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1.
Lochner C Fouché JP du Plessis S Spottiswoode B Seedat S Fineberg N Chamberlain SR Stein DJ 《Journal of psychiatry & neuroscience : JPN》2012,37(3):193-199
Background
There is evidence to suggest that obsessive–compulsive disorder (OCD) is associated with structural abnormalities in cortico–striato–thalamic circuits, yet the extent of white matter abnormalities is not well established. In this study, we used diffusion tensor imaging (DTI) to examine white matter integrity in specific regions of interest (ROIs) in patients with OCD.Methods
Patients with OCD and sex-, age- and IQ-matched healthy controls underwent DTI. The primary objective was to explore whether patients with OCD had white matter abnormalities in the anterior limb of the internal capsule (ALIC), the uncinate fasciculus, the genu of the corpus callosum and the cingulum. The secondary objective was to evaluate the relation between fractional anisotropy and mean diffusivity in these ROIs and other clinical variables (including age at onset of OCD, OCD severity and levels of depressive and anxiety symptomatology) in patients with OCD.Results
There were 15 patients and 17 controls enrolled in our study. Compared with healthy controls, patients with OCD showed increased fractional anisotropy in bilateral regions of the ALIC adjacent to the body of the caudate, as well as decreased fractional anisotropy in the right anterior limb near the head of the caudate. Patients also had decreased mean diffusivity in the body of the right cingulum and the left anterior cingulum compared with controls. Correlational analyses revealed significant associations of fractional anisotropy and mean diffusivity in select circuits with OCD, depression and anxiety severity scores.Limitations
Inclusion of patients with OCD receiving pharmacotherapy may have been a limitation. In addition, the patients were heterogeneous in terms of their obsessive–compulsive symptom profiles; we did not distinguish between different obsessive–compulsive symptom dimensions.Conclusion
The study results provide further evidence for OCD-related white matter abnormalities in the ALIC and cingulum, consistent with a corticostriatal model of OCD. 相似文献2.
Haller S Xekardaki A Delaloye C Canuto A Lövblad KO Gold G Giannakopoulos P 《Journal of psychiatry & neuroscience : JPN》2011,36(6):391-401
Background
Previous magnetic resonance imaging (MRI) studies in young patients with bipolar disorder indicated the presence of grey matter concentration changes as well as microstructural alterations in white matter in various neocortical areas and the corpus callosum. Whether these structural changes are also present in elderly patients with bipolar disorder with long-lasting clinical evolution remains unclear.Methods
We performed a prospective MRI study of consecutive elderly, euthymic patients with bipolar disorder and healthy, elderly controls. We conducted a voxel-based morphometry (VBM) analysis and a tract-based spatial statistics (TBSS) analysis to assess fractional anisotropy and longitudinal, radial and mean diffusivity derived by diffusion tensor imaging (DTI).Results
We included 19 patients with bipolar disorder and 47 controls in our study. Fractional anisotropy was the most sensitive DTI marker and decreased significantly in the ventral part of the corpus callosum in patients with bipolar disorder. Longitudinal, radial and mean diffusivity showed no significant between-group differences. Grey matter concentration was reduced in patients with bipolar disorder in the right anterior insula, head of the caudate nucleus, nucleus accumbens, ventral putamen and frontal orbital cortex. Conversely, there was no grey matter concentration or fractional anisotropy increase in any brain region in patients with bipolar disorder compared with controls.Limitations
The major limitation of our study is the small number of patients with bipolar disorder.Conclusion
Our data document the concomitant presence of grey matter concentration decreases in the anterior limbic areas and the reduced fibre tract coherence in the corpus callosum of elderly patients with long-lasting bipolar disorder. 相似文献3.
Esther Via Andrew Zalesky Isabel Sánchez Laura Forcano Ben J. Harrison Jesús Pujol Fernando Fernández-Aranda José Manuel Menchón Carles Soriano-Mas Narcís Cardoner Alex Fornito 《Journal of psychiatry & neuroscience : JPN》2014,39(6):367-375
Background
The etiology of anorexia nervosa is still unknown. Multiple and distributed brain regions have been implicated in its pathophysiology, implying a dysfunction of connected neural circuits. Despite these findings, the role of white matter in anorexia nervosa has been rarely assessed. In this study, we used diffusion tensor imaging (DTI) to characterize alterations of white matter microstructure in a clinically homogeneous sample of patients with anorexia nervosa.Methods
Women with anorexia nervosa (restricting subtype) and healthy controls underwent brain DTI. We used tract-based spatial statistics to compare fractional anisotropy (FA) and mean diffusivity (MD) maps between the groups. Furthermore, axial (AD) and radial diffusivity (RD) measures were extracted from regions showing group differences in either FA or MD.Results
We enrolled 19 women with anorexia nervosa and 19 healthy controls in our study. Patients with anorexia nervosa showed significant FA decreases in the parietal part of the left superior longitudinal fasciculus (SLF; pFWE < 0.05), with increased MD and RD but no differences in AD. Patients with anorexia nervosa also showed significantly increased MD in the fornix (pFWE < 0.05), accompanied by decreased FA and increased RD and AD.Limitations
Limitations include our modest sample size and cross-sectional design.Conclusion
Our findings support the presence of white matter pathology in patients with anorexia nervosa. Alterations in the SLF and fornix might be relevant to key symptoms of anorexia nervosa, such as body image distortion or impairments in body–energy–balance and reward processes. The differences found in both areas replicate those found in previous DTI studies and support a role for white matter pathology of specific neural circuits in individuals with anorexia nervosa. 相似文献4.
Chiung-Chih Chang Wen-Neng Chang Chun-Chung Lui Jiun-Jie Wang Chih-Feng Chen Yu-Chang Lee Shun-Sheng Chen Yu-Ting Lin Chi-Wei Huang Ching Chen 《Journal of psychiatry & neuroscience : JPN》2010,35(2):115-125
Background
White matter damage is common after carbon monoxide (CO) intoxication, but in vivo follow-up studies about the mechanism of white matter damage are not possible in pathology series. Diffusion tensor imaging (DTI) and voxel-based morphometry (VBM) can quantify diffusion parameters and volumetric changes in white matter that can be correlated with neuropsychological performances in longitudinal studies.Methods
We examined 9 patients with CO intoxication using DTI, VBM and neuropsychologic tests at an average of 3 and 10 months after CO exposure. We used data from 18 age- and sex-matched controls for comparison.Results
We found that cognitive recovery at 10 months after CO intoxication was not significant, although it was after 3 months. The neuropsychologic tests correlated better for the fibre tract of the semicentrum ovale and not the periventricular fibres. Diffusion measures suggest increases in fractional anisotropy, mean diffusivity and axial eigenvalues over time, while increases in radial eigenvalue were evident at 3 months compared with controls. Periventricular white matter atrophy was observed 10 months after CO intoxicationLimitations
Our study included few cases, and the interpretation of the putative changes on neuroimaging findings cannot be confirmed by histology.Conclusion
Our study showed that the evolution of white matter injury in CO encephalopathy occurred over time. Cognitive recovery was not evident in the follow-up period because of white matter injuries. 相似文献5.
Ke Xu Wenyan Jiang Ling Ren Xuan Ouyang Yifeng Jiang Feng Wu Lingtao Kong Fay Womer Zhening Liu Hilary P. Blumberg Yanqing Tang Fei Wang 《Journal of psychiatry & neuroscience : JPN》2013,38(1):43-48
Background
Abnormalities in the anterior interhemispheric connections provided by the corpus callosum (CC) have long been implicated in major depressive disorder (MDD). The purpose of this study was to investigate interhemispheric connectivity in medication-naive patients with MDD by measuring fractional anisotropy in the CC with diffusion tensor imaging (DTI) techniques.Methods
We obtained DTI scans from medication-naive patients with MDD and from matched healthy controls. Fractional anisotropy values were compared using semiautomatic region of interest methods to localize the regional CC differences between these 2 groups.Results
We enrolled 27 patients and 27 controls in our study. Fractional anisotropy values were significantly lower in the anterior genu of the CC in the MDD group than in the control group (p = 0.009, corrected); results were not significantly different in any other CC subregions.Limitations
As patients with MDD were already experiencing acute episodes, future studies of individuals at risk for MDD are warranted to elucidate the interhemispheric connectivity abnormalities associated with the predisposition to MDD.Conclusion
The findings demonstrate abnormalities in the structural integrity of the anterior genu of the CC in medication-naive individuals with MDD, which may contribute to impairment of interhemispheric connectivity in patients with this disorder. 相似文献6.
Groen WB Buitelaar JK van der Gaag RJ Zwiers MP 《Journal of psychiatry & neuroscience : JPN》2011,36(1):32-40
Background
Recent studies have reported abnormal functional connectivity patterns in the brains of people with autism that may be accompanied by decreases in white matter integrity. Since autism is a developmental disorder, we aim to investigate the nature and location of decreases in white and grey matter integrity in an adolescent sample while accounting for age.Methods
We used structural (T1) imaging to study brain volumetrics and diffusion tensor imaging (DTI) to investigate white and grey matter integrity in people with autism. We obtained magnetic resonance images for adolescents aged 12–18 years with high-functioning autism and from matched controls. Fractional anisotropy and mean diffusivity, as well as grey and white matter volumetrics were analyzed.Results
There were 17 participants with autism and 25 matched controls included in this study. Participants with autism had lower fractional anisotropy in the left and right superior and inferior longitudinal fasciculus, but this effect was not significant after adjusting for age and intelligence quotient (IQ). The kurtosis of the white matter fractional anisotropy probability distribution was higher in this participant group, with and without adjustment for age and IQ. Most notably, however, the mean diffusivity levels were markedly increased in the autism group throughout the brain, and the mean diffusivity probability distributions of both grey and white matter were shifted toward a higher value, particularly with age and IQ adjustment. No volumetric differences in grey and white matter were found.Limitations
We corrected for age and IQ using a linear model. The study was also limited by its sample size, investigated age range and cross-sectional design.Conclusion
The findings suggest that autism is characterized by a generalized reduction of white matter integrity that is associated with an increase of interstitial space. The generalized manifestation of the white matter abnormalities provides an important new perspective on autism as a connectivity disorder. 相似文献7.
Lizhou Chen Xiaoqi Huang Du Lei Ning He Xinyu Hu Ying Chen Yuanyuan Li Jinbo Zhou Lanting Guo Graham J. Kemp Qiyong Gong 《Journal of psychiatry & neuroscience : JPN》2015,40(4):280-287
Background
Attention-deficit/hyperactivity disorder (ADHD) is an early-onset neurodevelopmental disorder with multiple behavioural problems and executive dysfunctions for which neuroimaging studies have reported a variety of abnormalities, with inconsistencies partly owing to confounding by medication and concurrent psychiatric disease. We aimed to investigate the microstructural abnormalities of white matter in unmedicated children and adolescents with pure ADHD and to explore the association between these abnormalities and behavioural symptoms and executive functions.Methods
We assessed children and adolescents with ADHD and healthy controls using psychiatric interviews. Behavioural problems were rated using the revised Conners’ Parent Rating Scale, and executive functions were measured using the Stroop Colour-Word Test and the Wisconsin Card Sorting test. We acquired diffusion tensor imaging data using a 3 T MRI system, and we compared diffusion parameters, including fractional anisotropy (FA) and mean, axial and radial diffusivities, between the 2 groups.Results
Thirty-three children and adolescents with ADHD and 35 healthy controls were included in our study. In patients compared with controls, FA was increased in the left posterior cingulum bundle as a result of both increased axial diffusivity and decreased radial diffusivity. In addition, the averaged FA of the cluster in this region correlated with behavioural measures as well as executive function in patients with ADHD.Limitations
This study was limited by its cross-sectional design and small sample size. The cluster size of the significant result was small.Conclusion
Our findings suggest that white matter abnormalities within the limbic network could be part of the neural underpinning of behavioural problems and executive dysfunction in patients with ADHD. 相似文献8.
Myoung Soo Kim Chun Kee Chung Hee-Won Jung Chul-Kee Park Chi Heon Kim June Sic Kim 《Journal of Korean Neurosurgical Society》2014,55(5):267-272
Objective
Differentiation of demyelination in white matter from axonal damage can be determined using diffusion tensor imaging (DTI). In this study using meningioma patients an attempt was made to evaluate the relationship between preoperative weakness and the changes of diffusion parameters in the corticospinal tract (CST) using DTI.Methods
Twenty-six patients with meningioma were enrolled in this study. Eleven of them suffered from objective motor weakness and were classified as Group 1. The remaining 15 patients did not present motor weakness and were classified as Group 2. Fiber tractography and CST diffusion parameters were obtained using DTIStudio. The ratios (lesion side mean value/contralateral side mean value) of CST diffusion parameters were compared with 1.0 as a test value using a one-sample t-test.Results
In Group 1, fractional anisotropy (FA), tensor trace (TT), and radial diffusivity (RD, λ2 and λ3) of the CST were significantly different between two hemispheres, but axial diffusivity (AD, λ1) of the CST was not significantly different between two hemispheres. In Group 2, FA and λ3 of CST did not differ significantly between the hemispheres. In Group 2, TT, λ1, and λ2 of CST in the ipsilateral hemisphere were significantly higher than those of the unaffected hemisphere. However, the differences were small.Conclusion
Motor weakness was related to a low FA and high TT resulting from increased RD of the CST fibers. CST diffusion changes in patients with weakness are similar to those for demyelination. 相似文献9.
Xiangjuan Kong Xuan Ouyang Haojuan Tao Haihong Liu Li Li Jingping Zhao Zhimin Xue Fei Wang Shaoai Jiang Baoci Shan Zhening Liu 《Journal of psychiatry & neuroscience : JPN》2011,36(2):120-125
Background
Abnormalities in the corpus callosum have long been implicated in schizophrenia. Previous diffusion tensor imaging (DTI) studies in patients with different durations of schizophrenia yielded inconsistent results. By comparing patients with different durations of schizophrenia, we investigated if white matter abnormalities of the corpus callosum emerge at an early stage in the illness or result from pathological progression.Methods
We recruited patients with first-episode schizophrenia, patients with chronic schizophrenia and age-, sex-and handedness-matched healthy controls. We used 2 DTI techniques (voxel-based and fibre-tracking DTI) to investigate differences in corpus callosum integrity among the 3 groups.Results
With both DTI techniques, significantly decreased fractional anisotropy values were identified in the genu of corpus callosum in patients with chronic schizophrenia, but not first-episode schizophrenia, compared with healthy controls.Limitations
This study was cross-sectional, and the sample size was relatively small.Conclusion
Abnormalities in the genu of the corpus callosum might be a progressive process in schizophrenia, perhaps related to disease severity and prognosis. 相似文献10.
Francesco Carletti James B. Woolley Sagnik Bhattacharyya Rocio Perez-Iglesias Paolo Fusar Poli Lucia Valmaggia Matthew R. Broome Elvira Bramon Louise Johns Vincent Giampietro Steve C. R. Williams Gareth J. Barker Philip K. McGuire 《Schizophrenia bulletin》2012,38(6):1170-1179
Background
Psychotic disorders are associated with widespread reductions in white matter (WM) integrity. However, the stage at which these abnormalities first appear and whether they are correlates of psychotic illness, as opposed to an increased vulnerability to psychosis, is unclear. We addressed these issues by using diffusion tensor imaging (DTI) to study subjects at ultra high risk (UHR) of psychosis before and after the onset of illness.Methods
Thirty-two individuals at UHR for psychosis, 32 controls, and 15 patients with first-episode schizophrenia were studied using DTI. The UHR subjects and controls were re-scanned after 28 months. During this period, 8 UHR subjects had developed schizophrenia. Between-group differences in fractional anisotropy (FA) and diffusivity were evaluated cross sectionally and longitudinally using a nonparametric voxel-based analysis.Results
At baseline, WM DTI properties were significantly different between the 3 groups (P < .001). Relative to controls, first-episode patients showed widespread reductions in FA and increases in diffusivity. DTI indices in the UHR group were intermediate relative to those in the other 2 groups. Longitudinal analysis revealed a significant group by time interaction in the left frontal WM (P < .001). In this region, there was a progressive reduction in FA in UHR subjects who developed psychosis that was not evident in UHR subjects who did not make a transition.Conclusions
People at UHR for psychosis show alterations in WM qualitatively similar to, but less severe than, those in patients with schizophrenia. The onset of schizophrenia may be associated with a progressive reduction in the integrity of the frontal WM. 相似文献11.
Yi Liao Xiaoqi Huang Qizhu Wu Chuang Yang Weihong Kuang Mingying Du Su Lui Qiang Yue Raymond C.K. Chan Graham J. Kemp Qiyong Gong 《Journal of psychiatry & neuroscience : JPN》2013,38(1):49-56
Background
Many studies using diffusion tensor imaging (DTI) have demonstrated impaired white matter integrity in patients with major depressive disorder (MDD), with significant results found in diverse brain regions. We sought to identify whether there are consistent changes of regional white matter integrity in patients with MDD, as shown by decreased fractional anisotropy in DTI.Method
A systematic search strategy was used to identify relevant whole brain voxel-based DTI studies of patients with MDD in relation to comparison groups. Relevant databases were searched for studies published between January 1994 and February 2011 using combinations of the terms “DTI” or “diffusion tensor;” “whole brain” or “voxel-based;” and “depress*.” Using the studies that met our inclusion criteria, we performed a meta-analysis of the coordinates of decreased fractional anisotropy using the activation likelihood estimation (ALE) method, which detects 3-dimensional conjunctions of coordinates from multiple studies, weighted by sample size. We then used DTIquery software for fibre tracking to locate the fascicles involved in each region.Results
We included 11 studies with a combined sample of 231 patients with MDD and 261 comparison participants, providing 50 coordinates of decreased fractional anisotropy. Our meta-analysis identified 4 consistent locations of decreased fractional anisotropy in patients with MDD: white matter in the right frontal lobe, right fusiform gyrus, left frontal lobe and right occipital lobe. Fibre tracking showed that the main fascicles involved were the right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, right posterior thalamic radiation and interhemispheric fibres running through the genu and body of the corpus callosum.Limitations
The number of studies included was relatively small, and the DTI data acquisition and analysis techniques were heterogeneous. The ALE method cannot handle studies with no significant group differences.Conclusion
Voxel-based analysis of DTI studies of patients with MDD consistently identified decreased fractional anisotropy in the white matter fascicles connecting the prefrontal cortex within cortical (frontal, temporal and occipital lobes) and subcortical areas (amygdala and hippocampus). This is strong evidence for the involvement of these neural circuits in the pathology of MDD. 相似文献12.
Sean N. Hatton Jim Lagopoulos Daniel F. Hermens Ian B. Hickie Elizabeth Scott Maxwell R. Bennett 《Journal of psychiatry & neuroscience : JPN》2014,39(6):417-427
Background
While many diffusion tensor imaging (DTI) investigations have noted disruptions to white matter integrity in individuals with chronic psychotic disorders, fewer studies have been conducted in young people at the early stages of disease onset. Using whole tract reconstruction techniques, the aim of this study was to identify the white matter pathology associated with the common clinical symptoms and executive function impairments observed in young people with psychosis.Methods
We obtained MRI scans from young people with psychosis and healthy controls. Eighteen major white matter tracts were reconstructed to determine group differences in fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) and then were subsequently correlated with symptomatology and neurocognitive performance.Results
Our study included 42 young people with psychosis (mean age 23 yr) and 45 healthy controls (mean age 25 yr). Compared with the control group, the psychosis group had reduced FA and AD in the left inferior longitudinal fasciculus (ILF) and forceps major indicative of axonal disorganization, reduction and/or loss. These changes were associated with worse overall psychiatric symptom severity, increases in positive and negative symptoms, and worse current levels of depression. The psychosis group also showed FA reductions in the left superior longitudinal fasciculus that were associated with impaired neurocognitive performance in attention and semantic fluency.Limitations
Our analysis grouped 4 subcategories of psychosis together, and a larger follow-up study comparing affective and nonaffective psychoses is warranted.Conclusion
Our findings suggest that impaired axonal coherence in the left ILF and forceps major underpin psychiatric symptoms in young people in the early stages of psychosis. 相似文献13.
Rose SE McMahon KL Janke AL O'Dowd B de Zubicaray G Strudwick MW Chalk JB 《Journal of neurology, neurosurgery, and psychiatry》2006,77(10):1122-1128
Background
Magnetic resonance diffusion tensor imaging (DTI) shows promise in the early detection of microstructural pathophysiological changes in the brain.Objectives
To measure microstructural differences in the brains of participants with amnestic mild cognitive impairment (MCI) compared with an age‐matched control group using an optimised DTI technique with fully automated image analysis tools and to investigate the correlation between diffusivity measurements and neuropsychological performance scores across groups.Methods
34 participants (17 participants with MCI, 17 healthy elderly adults) underwent magnetic resonance imaging (MRI)‐based DTI. To control for the effects of anatomical variation, diffusion images of all participants were registered to standard anatomical space. Significant statistical differences in diffusivity measurements between the two groups were determined on a pixel‐by‐pixel basis using gaussian random field theory.Results
Significantly raised mean diffusivity measurements (p<0.001) were observed in the left and right entorhinal cortices (BA28), posterior occipital–parietal cortex (BA18 and BA19), right parietal supramarginal gyrus (BA40) and right frontal precentral gyri (BA4 and BA6) in participants with MCI. With respect to fractional anisotropy, participants with MCI had significantly reduced measurements (p<0.001) in the limbic parahippocampal subgyral white matter, right thalamus and left posterior cingulate. Pearson''s correlation coefficients calculated across all participants showed significant correlations between neuropsychological assessment scores and regional measurements of mean diffusivity and fractional anisotropy.Conclusions
DTI‐based diffusivity measures may offer a sensitive method of detecting subtle microstructural brain changes associated with preclinical Alzheimer''s disease.Substantial effort is currently being focused towards improving the diagnosis of early Alzheimer''s disease. The term mild cognitive impairment (MCI) is often used to describe the transitional stage between normal ageing and dementia. Owing to the heterogeneity of MCI, not all participants with MCI will have predementia Alzheimer''s disease.1 Peterson et al2 suggested the criteria for a subtype of MCI, so‐called amnestic MCI, which is presumed to present a typical prodrome of dementia in Alzheimer''s disease. People with amnestic MCI have a 10–15% annual conversion rate to Alzheimer''s disease compared with 1–2% in the normal elderly population.2 Neuroimaging studies conducted on participants with MCI using magnetic resonance imaging (MRI) morphological analysis have consistently reported atrophic changes primarily in the medial temporal lobe and, to a lesser extent, in the thalamus and cingulate gyrus.3,4,5 Furthermore, the degree of atrophy in temporal lobe structures correlates with performance on memory tasks3 and with density of neurofibrillar tangles at autopsy.6 These findings support the concept that MRI‐based neuroimaging studies together with neuropsychological assessment may enable identification of participants with MCI which may progress to Alzheimer''s disease, and evaluation of the efficacy of novel treatments.Recent studies using diffusion tensor magnetic resonance imaging (DTI) have shown microstructural changes in the hippocampus of participants with MCI that may not be apparent using standard anatomical imaging.7,8,9 DTI measures the random motion of bulk water in cerebral tissue. When the random motion of water is restricted preferentially in one direction when compared with the orthogonal planes, such as occurs in white matter, diffusion is referred to as anisotropic; in contradistinction, bulk water motion in the cerebrospinal fluid is equal in all directions and is thus referred to as isotropic. Fractional anisotropy, a quantitative measurement of the degree of anisotropy, can be used to probe the integrity of white matter fibre tracts.10 The mean diffusivity is a quantitative measurement of the bulk mean motion of water considered in all directions and is used to interrogate pathological changes in cerebral tissue, such as ischaemia in patients with stroke.10 DTI studies in patients with MCI have shown raised mean diffusivity in the hippocampus and other temporal lobe regions, using manually traced regions of interest (ROI).7,8,9 Although the precise neural correlates of altered mean diffusivity measurements are uncertain, increased mean diffusivity most likely results from loss of neurones, axons and dendrites, resulting in an increase in extracellular space and raised water diffusivity in these regions.7 It is unknown whether such microstructural changes, detectable by DTI, are due to amyloid or neurofibrillar tangle formation or some other neuropathological process in Alzheimer''s disease. However, the finding of a negative correlation between hippocampal diffusivity and volume in people with MCI indicates that both measurements are sensitive to early Alzheimer''s disease neuropathology.7 Using manually defined ROI analyses, a recent study has identified marked changes in volume, mean diffusivity and fractional anisotropy indices in the hippocampus in participants with MCI compared with age‐matched controls.9 Specifically, compared with volume measurements, raised left hippocampal mean diffusivity was found to be a strong independent predictor of poor verbal memory performance in both controls and participants with MCI.In this study, we investigated whether mean diffusivity and fractional anisotropy measurements differed between participants with MCI and age‐matched controls, using an optimised DTI protocol11 and a fully automated voxel‐by‐voxel method of data analysis. This approach assesses the entire brain, rather than just one structure, and circumvents any operator‐introduced errors in the manual selection of ROI for analysis. In addition, we investigated the relationship between measurements of water diffusivity and performance on memory and other cognitive tasks across participants. 相似文献14.
I. Fatih Karababa Huseyin Bayaz?t Nihat K?l??aslan Mustafa Celik Hasan Cece Ekrem Karakas Salih Selek 《Psychiatry investigation》2015,12(3):367-371
Objective
In bipolar disorder, dysregulation of mood may result from white matter abnormalities that change fiber tract length and fiber density. There are few studies evaluating the white matter microstructural changes in bipolar I patients (BD) with depressive episodes. The present study aimed to evaluate anterior corona radiata in BD patients with depressive episode using Diffusion Tensor Imaging (DTI).Methods
Twenty-one patients with bipolar depression and 19 healthy controls were investigated and groups were matched for age and gender. Diffusion-weighted echoplanar brain images (DW-EPI) were obtained using a 1.5 T MRI scanner. Regions of interest (ROIs) were manually placed on directional maps based on principal anisotropy. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of white matter were measured in the anterior corona radiata (ACR) bilaterally by diffusion tensor imaging.Results
There was not a significant difference between groups of age and gender (p>0.05). Significantly lower FA was observed in bilateral ACR in bipolar patients with depression compared with healthy individuals. And there is significantly higher ADC values in the left frontal corona radiate in bipolar patients.Conclusion
White matter abnormalities can be detected in patients with BD using DTI. The neuropathology of these abnormalities is unclear, but neuronal and axonal loss, myelin abnormalities and reduced white matter fiber density are likely to be relevant. 相似文献15.
Tino Prell Thomas Peschel Viktor Hartung Joern Kaufmann Ribanna Klauschies Nils Bodammer Katja Kollewe Reinhard Dengler Julian Grosskreutz 《Clinical neurology and neurosurgery》2013
Background
Amyotrophic lateral sclerosis (ALS) is characterized by pronounced clinical heterogeneity in terms of onset and disease progression. Widespread changes in white matter fibres could be observed by diffusion tensor imaging (DTI), which detects alterations in the degree (diffusivity, ADC) and directedness (fractional anisotropy, FA) of proton movement. The aim of the current study was to determine whether different ALS onset types were reflected in different DTI brain patterns.Methods
Seventeen patients with a diagnosis of ALS (6 bulbar, 11 limb onset) and seventeen age-matched controls received 1.5T DTI, where FA and ADC were analyzed using statistical parametric mapping.Results
In ALS patients, an increased diffusivity in the white matter was found below the precentral gyrus and along the corticospinal tract (CST) right into the internal capsule. The FA was decreased in the posterior limb of internal capsule and in the subcortical white matter in the precentral gyrus. In bulbar onset increased diffusivity was found in the CST, whilst in limb onset, frontal subcortical areas displayed an increased diffusivity.Conclusion
DTI changes can be regarded as prominent features in ALS. Herein we were able to demonstrate discriminating brain DTI patterns due to bulbar or limb onset. 相似文献16.
Frodl T Carballedo A Fagan AJ Lisiecka D Ferguson Y Meaney JF 《Journal of psychiatry & neuroscience : JPN》2012,37(1):37-45
Background
Relatives of patients with major depressive disorder (MDD) and people who experienced early-life adversity are at risk for MDD. The aim of our study was to investigate whether unaffected first-degree healthy relatives (UHRs) of patients with MDD show changes in white matter fibre connections compared with healthy controls and whether there are interactions between early-life adversity and these microstructural changes.Methods
Unaffected, healthy first-degree relatives of patients with MDD and healthy controls without any family history for a psychiatric disease underwent high angular resolution diffusion imaging with 61 diffusion directions. Data were analyzed with tract-based spatial statistics, and findings were confirmed with tractography.Results
Twenty-one UHRs and 24 controls participated in our study. The UHRs showed greater fractional anisotropy than controls in the body and splenium of the corpus callosum, inferior fronto-occipital fasciculus (IFO), left superior longitudinal fasciculus (SLF) and right fornix. The UHRs who experienced more early-life adversity had greater fractional anisotropy than those with less early-life adversity in the splenium of the corpus callosum, fornix, IFO and SLF; in controls, early-life adversity was found to be associated with decreased fractional anisotropy in these fibre tracts.Limitations
Studying participants’ strategies for coping with early-life adversity would have been helpful. Crossing fibres in tracts are a general limitation of the method used.Conclusion
Altogether, our findings provide evidence for greater fractional anisotropy in UHRs and for interaction between early-life adversity and family risk on white matter tracts involved in cognitive–emotional processes. Whether stronger neural fibre connections are associated with more resilience against depression needs to be addressed in future studies. 相似文献17.
Objective
Changes in serum neurosteroid levels have been reported in stress-related disorders such as anxiety and depression, but not in patients with obsessive-compulsive disorder (OCD). We thus investigated such changes in patients with OCD.Methods
We compared the serum levels of progesterone, pregnanolone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEA-S), cortisol and testosterone in 30 patients with OCD and 30 healthy controls.Results
When male and female patients were evaluated together, DHEA and cortisol levels were significantly higher in patients with OCD than the control group. When the genders were evaluated separately, DHEA and cortisol levels were higher in female patients than the female controls. The increase in DHEA levels in female patients is likely an effect of the hypothalamic-pituitary-adrenal (HPA) axis. In contrast, cortisol levels in male patients were higher than the control group, while testosterone levels were lower. The increased cortisol and decreased testosterone levels in male patients likely involves the hypothalamic-pituitary-gonadal (HPG) axis.Conclusion
These findings suggest that neurosteroid levels in patients with OCD should be investigated together with the HPA and HPG axes in future studies. 相似文献18.
Jing-Ming Hou Ming Zhao Wei Zhang Ling-Heng Song Wen-Jing Wu Jian Wang Dai-Quan Zhou Bing Xie Mei He Jun-Wei Guo Wei Qu Hai-Tao Li 《Journal of psychiatry & neuroscience : JPN》2014,39(5):304-311
Background
Obsessive–compulsive disorder (OCD) is a common, heritable neuropsychiatric disorder, hypothetically underpinned by dysfunction of brain cortical–striatal–thalamic–cortical (CSTC) circuits; however, the extent of brain functional abnormalities in individuals with OCD is unclear, and the genetic basis of this disorder is poorly understood. We determined the whole brain functional connectivity patterns in patients with OCD and their healthy first-degree relatives.Methods
We used resting-state fMRI to measure functional connectivity strength in patients with OCD, their healthy first-degree relatives and healthy controls. Whole brain functional networks were constructed by measuring the temporal correlations of all brain voxel pairs and further analyzed using a graph theory approach.Results
We enrolled 39 patients with OCD, 20 healthy first-degree relatives and 39 healthy controls in our study. Compared with healthy controls, patients with OCD showed increased functional connectivity primarily within the CSTC circuits and decreased functional connectivity in the occipital cortex, temporal cortex and cerebellum. Moreover, patients with OCD and their first-degree relatives exhibited overlapping increased functional connectivity strength in the bilateral caudate nucleus, left orbitofrontal cortex (OFC) and left middle temporal gyrus.Limitations
Potential confounding factors, such as medication use, heterogeneity in symptom clusters and comorbid disorders, may have impacted our findings.Conclusion
Our preliminary results suggest that patients with OCD have abnormal resting-state functional connectivity that is not limited to CSTC circuits and involves abnormalities in additional large-scale brain systems, especially the limbic system. Moreover, resting-state functional connectivity strength abnormalities in the left OFC, bilateral caudate nucleus and left middle temporal gyrus may be neuroimaging endophenotypes for OCD. 相似文献19.
Pamela DeRosse George C. Nitzburg Toshikazu Ikuta Bart D. Peters Anil K. Malhotra Philip R. Szeszko 《Schizophrenia bulletin》2015,41(1):104-114
Background:
Previous studies of nonclinical samples exhibiting schizotypal traits have provided support for the existence of a continuous distribution of psychotic symptoms in the general population. Few studies, however, have examined the neural correlates of psychometric schizotypy using structural and diffusion tensor imaging (DTI).Methods:
Healthy volunteers between the ages of 18 and 68 were recruited from the community and assessed using the Schizotypal Personality Questionnaire and received structural and DTI exams. Participants with high (N = 67) and low (N = 71) psychometric schizotypy were compared on gray and white matter volume, and cortical thickness in frontal and temporal lobe regions and on fractional anisotropy (FA) within 5 association tracts traversing the frontal and temporal lobes.Results:
Higher levels of schizotypy were associated with lower overall volumes of gray matter in both the frontal and temporal lobes and lower gray matter thickness in the temporal lobe. Regionally specific effects were evident in both white matter and gray matter volume of the rostral middle frontal cortex and gray matter volume in the pars orbitalis. Moreover, relative to individuals who scored low, those who scored high in schizotypy had lower FA in the inferior fronto-occipital fasciculus as well as greater asymmetry (right > left) in the uncinate fasciculus.Conclusions:
These findings are broadly consistent with recent data on the neurobiological correlates of psychometric schizotypy as well as findings in schizotypal personality disorder and schizophrenia and suggest that frontotemporal lobe dysfunction may represent a core component of the psychosis phenotype.Key words: schizotypy, MRI/DTI, healthy subjects 相似文献20.
Neuregulin 1 genetic variation and anterior cingulum integrity in patients with schizophrenia and healthy controls
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Fei Wang Tianzi Jiang Zhiguo Sun Siew-leng Teng Xingguang Luo Zhongjun Zhu Yufeng Zang Handi Zhang Weihua Yue Mei Qu Tianlan Lu Nan Hong Haiyan Huang Hilary P. Blumberg Dai Zhang 《Journal of psychiatry & neuroscience : JPN》2009,34(3):181-186