Magnetic Resonance Study Of Primary Visual Network In Patients With Schizophrenia

Schizophrenia is a complex and pathologically diverse mental disorder.At present,there is no definite theory about the pathogenesis of schizophrenia.Symptoms of schizophrenia can be mainly divided into three categories: positive symptoms,negative symptoms and cognitive impairment.At present,there is no unified and effective treatment plan for schizophrenia.This has a huge and profound impact on patients and society.The primary visual network of schizophrenics is impaired,which is probably one of the important causes of the symptoms of schizophrenia.In recent years,magnetic resonance imaging,with its high spatial resolution and non-invasive advantages,has provided great help to explore the pathophysiological mechanism of schizophrenia.This study focused on the functional and structural laterality of the primary visual cortex in patients with schizophrenia.At the same time,combined with task-state visual stimulation,the functional connection differences between and within the primary visual network of schizophrenic patients were studied.This article is mainly divided into the following two aspects.In the first part,combining functional and structural magnetic resonance data,we studied the laterality of the visual cortex in patients with schizophrenia.We calculated the laterality of functional connection density,volume,fractional anisotropy(FA)and mean dispersion rate(MD)of primary visual cortex and basal ganglia system respectively.The results showed that the increased left lateralities of volume were observed in fusiform gyrus,striatum and the decreased left laterality in thalamus of schizophrenia.We also found that the specific balance of schizophrenia changed the laterality of the MD in the middld of occipital gyrus and thalamus.At the same time,the decreased left lateralities of FA were observed in the middld of occipital gyrus.Additionally,we observed a correlation between PANSS-positive value and the laterality index of the middld of occipital gyrus and thalamus.However,there is no difference in functional laterality.These results indicate abnormal asymmetry in the structure of the primary visual cortex and basal ganglia system of schizophrenia.In the second part,we focused on the dysfunction of the primary visual network in schizophrenia.We first calculated the activation of the primary visual network under different conditions by steady-state visual evoked potential and grating stimulation.Combined with the two tasks,the differences in functional connectivity within and between primary visual networks in schizophrenia were explored.The results showed that under the steady-state visual evoked potential stimulation,the activation of the lingual gyrus in schizophrenia was significantly higher.At the same time,the repeated measurement variance interaction effect of grating stimulation showed that the main activation difference of the two groups were distributed in the superior parietal gyrus and the left precentral gyrus.Among the 11 network components selected by ICA,we found that there were significant differences in the functional connection strength of the right calcarine in the primary visual network,the left caudatus nucleus and the left putamen in the basal ganglia network and the left insula in the salience network between the two groups under different task stimulation.At the same time,functional connections between networks were found that,under grating stimulation,functional connections between basal ganglia network and cerebellum network were decreased,and sensorimotor network and cerebellum network were increased.This shows that schizophrenia visual network disorders,not only is the primary visual network functional connectivity abnormalities,but also may be abnormal functional connectivity between the networks.In summary,this study explored the primary visual network abnormalities in schizophrenia from two aspects: structure and function.The results showed that the primary visual cortex and basal ganglia system were abnormally asymmetrical.At the same time,the functional connections within and between the primary visual networks of schizophrenics were different.We hope that this study can increase the understanding of the primary visual network of schizophrenia and provide new evidence for the study of the pathophysiology of schizophrenia.