Cerebral perfusion correlates of negative symptomatology and parkinsonism in a sample of treatment-refractory schizophrenics: an exploratory 99mTc-HMPAO SPET study.

There is a well recognized clinical overlap between primary and secondary neuroleptic negative symptoms in schizophrenia, but their cerebral substrates are probably different. The study of these substrates could contribute to a better understanding and management of these syndromes. In the present work, the cerebral perfusion correlates, as an indirect measure of the underlying neuronal function, of negative symptoms and parkinsonism were studied with single-photon emission tomography in a group of treatment-refractory paranoid schizophrenic patients. Perfusion ratios with respect to the homolateral cerebellum were compared with a normal database. Correlation coefficients were calculated between perfusion ratios, negative symptoms and parkinsonism scores on exploratory grounds. As a group, the patients showed a bilateral, but predominantly left-sided, hypofrontality and hypotemporality, as well as an increased perfusion in right basal ganglia. Negative symptoms scores negatively correlated with prefrontal perfusion, while parkinsonism positively correlated with the activity of primary motor and sensory cortex. These findings support the existence of different cerebral substrates for primary and secondary negative symptoms in schizophrenia.