Brain Structure And Function In Schizophrenia: A Mutimodal MRI Study

Schizophrenia,mostly in young adults,is a high disabling mental disorder.The patient with unexplained hallucinations,delusions,and other major symptoms,accompanied by a variety of cognitive dysfunction including the thoughts,emotions,feelings,and behaviors.The abnormality of brain structure and function and the effect of drug treatment in schizophrenia patients are still important issues to be solved.In recent years,magnetic resonance imaging(magnetic resonance imaging,MRI)as a non-invasive means of research,is currently an important tool for the study of various types of mental illness,which provides a new sight to the neuropathological mechanisms of mental disorders.The hippocampus plays a key role in memory,affective triggering,and spatial orientation,and previous studies have found that the significant association between the abnormal hippocampal volume and the clinical symptoms in schizophrenic patients.By means of the volumetric analysis,we investigated the abnormal hippocampal volume could indirectly affect the association between the patients' symptoms and verbal memory.When controlling for the total brain volume,left hippocampal volumes in patients was abnormal and significantly lower than those in HCs.Meanwhile,the relationships between the left hippocampal volume and age are different in patients with schizophrenic patients and HCs,respectively.The left hippocampal volume in patients is negatively correlated with the age,while the left hippocampal volume in HCs is positively correlated with age.We also found the left hippocampal volume in schizophrenic patients has become a mediator of the relationship between negative symptoms and verbal memory.These findings indicate the left hippocampal volume plays an important role in the pathological mechanism in schizophrenic patients.In addition,some studies have reported abnormal temporal complexity of blood oxygen level dependent(BOLD)signal in schizophrenic patients.The multiscale entropy analysis was used to detect the effects of drug therapy with risperidone on the BOLD signal in schizophrenic patients.It was found that the effects of drugs therapy on the temporal complexity of several brain regions were different among brain regions in schizophrenic patients.After 8 weeks of risperidone treatment,the complexity in schizophrenia after treatment was significantly higher than those of before treatment among 6 brain regions.The six brain regions were left middle ventrolateral frontal gyrus,left superior temporal gyrus,right inferior temporal gyrus?right posterior superior temporal sulcus,right precuneus,left thalamus,while the other four brain regions had a significant low temporal complexity relative to pretreatment.The four brain regions were left middle dorsal frontal gyrus,right postcentral gyrus,left cingulate gyrus,right striatum.These findings show that the drug has an impact on the temporal complexity of the brain of patients with schizophrenia.This may indicate that the temporal complexity of the schizophrenia brain could become a neuroimaging biomarker for the diagnosis and treatment of the disease.In summary,on the one hand,the first study,from the perspective of hippocampal morphology,explores that the influence on the brain structure in adolescent was caused by the schizophrenia,and then discovers the relationship among structure,cognition and symptoms,reflecting that the left hippocampus plays an important role in pathological mechanism of schizophrenia;On the other hand,the second study explores that the effects on the brain temporal complexity with drugs treatment,which shows the effect of the drugs on the nervous system of the brain and perhaps provides an effective scientific basis for clinical diagnosis and treatment.