The role of striatal dopamine D2 receptors in the occurrence of extrapyramidal side effects: iodine-123-iodobenzamide single photon emission computed tomography study.

Levels above 75% of striatal dopamine 2 receptor occupancy (D2RO) have been associated with extrapyramidal symptoms (EPS). The aim of the present study is to investigate the relationship between D2RO and EPS in a sample of psychotic patients in current treatment with both typical and atypical antipsychotics. Brain iodine-123-iodobenzamide single photon emission computed tomography ((123)I-IBZM SPECT) was performed in 81 patients taking stable doses of haloperidol, risperidone, olanzapine, quetiapine, clozapine or ziprasidone.