ABSTRACT
ObjectiveTo explore the role of structural MRI in the diagnosis of spinocerebellar ataxia type 3 （SCA3） and further evaluate its correlation with disease severity and disease duration. MethodsWe prospectively enrolled 81 genetically diagnosed SCA3 patients ［59 symptomatic （sym-SCA3） and 22 pre-symptomatic （pre-SCA3）］ and 35 age- and sex-matched healthy controls （HCs）. MRI structural images （3D T1 MPRAGE） and clinical data of all subjects were collected. Three observers with different radiological experience measured the width of the superior， middle and inferior cerebellar peduncle （SCP， MCP and ICP）， the anterior-posterior diameters of the pons and spinal cord at the levels of the foramen magnum and upper edge of the 3rd-5th cervical vertebra. One observer performed the measurements again 2 months later to assess for the intra- and inter-observer reliability， respectively. One-way ANOVA， rank-sum test， ROC curve and Random Forest were used to evaluate the diagnostic value of the above metrics for SCA3， and the correlation between the metrics and clinical variables was analyzed. ResultsNot depending on the radiological experience， the metrics based on morphological MRI showed high intra- and inter-observer reliability， among which bilateral superior and middle cerebellar peduncles performed best. The diameters of bilateral SCP， MCP， ICP， pons and spinal cord （except spinal cord at the level of the upper edge of the 5th cervical vertebra） decreased successively in HCs， pre-SCA3 and sym-SCA3 with a statistical difference （P<0.017）. ROC analysis revealed that the left MCP had the highest diagnostic value for pre-SCA3 （AUC=0.911）， with sensitivity， specificity and a cut-off value of 85.7%， 95.5% and 10.15 mm， respectively. In contrast， the right SCP had the highest diagnostic value for sym-SCA3 （AUC=0.999）， with sensitivity， specificity and a cut-off value of 100%， 98.3% and 2.62 mm， respectively. The Random Forest model based on the above metrics also had high diagnostic efficiency （AUC= 0.970， specificity=93.1%）， and the left MCP contributed the most. Correlation analysis showed that the above metrics had a significantly or moderately negative correlation with the Scale for the Assessment and Rating of Ataxia （SARA） and disease duration （P<0.05）. ConclusionNot depending on radiological experience， measurements of brain structure based on morphological MRI are reliable， which can help diagnose SCA3 and predict disease severity and duration. The left MCP and the right SCP perform best for predicting pre-SCA3 and sym-SCA3， respectively. Therefore， the structural MRI is recommended for assisting the clinical diagnosis of SCA3.
ABSTRACT
Objective To explore the differences of the global efficiency of the brain structural networks between the male paranoid schizophrenia and male healthy and its relationship with the psychotic symptoms of the schizophrenia.Methods The diffusion tensor imaging data were obtained from 27 male paranoid schizophrenia patients and 28 male healthy controls.The whole cerebral cortex was parcellated into 90 regions by the anatomical label map.Tractography was performed in the whole cerebral cortex of each subject to reconstruct white matter tracts of the brain using fiber assignment by continuous tracking(FACT) algorithm.And then the brain structural binary networks were constructed using the complex network theory.The average global efficiency of the brain network and the global efficiency of the nodes of both groups were examined by two sample t-test and its relationship with the psychotic symptoms in the male paranoid schizophrenia was explored by the correlation analysis.Results Compared with control group,the average global efficiency of the brain network of the patients decreased significantly (7.87±0.56,8.17±0.56,P=0.005),and the global efficiency of the nodes in the brain network of the patient decreased significantly in the left superior frontal gyrus (orbital part) (P=0.00025),the left superior parietal gyrus (P=0.00011),the left cuneus (P=0.00012) and the left putamen (P=0.00032),all survived FDR correction.Significant negative correlation was found between the global efficiency of the left putamen and the total scores (r=-0.43,P=0.03),the positive scores (r=-0.41,P=0.03) and the cognitive scores (r=-0.40,P=0.04) of PANSS.Conclusion The decreased global efficiency of the left frontal,parietal and occipital lobes and the subcortical structures lead to the occurrence of schizophrenia.And the reduced efficiency of the subcortical structures is associated with the positive symptoms and the abnormal cognitive function of the patients.
ABSTRACT
Objective To investigate the small-worldness and the betweenness centrality of the nodes in the brain structural networks and its relationship with the course and the central role of the brain regions in the transmission of information across the whole brain in depression.Methods The diffusion tensor imaging data were obtained from 27 depression patients and 33 healthy controls.The brain structural networks were constructed using the complex network theory.Results The brain structural networks had small-world properties in both groups.When compared with the healthy,the betweenness centrality of the nodes of the networks in depression significantly decreased in right superior frontal gyms (orbital part) (P=0.00035,region survived critical FDR threshold for multiple comparisons),and left putamen (P=0.00054,region survived critical FDR threshold for multiple comparisons).Significant negative correlation was found between the betweenness centrality of left hippocampus and the course in the depression(r=0.50,P=0.016).Conclusion Both of the brain structural networks in depression patients and normal people have the property of small-worldness.But the central role of orbit frontal cortex and putamen in the transmission of information across the whole brain is declined,and the betweenness centrality of hippocampus is negatively related with the course in the depression.
ABSTRACT
Objective To explore the differences of the degree and distribution of hub regions of the brain structural networks between the schizophrenia and healthy and then analysis the importance of brain regions in the information transmission in across the whole brain.Methods The diffusion tensor imaging data were obtained from 22 schizophrenia patients and 24 healthy controls.The whole cerebral cortex was parcellated into 90 regions by the anatonical label map.Tractography was performed in the whole cerebral cortex of each subject to reconstruct white matter tracts of the brain using the fiber assignment by continuous tracking (FACT) algorithm.And then the brain structural binary networks were constructed using the complex network theory.The average degree of the network and the degree of the nodes in the network between the brain structural networks of both groups were examined by two sample t-tests.Results The average degree of the brain structural network in the patient group (7.82±0.56) decreased significantly when compared with the control group (8.17 ±0.56; P=0.04).The degree of the nodes in the brain structural network of the patient group (the left hippocampus:11.41 ± 1.84; the left parahippocampal gyrus:6.41± 1.33 ; the left calcarine fissure:11.50±2.97 ; the left fusiform gyrus:8.27± 1.83) decreased significantly when compared with the control group (14.43±2.26; 8.54±2.15; 14.79±2.80; 10.25± 1.36; all P＜0.01,survived critical FDR threshold for multiple comparisons).And the distribution of the hub regions in the temporal and occipital lobes of the patient group was difference from that of the control group.Conclusion The importance of the hippocampus and the brain regions in the occipital lobe is decrease for the information transmission across the whole brain.The damage of the topological properties of these brain regions maybe related to the disorder of the transmission and integration of information in the brain of the schizophrenia.
ABSTRACT
Objective To explore the differences of the connectivity strength,the clustering coefficient and the local efficiency of the nodes in the brain structural networks in the depression and healthy subjects and then analyze the mode of the local connections of the brain regions and their local efficiency of the transmission of information and their relationship with the severity of the disease in the depression.Methods The Diffusion Tensor Imaging data were obtained from 24 depression patients and 25 healthy controls.The whole cerebral cortex was parcellated into 90 regions by the anatomical label map.Tractography was performed in the whole cerebral cortex of each subject to reconstruct white matter tracts of the brain using the fiber assignment by continuous tracking (FACT) algorithm.And then the brain structural networks were constructed using the complex network theory.The local topological properties of the brain structural networks of the depression and healthy were examined by two sample t-test.Results The local efficiency of the nodes of the networks in depression decreased significantly (the left middle frontal gyrus (orbital part):0.64±0.30,the left hippocampus:0.57±0.07,the right parahippocampal gyrus:0.50±0.15) compared with the healthy (0.88±0.10,0.64±0.06,0.66±0.13 respectively,P=0.00098,0.00039,0.00017,survived critical FDR threshold for multiple comparisons) ; and the clustering coefficient of the nodes of the networks in depression (the left middle frontal gyrus (orbital part):0.14±0.07) decreased significantly when compared with the healthy (0.22±0.06,P=0.000030,survived critical FDR threshold for multiple comparisons).Significant negative correlation was found between the local efficiency of the left middle frontal gyrus (orbital part) and the total scores of HAMD-17 in the depression (r=-0.48,P=0.02).Conclusion The degree of the localization and the local efficiency of the information transmission of the frontal lobe are decreased.The local efficiency in the information transmission in the hippocampal is also decreased.And the local efficiency of the frontal lobe is negatively related with the severity of the disease in the depression.
ABSTRACT
Objective To explore the differences in the strength of the nodes in the brain white matter weighted networks between the male patients with paranoid schizophrenia and male healthy controls, and to analysis the integrity of the white matter fiber tracts that connected to the different brain regions and its relationship with the course of disease. Methods Diffusion tensor imaging (DTI) data were obtained from 25 male patients with paranoid schizophrenia and 26 male healthy controls. The whole brain was parcellated into 90 regions by using the anatomical label map. Tractography was performed in the whole brain of each subject to reconstruct white matter tracts using the FACT algorithm. The brain white matter weighted networks were then constructed using the complex network theory. Results The strength of the nodes in the networks of schizophrenia significantly decreased in the right thalamus (P=0.03, corrected) and the right hes?chl gyrus (P=0.04, corrected). Negative correlation was found between the strength of the right thalamus and the course of disease (r=-0.45, P=0.03). Conclusion The integrity of the white matter fiber tracts connected to the thalamus and tem?poral lobes in the male paranoid schizophrenia is impaired. The lesion of fiber tracts connected to the thalamus is related with the course of disease.
ABSTRACT
BACKGROUND AND PURPOSE: Cardiovascular risk factors are considered to also be risk factors for dementia. Recent studies have shown that the prevalence of cognitive dysfunction is high in patients with cardiac diseases. However, few studies have investigated the influence of cardiac function on cognition and brain structural changes in dementia. The aims of this study were to determine the relationship between cardiac and cognitive function, and to characterize any structural changes in the brain that could be caused by cardiac function in patients with dementia. METHODS: Dementia patients (n=93) were recruited prospectively with checking for the presence of vascular risk factors such as hypertension. Cognitive function was measured by the Mini-Mental State Examination, modified Mini-Mental State test, and Korean version of the Dementia Rating Scale. Brain magnetic resonance imaging was conducted to evaluate the cerebral white-matter changes (WMC), ventricular dilation, and cortical and hippocampal atrophy. Cardiac function was evaluated using two-dimensional echocardiography. We divided the patients into two groups according to the presence (+) or absence (-) of WMC. RESULTS: In the entire cohort, the size of the left atrium (LA) was positively correlated with the degree of WMC, irrespective of age (p<0.05). The LA was larger in the WMC (+) group (n=42) than in the WMC (-) group. General cognitive function was significantly lower in the WMC (+) group than in the WMC (-) group. Subjects with an enlarged LA tended to exhibit lower cognitive function and more-severe cerebral WMC. CONCLUSIONS: Cardiac dysfunction represented by LA enlargement could be related to cognitive decline and WMC of the brain resulting from impairment of the cerebral hemodynamic process in dementia.
Subject(s)
Humans , Atrophy , Brain , Cognition , Cohort Studies , Dementia , Echocardiography , Heart Atria , Heart Diseases , Hemodynamics , Hypertension , Magnetic Resonance Imaging , Prevalence , Prospective Studies , Risk FactorsABSTRACT
The brain structural imaging changes in patients with post-traumatic stress disorders (PTSD) and the related research progress are reviewed. It is elucidated that the volume decrease and the density reductions of gray and white matters in PTSD patients are mainly manifested as the imaging changes of the hippocampus, callus, and anterior cingulate cortex (ACC). The imaging change of callus is characteristic in PTSD patients. The image structure analyses of the white matter and gray matter are the current frontiers and strategic trends of PTSD-related research. Meanwhile, it is pointed out that the relationship between PTSD and brain structure imaging is a problem needs to be urgently solved.