Altered asymmetries of resting-state MRI in the left thalamus of first-episode schizophrenia

Background:Schizophrenia(SCZ)is a complex psychiatric disorder associated with widespread alterations in the subcortical brain structure.Hemispheric asymmetries are a fundamental organizational principle of the human brain and relate to human psychological and behavioral characteristics.We aimed to explore the state of thalamic lateralization of SCZ.Methods:We used voxel-based morphometry(VBM)analysis,whole-brain analysis of low-frequency fluctuations(ALFF),fractional amplitude of low-frequency fluctuations(fALFF),and resting-state seed-based functional connectivity(FC)analysis to investigate brain structural and functional deficits in SCZ.Also,we applied Pearson’’s correlation analysis to validate the correlation between Positive and Negative Symptom Scale(PANSS)scores and them.Results:Compared with healthy controls,SCZ showed increased gray matter volume(GMV)of the left thalamus(t=2.214,p=0.029),which positively correlated with general psychosis(r=0.423,p=0.010).SCZ also showed increased ALFF in the putamen,the caudate nucleus,the thalamus,fALFF in the nucleus accumbens(NAc),and the caudate nucleus,and decreased fALFF in the precuneus.The left thalamus showed significantly weaker resting-state FC with the amygdala and insula in SCZ.PANSS negative symptom scores were negatively correlated with the resting-state FC between the thalamus and the insula(r=-0.414,p=0.025).Conclusions:Collectively,these results suggest the possibility of aberrant laterality in the left thalamus and its FC with other related brain regions involved in the limbic system.