Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
1.
Psychiatry Res Neuroimaging ; 315: 111328, 2021 09 30.
Article in English | MEDLINE | ID: mdl-34260985

ABSTRACT

Auditory verbal hallucination (AVH) is one of the most remarkable symptoms of schizophrenia, with great impact on patients' lives and unclear pathogenesis. Neuroimaging studies have indicated that the development of AVHs is associated with white matter alteration, however, there are still inconsistencies in specific findings across previous investigations. The present study aimed to investigate the characteristics of the microstructural integrity of white matter (WM) in first-episode schizophrenia patients who experience auditory hallucinations. Atlas-based Diffusion Tensor Imaging (DTI) analysis was performed to evaluate the white matter integrity in 37 first-episode schizophrenia patients with AVH, 60 schizophrenia patients without AVH, and 50 healthy controls. Compared with the healthy controls group, AVH showed decreased mean fractional anisotropy (FA) in the genu and body of corpus callosum, right posterior corona radiata, left superior corona radiata, left external capsule, right superior fronto-occipital fasciculus, and higher mean diffusivity (MD) in genu of corpus callosum and left fornix and stria terminalis; whereas the nAVH group showed a much more significant reduction of FA and increased MD in broader brain regions. In addition, a significant positive correlation between FA and the severity of AVHs was observed in right posterior corona radiate. These observations collectively demonstrated that a certain degree of preserved fronto-temporal and interhemispheric connectivity in the early stage of schizophrenia might be associated with the brain capability to generate AVHs.


Subject(s)
Schizophrenia , White Matter , Anisotropy , Diffusion Tensor Imaging , Hallucinations/diagnostic imaging , Humans , Schizophrenia/diagnostic imaging , White Matter/diagnostic imaging
2.
Schizophr Res ; 189: 9-18, 2017 11.
Article in English | MEDLINE | ID: mdl-28268041

ABSTRACT

In the last two decades there has been an increase on task and resting-state functional Magnetic Resonance Imaging (fMRI) studies that explore the brain's functional changes in schizophrenia. However, it remains unclear as to whether the brain's functional changes during the resting state are sensitive to the same brain regions during task fMRI. Therefore, we conducted a systematic literature search of task and resting-state fMRI studies that investigated brain pathological changes in first-episode schizophrenia (Fleischhacker et al.). Nineteen studies met the inclusion criteria; seven were resting state fMRI studies with 371 FES patients and 363 healthy controls and twelve were task fMRI studies with 235 FES patients and 291 healthy controls. We found overlapping task and resting-state fMRI abnormalities in the prefrontal regions, including the dorsal lateral prefrontal cortex, the orbital frontal cortex and the temporal lobe, especially in the left superior temporal gyrus (STG). The findings of this systematic review support the frontotemporal hypothesis of schizophrenia, and the disruption in prefrontal and STG might represent the pathophysiology of schizophrenia disorder at a relatively early stage.


Subject(s)
Cerebral Cortex/diagnostic imaging , Executive Function/physiology , Learning/physiology , Magnetic Resonance Imaging , Rest/physiology , Schizophrenia , Humans , Schizophrenia/diagnostic imaging , Schizophrenia/pathology , Schizophrenia/physiopathology
3.
J Magn Reson Imaging ; 45(1): 157-166, 2017 01.
Article in English | MEDLINE | ID: mdl-27227967

ABSTRACT

PURPOSE: To explore the acute effect of betel quid (BQ) use on functional network connectivity by comparing the global functional brain networks and their subsets before and immediately after BQ chewing. MATERIALS AND METHODS: Resting-state functional magnetic resonance imaging (fMRI) was performed in 27 healthy male participants before and just after chewing BQ on a 3.0T scanner with a gradient-echo echo planar imaging sequence. Independent component analysis (ICA) was used to determine components that represent the brain's functional networks and their spatial aspects of functional connectivity. A paired t-test was used for exploring the connectivity differences in each network before and after BQ chewing. RESULTS: Sixteen networks were identified by ICA. Nine of them showed connectivity differences before and after BQ chewing (P < 0.05 false discovery rate corrected): (A) orbitofrontal, (B) left frontoparietal, (C) visual, (D) right frontoparietal, (E) anterior default mode, (F) medial frontal/anterior cingulate (G) frontotemporal, (H) occipital/parietal, (I) occipital/temporal/cerebellum. Moreover, networks A, B, C, D, G, H, and I showed increased connectivity, while networks E and F showed decreased connectivity in participants after BQ chewing compared to before chewing. CONCLUSION: The acute effects of BQ use appear to actively alter functional connectivity of frontal and default networks that are known to play a key role in addictive behavior. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:157-166.


Subject(s)
Areca/chemistry , Frontal Lobe/drug effects , Frontal Lobe/physiopathology , Magnetic Resonance Imaging/methods , Plant Extracts/adverse effects , Tobacco, Smokeless/adverse effects , Adolescent , Adult , Areca/adverse effects , Connectome/methods , Frontal Lobe/diagnostic imaging , Humans , Male , Mastication , Nerve Net/diagnostic imaging , Nerve Net/drug effects , Nerve Net/physiopathology , Neural Pathways/drug effects , Neural Pathways/physiopathology , Piper betle/chemistry , Plant Extracts/chemistry , Rest
4.
Sci Rep ; 6: 21657, 2016 Feb 17.
Article in English | MEDLINE | ID: mdl-26882844

ABSTRACT

Previous studies have observed reduced suppression of the default mode network (DMN) during cognitive tasks in schizophrenia, suggesting inefficient DMN suppression is critical for the cognitive deficits of schizophrenia. Cognitive function in schizophrenia patients, however, varies from relatively intact to severely impaired. This study, which compared the DMN suppression patterns between first-episode schizophrenia patients with (SZ-Imp) and without (SZ-Pre) impaired cognitive function, may provide further insight into the role of DMN dysfunction in cognitive deficits of schizophrenia. Independent component analysis (ICA) was applied to resting-state fMRI data to identify the DMN in each subject, and then general linear modeling based on the task-fMRI data was used to examine the different DMN activation patterns between groups. We observed that the SZ-Imp group, but not the SZ-Pre group, showed reduced suppression in the medial prefrontal cortex and posterior cingulated cortex when compared to the healthy controls (HC) group. Moreover, less DMN suppression was associated with poorer task performance in both HC and patient groups. Our findings provide the first direct evidence that disrupted DMN activity only exists in schizophrenia patients with impaired cognitive function, supporting the specific neuro-pathological role of inefficient DMN suppression in cognitive deficits of first-episode schizophrenia.


Subject(s)
Brain Mapping/methods , Cognition Disorders/diagnostic imaging , Magnetic Resonance Imaging/methods , Neural Pathways/diagnostic imaging , Schizophrenia/complications , Adult , Cerebral Cortex/pathology , Female , Humans , Male , Prefrontal Cortex/pathology , Psychiatric Status Rating Scales , Schizophrenia/pathology , Young Adult
5.
Schizophr Res ; 171(1-3): 158-65, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26805410

ABSTRACT

BACKGROUND: Several resting-state neuroimaging studies in schizophrenia indicate an excessive brain activity while others report an incoherent brain activity at rest. No direct evidence for the simultaneous presence of both excessive and incoherent brain activity has been established to date. Moreover, it is unclear whether unaffected siblings of schizophrenia patients who share half of the affected patient's genotype also exhibit the excessive and incoherent brain activity that may render them vulnerable to the development of schizophrenia. METHODS: 27 pairs of schizophrenia patients and their unaffected siblings, as well as 27 healthy controls, were scanned using gradient-echo echo-planar imaging at rest. By using amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (Reho), we investigated the intensity and synchronization of local spontaneous neuronal activity in three groups. RESULTS: We observed that increased amplitude and reduced synchronization (coherence) of spontaneous neuronal activity were shared by patients and their unaffected siblings. The key brain regions with this abnormal neural pattern in both patients and siblings included the middle temporal, orbito-frontal, inferior occipital and fronto-insular gyrus. CONCLUSIONS: This abnormal neural pattern of excessive and incoherent neuronal activity shared by schizophrenia patients and their healthy siblings may improve our understanding of neuropathology and genetic predisposition in schizophrenia.


Subject(s)
Cerebral Cortex/pathology , Rest , Schizophrenia/diagnostic imaging , Schizophrenia/genetics , Siblings , Adult , Analysis of Variance , Case-Control Studies , Cerebral Cortex/diagnostic imaging , Echo-Planar Imaging , Female , Humans , Image Processing, Computer-Assisted , Male , Psychiatric Status Rating Scales , Young Adult
6.
BMC Psychiatry ; 15: 152, 2015 Jul 07.
Article in English | MEDLINE | ID: mdl-26149490

ABSTRACT

BACKGROUND: Auditory verbal hallucinations (AVHs) represent one of the most intriguing phenomena in schizophrenia, however, brain abnormalities underlying AVHs remain unclear. The present study examined the association between cortical thickness and AVHs in first-episode schizophrenia. METHOD: High-resolution MR images were obtained in 49 first-episode schizophrenia (FES) patients and 50 well-matched healthy controls (HCs). Among the FES patients, 18 suffered persistent AVHs ("auditory hallucination" AH group), and 31 never experienced AVHs ("no hallucination" NH group). The severity of AVHs was rated by the Auditory Hallucinations Rating Scale (AHRS). Cortical thickness differences among the three groups and their association with AVHs severity were examined. RESULTS: Compared to both HCs and NH patients, AH patients showed lower cortical thickness in the right Heschl's gyrus. The degree of reduction in the cortical thickness was correlated with AVH severity in the AH patients. CONCLUSIONS: Abnormalities of cortical thickness in the Heschl's gyrus may be a physiological factor underlying auditory verbal hallucinations in schizophrenia.


Subject(s)
Auditory Cortex/pathology , Hallucinations/pathology , Schizophrenia/pathology , Adolescent , Adult , Case-Control Studies , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Young Adult
7.
Asia Pac Psychiatry ; 7(1): 78-84, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24259452

ABSTRACT

INTRODUCTION: Major depressive disorder (MDD) has been regarded as the most common psychiatric disorder among hemodialysis (HD) patients. However, few studies have investigated MDD in HD patients in Mainland China. This study sought to investigate the prevalence and treatment of MDD, as well as the sociodemographic and clinical characteristics in this population. METHODS: Two hundred sixty HD patients were screened with the nine-item Patient Health Questionnaire, and the formal diagnosis of MDD was further assessed using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Severity of depressive symptoms was assessed with Hamilton Rating Scale for Depression. Finally, patients meeting diagnostic criteria were compared with those who did not on demographic and clinical characteristics. RESULTS: Among the 260 subjects, 26.2% screened positively and 10% were confirmed to have a diagnosis of MDD. Among HD patients with MDD, 69.2% had severe or very severe depressive symptoms. There was no evidence of a clinical diagnosis or of treatment for MDD in any of the patients' medical records. Those with shorter duration of HD, lower monthly income, and lower levels of blood urea nitrogen were significantly more likely to have a diagnosis of MDD. DISCUSSION: MDD is frequent in HD patients. Regular screening and professional diagnosis should be undertaken to increase the detection and treatment of MDD in HD patients. The effectiveness of interventions for MDD in HD patients deserves further research.


Subject(s)
Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/epidemiology , Renal Dialysis/psychology , Adult , Aged , China/epidemiology , Depressive Disorder, Major/psychology , Female , Humans , Male , Middle Aged , Prevalence , Psychiatric Status Rating Scales , Severity of Illness Index
8.
Schizophr Res ; 158(1-3): 85-90, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25043264

ABSTRACT

BACKGROUND: Schizophrenia (SZ) and bipolar I disorder (BD) share many overlapping clinical features, confounding the current diagnostic systems. Recent studies suggest the posterior cingulate (PCC) and medial prefrontal (MPFC) cortices that are involved in SZ and BD pathophysiology. However, the roles of PCC and MPFC in providing specific distinctive and shared neural substrates between these two disorders remain largely unknown. Examining the neurophysiologic mechanism of these diseases may help explain the clinical observations and differentiate the two disorders. METHODS: We used the Dynamic Casual Modeling (DCM), which is capable of eliciting hidden neuronal dynamics and reveal cross-regulation of multiple neuronal systems, to characterize the pattern of disrupted effective connectivity in the left PCC-MPFC circuit during working memory tasks in 36 SZ and 20 BD patients as well as 29 healthy controls. RESULTS: Compared to the healthy controls, both SZ and BD patient groups exhibited significant negative effective connectivity from the left MPFC to PCC. The negative effective connectivity was more remarkable in schizophrenic patients. Only patients with BD differed from healthy controls with positive effective connectivity from the left PCC to MPFC. CONCLUSIONS: Whole brain analysis revealed deactivation of the left PCC and MPFC across all patient groups. This study provides new insight that changes in effective connectivity of the left MPFC to left PCC circuit during working memory processing may be a core pathophysiological feature distinguishing SZ from BD.


Subject(s)
Bipolar Disorder/physiopathology , Gyrus Cinguli/physiopathology , Memory Disorders/physiopathology , Memory, Short-Term/physiology , Prefrontal Cortex/physiopathology , Schizophrenia/physiopathology , Adult , Bipolar Disorder/drug therapy , Brain Mapping , Female , Functional Laterality , Humans , Magnetic Resonance Imaging , Male , Models, Neurological , Neural Pathways/physiopathology , Neuropsychological Tests , Photic Stimulation , Schizophrenia/drug therapy , Signal Processing, Computer-Assisted , Visual Perception/physiology , Young Adult
9.
Psychiatry Clin Neurosci ; 68(2): 110-9, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24552631

ABSTRACT

AIM: Aberrant brain functional connectivity patterns have been reported in major depressive disorder (MDD). It is unknown whether they can be used in discriminant analysis for diagnosis of MDD. In the present study we examined the efficiency of discriminant analysis of MDD by individualized computer-assisted diagnosis. METHODS: Based on resting-state functional magnetic resonance imaging data, a new approach was adopted to investigate functional connectivity changes in 39 MDD patients and 37 well-matched healthy controls. By using the proposed feature selection method, we identified significant altered functional connections in patients. They were subsequently applied to our analysis as discriminant features using a support vector machine classification method. Furthermore, the relative contribution of functional connectivity was estimated. RESULTS: After subset selection of high-dimension features, the support vector machine classifier reached up to approximately 84% with leave-one-out training during the discrimination process. Through summarizing the classification contribution of functional connectivities, we obtained four obvious contribution modules: inferior orbitofrontal module, supramarginal gyrus module, inferior parietal lobule-posterior cingulated gyrus module and middle temporal gyrus-inferior temporal gyrus module. CONCLUSION: The experimental results demonstrated that the proposed method is effective in discriminating MDD patients from healthy controls. Functional connectivities might be useful as new biomarkers to assist clinicians in computer auxiliary diagnosis of MDD.


Subject(s)
Brain/physiopathology , Depressive Disorder, Major/diagnosis , Nerve Net/physiopathology , Adolescent , Adult , Brain Mapping , Depressive Disorder, Major/physiopathology , Discriminant Analysis , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neural Pathways/physiopathology , Support Vector Machine , Young Adult
10.
Schizophr Res ; 150(1): 144-50, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23920057

ABSTRACT

BACKGROUND: Previous studies imply that interhemispheric disconnectivity plays a more important role on information processing in schizophrenia. However, the role of the aberrant interhemispheric connection in the pathophysiology of this disorder remains unclear. Recently, resting-state functional Magnetic Resonance Imaging (fMRI) has reported to have potentials of mapping functional interactions between pairs of brain hemispheres. METHODS: Resting-state whole-brain functional connectivity analyses were performed on 41 schizophrenia patients and 33 healthy controls. RESULTS: The first-episode schizophrenia patients showed significant aberrant interhemispheric connection in the globus pallidus, medial frontal gyrus and inferior temporal gyrus. The correlation of Wechsler Adult Intelligence Scale scores with odds ratio of the aberrant interhemispheric connections revealed positive correlation in the pallidum (rho=0.335, p=.003) and medial frontal gyrus (rho=0.260, p=.025). The connection in the pallidum was also positively correlated with duration of illness (rho=-0.407, p=.009). Whereas, the aberrant interhemispheric connection in the inferior temporal gyrus was positively correlated with scores of Scale for the Assessment of Negative Symptoms (rho=0.393, p=.012). CONCLUSION: The present study provides fMRI evidence for the aberrant interhemispheric resting-state functional connectivity within resting-state networks in first-episode schizophrenia patients. These aberrant interhemispheric connections, in particular the pallidum, due to its anatomical and functional connectivities, may be the primary disturbance for cognitive impairment, negative symptoms and chronicity of schizophrenia.


Subject(s)
Brain/pathology , Cognition Disorders/etiology , Corpus Callosum/pathology , Schizophrenia/complications , Schizophrenia/pathology , Adolescent , Adult , Algorithms , Antipsychotic Agents/therapeutic use , Brain/blood supply , Brain Mapping , Community Networks , Corpus Callosum/blood supply , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Oxygen/blood , Psychiatric Status Rating Scales , Schizophrenia/drug therapy , Young Adult
11.
PLoS One ; 8(5): e63477, 2013.
Article in English | MEDLINE | ID: mdl-23704911

ABSTRACT

OBJECTIVE: The schizophrenic patients with high suicide risk are characterized by depression, better cognitive function, and prominent positive symptoms. However, the neurobiological basis of suicide attempts in schizophrenia is not clear. The suicide in schizophrenia is implicated in the defects in emotional process and decision-making, which are associated with prefrontal-cingulate circuit. In order to explore the possible neurobiological basis of suicide in schizophrenia, we investigated the correlation of prefrontal-cingulate circuit with suicide risk in schizophrenia via dynamic casual modelling. METHOD: Participants were 33 first-episode schizophrenic patients comprising of a high suicide risk group (N = 14) and a low suicide risk group (N = 19). A comparison group of healthy controls (N = 15) were matched for age, gender and education. N-back tasking functional magnetic resonance imaging data was collected. RESULTS: Compared with healthy controls group, the two patients groups showed decreased task-related suppression during 2-back task state versus baseline state in the left posterior cingulate and medial prefrontal cortex; the hyper-connectivity from the left posterior cingulate cortex to the left medial prefrontal cortex existed in both schizophrenic patients groups, but hypo-connectivity in the opposite direction only existed in the schizophrenic patients group with high suicide risk. CONCLUSIONS: The hyper-connectivity from the left posterior cingulate cortex to the left medial prefrontal cortex may suggest that the abnormal effective connectivity was associated with risk for schizophrenia. The hypo-connectivity in the opposite direction may represent a possible correlate of increased vulnerability to suicide attempt.


Subject(s)
Gyrus Cinguli/physiopathology , Nerve Net/physiopathology , Prefrontal Cortex/physiopathology , Schizophrenia/physiopathology , Suicide , Bayes Theorem , Brain Mapping , Case-Control Studies , Demography , Female , Humans , Magnetic Resonance Imaging , Male , Risk Factors , Young Adult
12.
Arch Psychiatr Nurs ; 27(1): 32-41, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23352023

ABSTRACT

This study aimed at comparing psychosocial factors in inpatients with first-episode and chronic schizophrenia in China. A sample of 197 first-episode schizophrenia inpatients was compared with 392 chronic schizophrenics using Positive and Negative Syndrome Scale, Social Support Rating Scale and Childhood Traumatic Questionnaire. Our findings showed that chronic schizophrenic patients had significant higher negative symptoms but lower on positive symptoms. They were also less likely to receive social support. Our results provide understanding on the existing differences between first-episode and chronic schizophrenia. Therefore, comprehensive nursing interventions are needed to facilitate social support and medication adherence in order to prevent relapses.


Subject(s)
Child Abuse/psychology , Episode of Care , Inpatients/psychology , Schizophrenic Psychology , Social Support , Adult , Child, Preschool , China , Chronic Disease , Cross-Sectional Studies , Female , Hospitals, Psychiatric , Humans , Male , Medication Adherence , Middle Aged , Psychiatric Status Rating Scales/statistics & numerical data , Schizophrenia/therapy
SELECTION OF CITATIONS
SEARCH DETAIL