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Stephen M Lawrie - One of the best experts on this subject based on the ideXlab platform.
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white matter abnormalities in bipolar disorder and schizophrenia detected using diffusion tensor magnetic resonance imaging
Bipolar Disorders, 2009Co-Authors: Jessika E Sussmann, Dominic Job, Mark E Bastin, Eve C Johnstone, Susana Munoz Maniega, Katherine G S Lymer, James Mckirdy, William T J Moorhead, Jeremy Hall, Stephen M LawrieAbstract:OBJECTIVES: Strong qualitative and quantitative evidence exists of white matter abnormalities in both schizophrenia and bipolar disorder (BD). Diffusion tensor imaging (DTI) studies suggest altered connectivity in both disorders. We aim to address the diagnostic specificity of white matter abnormalities in these disorders. METHODS: DTI was used to assess white matter integrity in clinically stable patients with familial BD (n = 42) and familial schizophrenia (n = 28), and in controls (n = 38). Differences in fractional anisotropy (FA) were measured using voxel-based morphometry and automated region of interest analysis. RESULTS: Reduced FA was found in the anterior limb of the internal capsule (ALIC), anterior thalamic radiation (ATR), and in the region of the Uncinate Fasciculus in patients with BD and those with schizophrenia compared with controls. A direct comparison between patient groups found no significant differences in these regions. None of the findings were associated with psychotropic medication. CONCLUSIONS: Reduced integrity of the ALIC, Uncinate Fasciculus, and ATR regions is common to both schizophrenia and BD. These results imply an overlap in white matter pathology, possibly relating to risk factors common to both disorders.
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structural disconnectivity in schizophrenia a diffusion tensor magnetic resonance imaging study
British Journal of Psychiatry, 2003Co-Authors: J Burns, Dominic Job, Mark E Bastin, Heather C Whalley, Tom Macgillivray, Eve C Johnstone, Stephen M LawrieAbstract:Background There is growing evidence that schizophrenia is a disorder of cortical connectivity. Specifically, frontotemporal and frontoparietal connections are thought to be functionally impaired. Diffusion tensor magnetic resonance imaging (DT—MRI) is a technique that has the potential to demonstrate structural disconnectivity in schizophrenia. Aims To investigate the structural integrity of frontotemporal and frontoparietal white matter tracts in schizophrenia. Method Thirty patients with DSM—IV schizophrenia and thirty matched control subjects underwent DT—MRI and structural MRI. Fractional anisotropy — an index of the integrity of white matter tracts — was determined in the Uncinate Fasciculus, the anterior cingulum and the arcuate Fasciculus and analysed using voxel-based morphometry. Results There was reduced fractional anisotropy in the left Uncinate Fasciculus and left arcuate Fasciculus in patients with schizophrenia compared with controls. Conclusions The findings of reduced white matter tract integrity in the left Uncinate Fasciculus and left arcuate Fasciculus suggest that there is frontotemporal and frontoparietal structural disconnectivity in schizophrenia.
Marek Kubicki - One of the best experts on this subject based on the ideXlab platform.
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Childhood adversity associated with white matter alteration in the corpus callosum, corona radiata, and Uncinate Fasciculus of psychiatrically healthy adults.
Brain Imaging and Behavior, 2017Co-Authors: Simon Mccarthy-jones, Lena K. L. Oestreich, Amanda E. Lyall, Zora Kikinis, Dominick T. Newell, Peter Savadjiev, Martha E. Shenton, Marek Kubicki, Ofer Pasternak, Thomas J. WhitfordAbstract:Diffusion tensor imaging studies report childhood adversity (CA) is associated with reduced fractional anisotropy (FA) in multiple white matter tracts in adults. Reduced FA may result from changes in tissue, suggesting myelin/axonal damage, and/or from increased levels of extracellular free-water, suggesting atrophy or neuroinflammation. Free-water imaging can separately identify FA in tissue (FAT) and the fractional volume of free-water (FW). We tested whether CA was associated with altered FA, FAT, and FW in seven white matter regions of interest (ROI), in which FA changes had been previously linked to CA (corona radiata, corpus callosum, fornix, cingulum bundle: hippocampal projection, inferior fronto-occipital Fasciculus, superior longitudinal Fasciculus, Uncinate Fasciculus). Tract-based spatial statistics were performed in 147 psychiatrically healthy adults who had completed a self-report questionnaire on CA primarily stemming from parental maltreatment. ROI were extracted according to the protocol provided by the ENIGMA-DTI working group. Analyses were performed both treating CA as a continuous and a categorical variable. CA was associated with reduced FA in all ROI (although categorical analyses failed to find an association in the fornix). In contrast, CA was only associated with reduced FAT in the corona radiata, corpus callosum, and Uncinate Fasciculus (with the continuous measure of CA finding evidence of a negative relation between CA and FAT in the fornix). There was no association between CA on FW in any ROI. These results provide preliminary evidence that childhood adversity is associated with changes to the microstructure of white matter itself in adulthood. However, these results should be treated with caution until they can be replicated by future studies which address the limitations of the present study.
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Uncinate Fasciculus abnormalities in recent onset schizophrenia and affective psychosis a diffusion tensor imaging study
Schizophrenia Research, 2009Co-Authors: Toshiro Kawashima, Marek Kubicki, Motoaki Nakamura, Carlfredrik Westin, Dean F Salisbury, Robert W Mccarley, Sylvain Bouix, Martha E. ShentonAbstract:Two of the most frequently investigated regions in diffusion tensor imaging studies in chronic schizophrenia are the Uncinate Fasciculus (UF) and cingulum bundle (CB). The purpose of the present study was to determine whether UF and CB white matter integrity were altered at the early stage of illness and specific to schizophrenia. Fifteen schizophrenia subjects and 15 affective psychosis within 4 years of first hospitalization (12 patients with schizophrenia and 12 patients with affective psychosis during their first hospitalization), and 15 psychiatrically healthy controls underwent line-scan diffusion tensor imaging. Fractional anisotropy (FA) and mean diffusivity (D(m)) were used to quantify water diffusion, and cross-sectional area was defined with a directional threshold method. Bilaterally reduced FA, but not D(m), was present in the UF of schizophrenia compared with healthy controls. Affective psychosis was intermediate between schizophrenia subjects and healthy controls, but not significantly different from either. For CB, there was no significant group difference for FA or D(m). These findings suggest that UF, but not CB, white matter integrity is altered at the early stage of illness in schizophrenia although it may not be specific to schizophrenia. The CB abnormalities reported in chronic schizophrenia may develop during the later course of the disease.
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the Uncinate Fasciculus and extraversion in schizotypal personality disorder a diffusion tensor imaging study
Schizophrenia Research, 2007Co-Authors: Ronald J Gurrera, Marek Kubicki, Motoaki Nakamura, Chandlee C Dickey, Margaret A Niznikiewicz, Martina M Voglmaier, Larry J SeidmanAbstract:The Uncinate Fasciculus (UF) is the most prominent white matter tract connecting frontal and temporal brain regions, and is altered in schizotypal personality disorder (SPD) (Nakamura et al, 2005). SPD is also associated with elevated neuroticism and reduced extraversion and agreeableness (Gurrera et al, 2005a). Since brain regions connected by the UF play important roles in personality function, we tested the hypothesis that UF white matter integrity and personality dimensions are interrelated in SPD. Eleven neuroleptic-naive men with SPD and eight psychiatrically healthy men were recruited from the community for magnetic resonance studies of SPD (Nakamura et al, 2005). Subjects were included in the present analysis if they also completed a personality questionnaire (NEO Five Factor Inventory: Costa and McCrae, 1992). Fiber tract coherence was measured by fractional anisotropy (FA); a higher FA index indicates greater water diffusion directionality in the fiber tract, since water diffusion is greater inside the axon than across the myelin sheath (i.e., diffusion is “anisotropic”). Line scan diffusion tensor imaging and computational measures were performed as previously described (Kubicki et al, 2002). Multiple linear regression, with right and left FA entered as independent variables, was used to evaluate the relationship between UF integrity and personality measures. Standardized regression coefficients (β) are reported; probabilities are two-tailed. SPD and comparison groups did not differ in mean age (39.2±13.0 vs. 34.2±9.8 years), subject or parental SES, educational level, or full scale IQ. SPD subjects had higher mean Neuroticism (58.7±14.6 vs. 39.0±6.4, t= 3.55, df= 17, p= .002), and lower mean Extraversion (43.6±13.5 vs. 59.7±4.9, t= −3.20, df= 17, p= .005) and Agreeableness (41.8±14.1 vs. 58.1±10.3, t= −2.76, df= 17, p= .013). SPD subjects had significantly lower mean right FA (592.5±40.5 vs. 638.1±42.9, t= −2.37, df= 17, p= .030) and left FA (597.1±43.8 vs. 641.4±42.2, t= −2.21, df= 17, p= .041) (Figure 1A). No differences in mean diffusivity or cross-sectional area were found. FIGURE 1 The Uncinate Fasciculus (UF) and Extraversion in SPD In SPD subjects, FA strongly predicted Extraversion (F[2,8]= 16.02, p= .002), but only on the right side (β= .89, p= .001 vs. β= .02, p= .883). Moreover, FA weakly predicted Agreeableness in SPD subjects (F[2,8]= 4.38, p= .052), again only on the right side (β= .58, p= .048 vs. β= .33, p= .225), and there was also a trend toward right FA predicting Neuroticism (F[2,8]= 4.64, p= .046; β= −.54, p= .061 vs. β= −.40, p= .139). Of note, there were no significant results for comparison subjects. Figure 1B illustrates the relationship between right UF FA and Extraversion. Personality and UF anatomy alterations in SPD resemble those found in schizophrenia (Gurrera et al, 2000; Kubicki et al, 2002), and some clinical features of schizophrenia may reflect fronto-temporal connectivity abnormalities (McGuire and Frith, 1996). Personality changes in schizophrenia may also stem from altered brain function (Gurrera et al, 2005b). The present data suggest that reduced right UF integrity contributes to reduced extraversion in SPD. Interestingly, the UF appears to mediate autonoetic awareness, or awareness of oneself as a continuous entity across time, which is manifested in the ability to re-experience remembered events as part of one’s past (Levine et al, 1998). In unstructured situations, autonoetic awareness supports the formulation of goals and the behavioral oversight needed to attain them (Levine et al, 1998). Thus, individual differences in autonoetic awareness could contribute to variation in human approach-avoidance behaviors, especially in unstructured social situations where individual differences in extraversion are most evident. This study is limited by small sample size. Exclusive reliance on a self-report personality measure is also a potential limitation, though observer-based personality measures are subject to similar biases (Ozer, 1999).
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white matter hemisphere asymmetries in healthy subjects and in schizophrenia a diffusion tensor mri study
NeuroImage, 2004Co-Authors: Haejeong Park, Marek Kubicki, Margaret A Niznikiewicz, Carlfredrik Westin, Stephan E Maier, Melissa Frumin, Ron Kikinis, Aaron H Baer, Ferenc A JoleszAbstract:Hemisphere asymmetry was explored in normal healthy subjects and in patients with schizophrenia using a novel voxel-based tensor analysis applied to fractional anisotropy (FA) of the diffusion tensor. Our voxel-based approach, which requires precise spatial normalization to remove the misalignment of fiber tracts, includes generating a symmetrical group average template of the diffusion tensor by applying nonlinear elastic warping of the demons algorithm. We then normalized all 32 diffusion tensor MRIs from healthy subjects and 23 from schizophrenic subjects to the symmetrical average template. For each brain, six channels of tensor component images and one T2-weighted image were used for registration to match tensor orientation and shape between images. A statistical evaluation of white matter asymmetry was then conducted on the normalized FA images and their flipped images. In controls, we found left-higher-than-right anisotropic asymmetry in the anterior part of the corpus callosum, cingulum bundle, the optic radiation, and the superior cerebellar peduncle, and right-higher-than-left anisotropic asymmetry in the anterior limb of the internal capsule and the anterior limb's prefrontal regions, in the Uncinate Fasciculus, and in the superior longitudinal Fasciculus. In patients, the asymmetry was lower, although still present, in the cingulum bundle and the anterior corpus callosum, and not found in the anterior limb of the internal capsule, the Uncinate Fasciculus, and the superior cerebellar peduncle compared to healthy subjects. These findings of anisotropic asymmetry pattern differences between healthy controls and patients with schizophrenia are likely related to neurodevelopmental abnormalities in schizophrenia.
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Uncinate Fasciculus findings in schizophrenia a magnetic resonance diffusion tensor imaging study
American Journal of Psychiatry, 2002Co-Authors: Marek Kubicki, Carlfredrik Westin, Stephan E Maier, Melissa Frumin, Paul G Nestor, Dean F Salisbury, Ron Kikinis, Ferenc A Jolesz, Robert W Mccarley, Martha E. ShentonAbstract:Objective: Disruptions in connectivity between the frontal and temporal lobes may explain some of the symptoms observed in schizophrenia. Conventional magnetic resonance imaging (MRI) studies, however, have not shown compelling evidence for white matter abnormalities, because white matter fiber tracts cannot be visualized by conventional MRI. Diffusion tensor imaging is a relatively new technique that can detect subtle white matter abnormalities in vivo by assessing the degree to which directionally organized fibers have lost their normal integrity. The first three diffusion tensor imaging studies in schizophrenia showed lower anisotropic diffusion, relative to comparison subjects, in whole-brain white matter, prefrontal and temporal white matter, and the corpus callosum, respectively. Here the authors focus on fiber tracts forming temporal-frontal connections. Method: Anisotropic diffusion was assessed in the Uncinate Fasciculus, the most prominent white matter tract connecting temporal and frontal brain regions, in 15 patients with chronic schizophrenia and 18 normal comparison subjects. A 1.5-T GE Echospeed system was used to acquire 4mm-thick coronal line-scan diffusion tensor images. Maps of the fractional anisotropy were generated to quantify the water diffusion within the Uncinate Fasciculus. Results: Findings revealed a group-byside interaction for fractional anisotropy and for Uncinate Fasciculus area, derived from automatic segmentation. The patients with schizophrenia showed a lack of normal left-greater-than-right asymmetry seen in the comparison subjects. Conclusions: These findings demonstrate the importance of investigating white matter tracts in vivo in schizophrenia and support the hypothesis of a disruption in the normal pattern of connectivity between temporal and frontal brain regions in schizophrenia.
Mark E Bastin - One of the best experts on this subject based on the ideXlab platform.
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trait conscientiousness and the personality meta trait stability are associated with regional white matter microstructure
Social Cognitive and Affective Neuroscience, 2016Co-Authors: Gary J Lewis, Mark E Bastin, Simon R Cox, Tom Booth, Susana Munoz Maniega, Natalie A Royle, Maria Valdes Hernandez, Joanna M Wardlaw, Ian J DearyAbstract:Establishing the neural bases of individual differences in personality has been an enduring topic of interest. However, while a growing literature has sought to characterize grey matter correlates of personality traits, little attention to date has been focused on regional white matter correlates of personality, especially for the personality traits agreeableness, conscientiousness and openness. To rectify this gap in knowledge we used a large sample (n > 550) of older adults who provided data on both personality (International Personality Item Pool) and white matter tract-specific fractional anisotropy (FA) from diffusion tensor MRI. Results indicated that conscientiousness was associated with greater FA in the left Uncinate Fasciculus (β = 0.17, P < 0.001). We also examined links between FA and the personality meta-trait 'stability', which is defined as the common variance underlying agreeableness, conscientiousness, and neuroticism/emotional stability. We observed an association between left Uncinate Fasciculus FA and stability (β = 0.27, P < 0.001), which fully accounted for the link between left Uncinate Fasciculus FA and conscientiousness. In sum, these results provide novel evidence for links between regional white matter microstructure and key traits of human personality, specifically conscientiousness and the meta-trait, stability. Future research is recommended to replicate and address the causal directions of these associations.
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white matter abnormalities in bipolar disorder and schizophrenia detected using diffusion tensor magnetic resonance imaging
Bipolar Disorders, 2009Co-Authors: Jessika E Sussmann, Dominic Job, Mark E Bastin, Eve C Johnstone, Susana Munoz Maniega, Katherine G S Lymer, James Mckirdy, William T J Moorhead, Jeremy Hall, Stephen M LawrieAbstract:OBJECTIVES: Strong qualitative and quantitative evidence exists of white matter abnormalities in both schizophrenia and bipolar disorder (BD). Diffusion tensor imaging (DTI) studies suggest altered connectivity in both disorders. We aim to address the diagnostic specificity of white matter abnormalities in these disorders. METHODS: DTI was used to assess white matter integrity in clinically stable patients with familial BD (n = 42) and familial schizophrenia (n = 28), and in controls (n = 38). Differences in fractional anisotropy (FA) were measured using voxel-based morphometry and automated region of interest analysis. RESULTS: Reduced FA was found in the anterior limb of the internal capsule (ALIC), anterior thalamic radiation (ATR), and in the region of the Uncinate Fasciculus in patients with BD and those with schizophrenia compared with controls. A direct comparison between patient groups found no significant differences in these regions. None of the findings were associated with psychotropic medication. CONCLUSIONS: Reduced integrity of the ALIC, Uncinate Fasciculus, and ATR regions is common to both schizophrenia and BD. These results imply an overlap in white matter pathology, possibly relating to risk factors common to both disorders.
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structural disconnectivity in schizophrenia a diffusion tensor magnetic resonance imaging study
British Journal of Psychiatry, 2003Co-Authors: J Burns, Dominic Job, Mark E Bastin, Heather C Whalley, Tom Macgillivray, Eve C Johnstone, Stephen M LawrieAbstract:Background There is growing evidence that schizophrenia is a disorder of cortical connectivity. Specifically, frontotemporal and frontoparietal connections are thought to be functionally impaired. Diffusion tensor magnetic resonance imaging (DT—MRI) is a technique that has the potential to demonstrate structural disconnectivity in schizophrenia. Aims To investigate the structural integrity of frontotemporal and frontoparietal white matter tracts in schizophrenia. Method Thirty patients with DSM—IV schizophrenia and thirty matched control subjects underwent DT—MRI and structural MRI. Fractional anisotropy — an index of the integrity of white matter tracts — was determined in the Uncinate Fasciculus, the anterior cingulum and the arcuate Fasciculus and analysed using voxel-based morphometry. Results There was reduced fractional anisotropy in the left Uncinate Fasciculus and left arcuate Fasciculus in patients with schizophrenia compared with controls. Conclusions The findings of reduced white matter tract integrity in the left Uncinate Fasciculus and left arcuate Fasciculus suggest that there is frontotemporal and frontoparietal structural disconnectivity in schizophrenia.
Martha E. Shenton - One of the best experts on this subject based on the ideXlab platform.
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Childhood adversity associated with white matter alteration in the corpus callosum, corona radiata, and Uncinate Fasciculus of psychiatrically healthy adults.
Brain Imaging and Behavior, 2017Co-Authors: Simon Mccarthy-jones, Lena K. L. Oestreich, Amanda E. Lyall, Zora Kikinis, Dominick T. Newell, Peter Savadjiev, Martha E. Shenton, Marek Kubicki, Ofer Pasternak, Thomas J. WhitfordAbstract:Diffusion tensor imaging studies report childhood adversity (CA) is associated with reduced fractional anisotropy (FA) in multiple white matter tracts in adults. Reduced FA may result from changes in tissue, suggesting myelin/axonal damage, and/or from increased levels of extracellular free-water, suggesting atrophy or neuroinflammation. Free-water imaging can separately identify FA in tissue (FAT) and the fractional volume of free-water (FW). We tested whether CA was associated with altered FA, FAT, and FW in seven white matter regions of interest (ROI), in which FA changes had been previously linked to CA (corona radiata, corpus callosum, fornix, cingulum bundle: hippocampal projection, inferior fronto-occipital Fasciculus, superior longitudinal Fasciculus, Uncinate Fasciculus). Tract-based spatial statistics were performed in 147 psychiatrically healthy adults who had completed a self-report questionnaire on CA primarily stemming from parental maltreatment. ROI were extracted according to the protocol provided by the ENIGMA-DTI working group. Analyses were performed both treating CA as a continuous and a categorical variable. CA was associated with reduced FA in all ROI (although categorical analyses failed to find an association in the fornix). In contrast, CA was only associated with reduced FAT in the corona radiata, corpus callosum, and Uncinate Fasciculus (with the continuous measure of CA finding evidence of a negative relation between CA and FAT in the fornix). There was no association between CA on FW in any ROI. These results provide preliminary evidence that childhood adversity is associated with changes to the microstructure of white matter itself in adulthood. However, these results should be treated with caution until they can be replicated by future studies which address the limitations of the present study.
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Uncinate Fasciculus abnormalities in recent onset schizophrenia and affective psychosis a diffusion tensor imaging study
Schizophrenia Research, 2009Co-Authors: Toshiro Kawashima, Marek Kubicki, Motoaki Nakamura, Carlfredrik Westin, Dean F Salisbury, Robert W Mccarley, Sylvain Bouix, Martha E. ShentonAbstract:Two of the most frequently investigated regions in diffusion tensor imaging studies in chronic schizophrenia are the Uncinate Fasciculus (UF) and cingulum bundle (CB). The purpose of the present study was to determine whether UF and CB white matter integrity were altered at the early stage of illness and specific to schizophrenia. Fifteen schizophrenia subjects and 15 affective psychosis within 4 years of first hospitalization (12 patients with schizophrenia and 12 patients with affective psychosis during their first hospitalization), and 15 psychiatrically healthy controls underwent line-scan diffusion tensor imaging. Fractional anisotropy (FA) and mean diffusivity (D(m)) were used to quantify water diffusion, and cross-sectional area was defined with a directional threshold method. Bilaterally reduced FA, but not D(m), was present in the UF of schizophrenia compared with healthy controls. Affective psychosis was intermediate between schizophrenia subjects and healthy controls, but not significantly different from either. For CB, there was no significant group difference for FA or D(m). These findings suggest that UF, but not CB, white matter integrity is altered at the early stage of illness in schizophrenia although it may not be specific to schizophrenia. The CB abnormalities reported in chronic schizophrenia may develop during the later course of the disease.
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Uncinate Fasciculus findings in schizophrenia a magnetic resonance diffusion tensor imaging study
American Journal of Psychiatry, 2002Co-Authors: Marek Kubicki, Carlfredrik Westin, Stephan E Maier, Melissa Frumin, Paul G Nestor, Dean F Salisbury, Ron Kikinis, Ferenc A Jolesz, Robert W Mccarley, Martha E. ShentonAbstract:Objective: Disruptions in connectivity between the frontal and temporal lobes may explain some of the symptoms observed in schizophrenia. Conventional magnetic resonance imaging (MRI) studies, however, have not shown compelling evidence for white matter abnormalities, because white matter fiber tracts cannot be visualized by conventional MRI. Diffusion tensor imaging is a relatively new technique that can detect subtle white matter abnormalities in vivo by assessing the degree to which directionally organized fibers have lost their normal integrity. The first three diffusion tensor imaging studies in schizophrenia showed lower anisotropic diffusion, relative to comparison subjects, in whole-brain white matter, prefrontal and temporal white matter, and the corpus callosum, respectively. Here the authors focus on fiber tracts forming temporal-frontal connections. Method: Anisotropic diffusion was assessed in the Uncinate Fasciculus, the most prominent white matter tract connecting temporal and frontal brain regions, in 15 patients with chronic schizophrenia and 18 normal comparison subjects. A 1.5-T GE Echospeed system was used to acquire 4mm-thick coronal line-scan diffusion tensor images. Maps of the fractional anisotropy were generated to quantify the water diffusion within the Uncinate Fasciculus. Results: Findings revealed a group-byside interaction for fractional anisotropy and for Uncinate Fasciculus area, derived from automatic segmentation. The patients with schizophrenia showed a lack of normal left-greater-than-right asymmetry seen in the comparison subjects. Conclusions: These findings demonstrate the importance of investigating white matter tracts in vivo in schizophrenia and support the hypothesis of a disruption in the normal pattern of connectivity between temporal and frontal brain regions in schizophrenia.
Dominic Job - One of the best experts on this subject based on the ideXlab platform.
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white matter abnormalities in bipolar disorder and schizophrenia detected using diffusion tensor magnetic resonance imaging
Bipolar Disorders, 2009Co-Authors: Jessika E Sussmann, Dominic Job, Mark E Bastin, Eve C Johnstone, Susana Munoz Maniega, Katherine G S Lymer, James Mckirdy, William T J Moorhead, Jeremy Hall, Stephen M LawrieAbstract:OBJECTIVES: Strong qualitative and quantitative evidence exists of white matter abnormalities in both schizophrenia and bipolar disorder (BD). Diffusion tensor imaging (DTI) studies suggest altered connectivity in both disorders. We aim to address the diagnostic specificity of white matter abnormalities in these disorders. METHODS: DTI was used to assess white matter integrity in clinically stable patients with familial BD (n = 42) and familial schizophrenia (n = 28), and in controls (n = 38). Differences in fractional anisotropy (FA) were measured using voxel-based morphometry and automated region of interest analysis. RESULTS: Reduced FA was found in the anterior limb of the internal capsule (ALIC), anterior thalamic radiation (ATR), and in the region of the Uncinate Fasciculus in patients with BD and those with schizophrenia compared with controls. A direct comparison between patient groups found no significant differences in these regions. None of the findings were associated with psychotropic medication. CONCLUSIONS: Reduced integrity of the ALIC, Uncinate Fasciculus, and ATR regions is common to both schizophrenia and BD. These results imply an overlap in white matter pathology, possibly relating to risk factors common to both disorders.
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structural disconnectivity in schizophrenia a diffusion tensor magnetic resonance imaging study
British Journal of Psychiatry, 2003Co-Authors: J Burns, Dominic Job, Mark E Bastin, Heather C Whalley, Tom Macgillivray, Eve C Johnstone, Stephen M LawrieAbstract:Background There is growing evidence that schizophrenia is a disorder of cortical connectivity. Specifically, frontotemporal and frontoparietal connections are thought to be functionally impaired. Diffusion tensor magnetic resonance imaging (DT—MRI) is a technique that has the potential to demonstrate structural disconnectivity in schizophrenia. Aims To investigate the structural integrity of frontotemporal and frontoparietal white matter tracts in schizophrenia. Method Thirty patients with DSM—IV schizophrenia and thirty matched control subjects underwent DT—MRI and structural MRI. Fractional anisotropy — an index of the integrity of white matter tracts — was determined in the Uncinate Fasciculus, the anterior cingulum and the arcuate Fasciculus and analysed using voxel-based morphometry. Results There was reduced fractional anisotropy in the left Uncinate Fasciculus and left arcuate Fasciculus in patients with schizophrenia compared with controls. Conclusions The findings of reduced white matter tract integrity in the left Uncinate Fasciculus and left arcuate Fasciculus suggest that there is frontotemporal and frontoparietal structural disconnectivity in schizophrenia.
