Peripheral Inflammation is Associated with brain SPECT Perfusion Changes in Schizophrenia

Abstract Purpose. Peripheral inflammation is frequent in schizophrenia, and plays a major role in pathophysiology, prognosis, and persistence of psychotic symptomatology under treatment. Aim. To determine the correlation between peripheral inflammation and brain SPECT perfusion in stabilized antipsychotic-treated outpatients with schizophrenia, and to determine whether such perfusion changes are correlated to persistent symptoms. Methods. Highly sensitive C-reactive protein blood level (hs-CRP) and brain SPECT perfusion were assessed in 137 stabilized outpatients with schizophrenia. Whole-brain voxel-based associations were searched with SPM between SPECT perfusion and hs-CRP (correlation analysis to quantitative levels and between-group analysis according to a threshold of 3mg/L). The identified clusters were secondarily correlated with clinical symptoms.Results. After adjustment for age, sex, educational level, illness duration, antidepressant, chlorpromazine equivalent dose, tobacco smoking and obesity, a negative correlation was found between hs-CRP level and the perfusion of 4 brain areas: the right inferior frontal gyrus, the right middle/superior temporal gyrus, the left superior parietal lobe and the right postcentral/transverse temporal gyrus (p-voxel 80, uncorrected). An increased perfusion of the left amygdala was found in patients with hs-CRP ≥ 3 mg/L compared to those with hs-CRP level < 3mg/L. A negative correlation was found between perfusion of the right inferior frontal gyrus and the persistence of positive, negative and excitement symptoms under antipsychotic treatment. Conclusion. In stabilized patients with schizophrenia, peripheral inflammation is associated with brain perfusion changes that are correlated with the persistence of psychotic symptomatology.