Seasonal Effects Research On Patients With Schizophrenia Based On Brain Resting-State Functional Magnetic Resonance Imaging

Schizophrenia is a complex mental disease,often occurring in young adults,with behavior,emotion,thinking and other aspects of disorder as well as mental activity is not coherent as its remarkable characteristics.Because of its complexity,pathogenesis,treatment,and prevention of schizophrenia are always the focus of psychiatric research.Resting state functional magnetic resonance imaging(rs-f MRI)is an effective means to explore the pathology of schizophrenia.Schizophrenics have extensive brain abnormal structural and functional connectivity,which are related to the clinical symptoms,also considered to be the pathological basis of the patient’s thought,emotion and behavior integration abnormalities,further leading to the core abnormalities of schizophrenia.Studies have shown that the onset of schizophrenia is influenced by season,and it is not clear whether seasonal changes are related to abnormal brain function and neuropathology of schizophrenia.In this study,we used functional magnetic resonance(f MRI)technique to characterize the brain dynamic function by blood oxygen metabolism variability(BOMV).We investigated seasonal changes and frequency dependence of brain dynamic function in healthy people,and abnormal seasonal changes of brain blood oxygen metabolism variability in schizophrenics.First of all,using magnetic resonance technology,the head magnetic resonance data of 29 healthy people were collected in summer and winter.After analyzing seasonal changes of BOMV in typical band(0.01-0.08 Hz),this study found BOMV in striatum in summer was significantly higher than in winter.Then the bands were subdivided to explore seasonal(summer and winter)and frequency(slow-5 band: 0.01-0.027 Hz and slow-4 band: 0.027-0.073 Hz)effects of BOMV on healthy people using repeated measures analysis of variance.We found BOMV in summer was significantly higher in prefrontal and putamen regions than in winter.In frontal and precuneus regions,BOMV was higher in slow-5 than in slow-4 bands,while in the subcortical region was on the opposite.In addition,the BOMV in slow-5 bands of prefrontal BOMV was higher than that in slow-4 bands in summer and winter,while in slow-5 bands,right putamen BOMV was lower than that in slow-4 bands.Moreover,the BOMV of prefrontal and right putamen was slow-5 bands-specifically higher in summer than that in winter.This study showed that the blood oxygen metabolism variability fluctuated annually,and the fluctuation of BOLD signal in striatum was stronger in summer than in winter,brain dynamic function in the subcortical area was given priority to high-frequency signal,and the cortex area was given priority to low-frequency signal.The decreased activity of striatal dopaminergic system in winter may be due to the decrease of low frequency signals in dynamic functional characteristics.Further,we incorporated in 51 patients with schizophrenia(SZ)and 72 healthy subjects,including 32 SZ in spring-summer group,19 SZ in fall-winter group,27 healthy subjects in spring-summer group and 45 healthy subjects in fall-winter group.We used magnetic resonance technology to explore schizophrenia patients abnormal BOMV and its seasonal changes.By studying the BOMV of SZ and healthy people in different seasons,we found that SZ had lower BOMV in primary sensorimotor and visual networks,and higher BOMV in caudate and thalamus than healthy people.The BOMV of right putamen was higher in all subjects in spring-summer group than in fall-winter group.In addition,we found that there were significant seasonal and group interaction effects of BOMV in the left hippocampus,right putamen,right thalamus,and right pallidum.Specifically,in fall-winter,the levels of BOMV in the left hippocampus,right pallidum,right thalamus and right putamen were significantly higher in SZ than those in healthy subjects.In spring-summer,SZ had significantly lower levels of BOMV in right thalamus and right putamen than healthy individuals.Function-function coupling studies found that the correlation of hippocampus-pallidum BOMV was lower in SZ than in healthy individuals in fall-winter.Function-structure coupling studies showed that the correlation between BOMV of hippocampal and volume decreased in spring-summer in SZ.In addition,there was a significant negative correlation between BOMV in right thalamus and positive symptom of PANSS in spring-summer SZ.These results suggested that there was indeed a dopamine and biorhythm interaction,and striatum function’s seasonal changes in SZ may be related to changes in dopaminergic system function,and these seasonal specific changes were likely to be the driving factors of pathological changes in schizophrenia.