleus accumbens in a small number of patients with movement disorder compared with controls or patients without movement disorder. No changes were observed in markers of cholinergic and GABA-containing neurones. The present findings are not consistent with a “dopamine receptor hypersensitivity” concept of movement disorder in schizophrenia.