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1.
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.
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4.
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5.
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.
Marcel E. Moran Zoe I. Luscher Harrison McAdams John T. Hsu Deanna Greenstein Liv Clasen Katharine Ludovici Jonae Lloyd Judith Rapoport Susumu Mori Nitin Gogtay 《Schizophrenia bulletin》2015,41(1):66-73
Background:
Diffusion tensor imaging is a neuroimaging method that quantifies white matter (WM) integrity and brain connectivity based on the diffusion of water in the brain. White matter has been hypothesized to be of great importance in the development of schizophrenia as part of the dysconnectivity model. Childhood-onset schizophrenia (COS), is a rare, severe form of the illness that resembles poor outcome adult-onset schizophrenia. We hypothesized that COS would be associated with WM abnormalities relative to a sample of controls.Methods:
To evaluate WM integrity in this population 39 patients diagnosed with COS, 39 of their healthy (nonpsychotic) siblings, and 50 unrelated healthy volunteers were scanned using a diffusion tensor imaging (DTI) sequence during a 1.5 T MRI acquisition. Each DTI scan was processed via atlas-based analysis using a WM parcellation map, and diffeomorphic mapping that shapes a template atlas to each individual subject space. Fractional anisotropy (FA), a measure of WM integrity was averaged over each of the 46 regions of the atlas. Eleven WM regions were examined based on previous reports of WM growth abnormalities in COS.Results:
Of those regions, patients with COS, and their healthy siblings had significantly lower mean FA in the left and right cuneus as compared to the healthy volunteers (P < .005). Together, these findings represent the largest DTI study in COS to date, and provide evidence that WM integrity is significantly impaired in COS. Shared deficits in their healthy siblings might result from increased genetic risk.Key words: DTI, COS, siblings, cuneus, FA 相似文献8.
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9.
Mingying Du Jia Liu Ziqi Chen Xiaoqi Huang Jing Li Weihong Kuang Yanchun Yang Wei Zhang Dong Zhou Feng Bi Keith Maurice Kendrick Qiyong Gong 《Journal of psychiatry & neuroscience : JPN》2014,39(6):397-406
Background
Voxel-based morphometry (VBM) studies have demonstrated that grey matter abnormalities are involved in the pathophysiology of late-life depression (LLD), but the findings are inconsistent and have not been quantitatively reviewed. The aim of the present study was to conduct a meta-analysis that integrated the reported VBM studies, to determine consistent grey matter alterations in individuals with LLD.Methods
A systematic search was conducted to identify VBM studies that compared patients with LLD and healthy controls. We performed a meta-analysis using the effect size signed differential mapping method to quantitatively estimate regional grey matter abnormalities in patients with LLD.Results
We included 9 studies with 11 data sets comprising 292 patients with LLD and 278 healthy controls in our meta-analysis. The pooled and subgroup meta-analyses showed robust grey matter reductions in the right lentiform nucleus extending into the parahippocampus, the hippocampus and the amygdala, the bilateral medial frontal gyrus and the right subcallosal gyrus as well as a grey matter increase in the right lingual gyrus. Meta-regression analyses showed that mean age and the percentage of female patients with LLD were not significantly related to grey matter changes.Limitations
The analysis techniques, patient characteristics and clinical variables of the studies included were heterogeneous, and most participants were medicated.Conclusion
The present meta-analysis is, to our knowledge, the first to overcome previous inconsistencies in the VBM studies of LLD and provide robust evidence for grey matter alterations within fronto–striatal–limbic networks, thereby implicating them in the pathophysiology of LLD. The mean age and the percentage of female patients with LLD did not appear to have a measurable impact on grey matter changes, although we cannot rule out the contributory effects of medication. 相似文献10.
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11.
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12.
Zou K Huang X Li T Gong Q Li Z Ou-yang L Deng W Chen Q Li C Ding Y Sun X 《Journal of psychiatry & neuroscience : JPN》2008,33(6):525-530
Objective
The purpose of our study was to investigate alterations of white matter integrity in adults with major depressive disorder (MDD) using magnetic resonance imaging (MRI).Methods
We performed diffusion tensor imaging with a 3T MRI scanner on 45 patients with major depression and 45 healthy controls matched for age, sex and education. Using a voxel-based analysis, we measured the fractional anisotropy (FA), and we investigated the differences between the patient and control groups. We examined the correlations between the microstructure abnormalities of white matter and symptom severity, age of illness onset and cumulative illness duration, respectively.Results
We found a significant decrease in FA in the left hemisphere, including the anterior limb of the internal capsule and the inferior parietal portion of the superior longitudinal fasciculus, in patients with MDD compared with healthy controls. Diffusion tensor imaging measures in the left anterior limb of the internal capsule were negatively related to the severity of depressive symptoms, even after we controlled for age and sex.Conclusion
Our findings provide new evidence of microstructural changes of white matter in non–late-onset adult depression. Our results complement those observed in late-life depression and support the hypothesis that the disruption of cortical– subcortical circuit integrity may be involved in the etiology of major depressive disorder.Medical subject headings: depressive disorder, major; magnetic resonance imaging; brain diseases 相似文献13.
Kassubek J Juengling FD Sperfeld AD 《Journal of neurology, neurosurgery, and psychiatry》2007,78(11):1209-1212
Objective
X linked spinobulbar muscular atrophy (Kennedy disease (KD)), which is clinically characterised mainly by neuromuscular and endocrine symptoms, has to be considered as a multisystem disorder. Based on clinical evidence of central nervous system involvement, potential KD associated cerebral volume alterations were analysed in vivo.Methods
Whole brain based analysis of optimised voxel based morphometry (VBM) was applied to three dimensional MRI data from 18 genetically confirmed KD patients and compared with age matched controls.Results
Subtle decreases in grey matter volume, mainly localised in frontal areas, were found, but extensive white matter atrophy was observed, particularly in frontal areas, but also involving multiple additional subcortical areas, the cerebellar white matter and the dorsal brainstem from the midbrain to the medulla oblongata.Conclusion
The VBM results demonstrated a morphological correlate of central nervous system involvement in KD, in agreement with aspects of the clinical phenotype (behavioural abnormalities, central–peripheral axonopathy) and with pathohistological findings.Kennedy disease (KD), an X linked spinal and bulbar muscular atrophy, is caused by an expansion of a polymorphic tandem CAG repeat in the first exon of the androgen receptor (AR) gene.1 The clinical phenotype is characterised by an adult onset slowly progressive proximal and symmetrical weakness of the limb and bulbar muscles, muscular atrophy and generalised fasciculations, predominantly affecting the facial muscles.2 Additional symptoms mainly due to partial androgen insensitivity, postural tremor or frequent laryngospasms have been described. More subtle involvement of other neurological systems, such as the somatosensory or cognitive system, have been shown to be part of the clinical spectrum.1,3,4To date, there have been no MRI studies investigating CNS structure in patients with KD. We used voxel based morphometry (VBM) to test the hypothesis that patients with KD have abnormal brain structural changes compared with controls. The VBM approach has been increasingly used as a powerful unbiased tool to investigate structural changes in three dimensional MRI of the whole brain in various neurodegenerative diseases. 相似文献14.
A.R. Alruwaili K. Pannek A. Coulthard R. Henderson N.D. Kurniawan P. McCombe 《Journal of neuroradiology. Journal de neuroradiologie》2018,45(1):41-48
Background and purpose
This study aims to compare the cortical and subcortical deep gray matter (GM) and white matter (WM) of ALS subjects and controls and to compare ALS subjects with (ALScog) and without (ALSnon-cog) cognitive impairment.Materials and methods
The study was performed in 30 ALS subjects, and 19 healthy controls. Structural T1- and diffusion-weighted MRI data were analyzed using voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS).Results
All DTI measures and GM volume differed significantly between ALS subjects and controls. Compared to controls, greater DTI changes were present in ALScog than ALSnon-cog subjects. GM results showed reduction in the caudate nucleus volume in ALScog subjects compared to ALSnon-cog. and comparing all ALS with controls, there were changes on the right side and in a small region in the left middle frontal gyrus.Conclusion
This combined DTI and VBM study showed changes in motor and extra-motor regions. The DTI changes were more extensive in ALScog than ALSnon-cog subjects. It is likely that the inclusion of ALS subjects with cognitive impairment in previous studies resulted in extra-motor WM abnormalities being reported in ALS subjects. 相似文献15.
Zhiyun Jia Yuqing Wang Xiaoqi Huang Weihong Kuang Qizhu Wu Su Lui John A. Sweeney Qiyong Gong 《Journal of psychiatry & neuroscience : JPN》2014,39(3):170-177
Background
The neurobiology of suicide is largely unknown. Studies of white matter tracts in patients with a history of suicidal behaviour have shown alteration in the left anterior limb of the internal capsule (ALIC). Our aim was to determine whether particular target fields of fibre projections through the ALIC are affected in depressed patients who recently attempted suicide.Methods
We studied patients with major depressive disorder (MDD) with and without a history of suicide attempts and healthy controls using diffusion tensor imaging (DTI) and deterministic tractography to generate fibre tract maps for each participant. Tract voxels were coded as being unique to the left ALIC. We compared the mean percentage of fibres projecting to relevant brain regions in the 3 groups using analysis of covariance.Results
We included 63 patients with MDD (23 with and 40 without a history of suicide attempts) and 46 controls in our study. Both groups of depressed patients had reduced fibre projections through the ALIC to the left medial frontal cortex, orbitofrontal cortex and thalamus. Those with a history of suicide attempts had greater abnormalities than those without suicide attempts in the left orbitofrontal cortex and thalamus.Limitations
Diffusion tensor imaging deterministic tracking is unable to distinguish between afferent and efferent pathways, limiting our ability to distinguish the directionality of altered fibre tracts.Conclusion
Frontothalamic loops passing through the ALIC are abnormal in patients with depression and significantly more abnormal in depressed patients with a history of suicide attempts than in those without a history of suicide attempts. Abnormal projections to the orbitofrontal cortex and thalamus may disrupt affective and cognitive functions to confer a heightened vulnerability for suicidal behaviour. 相似文献16.
Alana M. Shepherd Yann Quidé Kristin R. Laurens Nicole O’Reilly Jesseca E. Rowland Philip B. Mitchell Vaughan J. Carr Melissa J. Green 《Journal of psychiatry & neuroscience : JPN》2015,40(1):58-68
Background
Shared genetic vulnerability for schizophrenia and bipolar disorder may be associated with common neuroanatomical features. In view of the evidence for working memory dysfunction as a candidate intermediate phenotype for both disorders, we explored neuroanatomical distinctions between subtypes defined according to working memory (n-back task) performance.Methods
We analyzed T1-weighted MRI scans for patients with schizophrenia-spectrum disorder, bipolar-I disorder (BD-I) and healthy controls. The VBM8 toolbox was used to assess differences in grey and white matter volume across traditional diagnostic groups (schizophrenia v. BD-I). Subsequently, groups were defined as “executively spared” (ES) based on the achievement of greater than 50% accuracy in the 2-back task performance (comparable to performance in the control group) or “executively deficit” (ED) based on the achievement of less than 50% accuracy.Results
Our study included 40 patients with schizophrenia-spectrum disorders, 30 patients with BD-I and 34 controls. Both the schizophrenia and BD-I groups showed grey matter volume reductions relative to the control group, but not relative to each other. The ED subtype (n = 32 [10 BD-I, 22 schizophrenia]) showed grey matter volume reductions in the bilateral superior and medial frontal gyri, right inferior opercular gyri and hippocampus relative to controls. The ES subtype (n = 38 [20 BD-I, 18 schizophrenia]) showed grey matter volume reductions in the right precuneus and left superior and medial orbital frontal gyri relative to controls. The ED subtype showed grey matter volume reduction in the right inferior frontal and precentral gyri relative to the ES subtype. There were no significant differences in white matter volume in any group comparisons.Limitations
This analysis was limited by small sample sizes. Further, insufficient numbers were available to assess a control-deficit comparison group. We were unable to assess the effects of mood stabilizer dose on brain structure.Conclusion
Neuroanatomical commonalities are evident among patients with schizophrenia-spectrum disorders and BD-I with working memory deficits. Reduced inferior frontal lobe volume may mediate cognitive deficits shared across the psychosis–mood spectrum. 相似文献17.
Songran Yang Ping Hua Xinyuan Shang Zaixu Cui Suyu Zhong Gaolang Gong Glyn W. Humphreys 《Journal of psychiatry & neuroscience : JPN》2015,40(4):259-268
Background
Despite being one of the direct causes of depression, whether stroke-induced neuroanatomical deterioration actually plays an important role in the onset of poststroke depression (PSD) is controversial. We assessed the structural basis of PSD, particularly with regard to white matter connectivity.Methods
We evaluated lesion index, fractional anisotropy (FA) reduction and brain structural networks and then analyzed whole brain voxel-based lesions and FA maps. To understand brain damage in the context of brain connectivity, we used a graph theoretical approach. We selected nodes whose degree correlated with the Hamilton Rating Scale for Depression score (p < 0.05, false discovery rate–corrected), after controlling for age, sex, years of education, lesion size, Mini Mental State Examination score and National Institutes of Health Stroke Scale score. We used Poisson regression with robust standard errors to assess the contribution of the identified network toward poststroke major depression.Results
We included 116 stroke patients in the study. Fourteen patients (12.1%) had diagnoses of major depression and 26 (22.4%) had mild depression. We found that lesions in the right insular cortex, left putamen and right superior longitudinal fasciculus as well as FA reductions in broader areas were all associated with major depression. Seventeen nodes were selected to build the depression-related subnetwork. Decreased local efficiency of the subnetwork was a significant risk factor for poststroke major depression (relative risk 0.84, 95% confidence interval 0.72–0.98, p = 0.027).Limitations
The inability of DTI tractography to process fibre crossings may have resulted in inaccurate construction of white matter networks and affected statistical findings.Conclusion
The present study provides, to our knowledge, the first graph theoretical analysis of white matter networks linked to poststroke major depression. These findings provide new insights into the neuroanatomical substrates of depression that develops after stroke. 相似文献18.
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19.
Bora E Harrison BJ Fornito A Cocchi L Pujol J Fontenelle LF Velakoulis D Pantelis C Yücel M 《Journal of psychiatry & neuroscience : JPN》2011,36(1):42-46
Background
Previous diffusion tensor imaging (DTI) studies in patients with obsessive–compulsive disorder (OCD) have reported inconsistent findings, and it is not known whether observed findings are related to abnormalities in axonal structure or myelination.Methods
In this DTI study, we investigated fractional anisotropy, as well as axial and radial diffusivity, in 21 patients with OCD and 29 healthy controls.Results
We found decreased fractional anisotropy in the body of the corpus callosum in the OCD group, which was underpinned by increased radial diffusivity.Limitations
The cross-sectional design was the main limitation.Conclusion
Our findings of increased radial diffusivity provide preliminary evidence for abnormal myelination in patients with OCD. 相似文献20.
Fusar-Poli P Crossley N Woolley J Carletti F Perez-Iglesias R Broome M Johns L Tabraham P Bramon E McGuire P 《Journal of psychiatry & neuroscience : JPN》2011,36(4):239-248