Regional changes in brain gray and white matter in patients with schizophrenia demonstrated with voxel-based analysis of MRI

Assessment of Characteristics of Imaging Biomarkers for Quantifying Anterior Cingulate Cortex Changes: A Twin Study of Middle- to Advanced-Aged Populations in East Asia

Background and Objectives: Our aim was to assess genetic and environmental effects on surface morphological parameters for quantifying anterior cingulate cortex (ACC) changes in middle- to advanced-age East Asians using twin analysis. Materials and Methods: Normal twins over 39 years old comprising 37 monozygotic pairs and 17 dizygotic pairs underwent 3-dimensional (3D) T1-weighted imaging of the brain at 3T. Freesurfer-derived ACC parameters including thickness, standard deviation of thickness (STDthickness), volume, surface area, and sulcal morphological parameters (folding, mean, and Gaussian curvatures) were calculated from 3D T1-weighted volume images. Twin analysis with a model involving phenotype variance components of additive genetic effects (A), common environmental effects (C), and unique environmental effects (E) was performed to assess the magnitude of each genetic and environmental influence on parameters. Results: Most parameters fit best with an AE model. Both thickness (A: left 0.73/right 0.71) and surface area (A: left 0.63/right 0.71) were highly heritable. STDthickness was low to moderately heritable (A: left 0.48/right 0.29). Volume was moderately heritable (A: left 0.37). Folding was low to moderately heritable (A: left 0.44/right 0.28). Mean curvature (A: left 0.37/right 0.65) and Gaussian curvature (A: right 0.79) were moderately to highly heritable. Right volume and left Gaussian curvature fit best with a CE model, indicating a relatively weak contribution of genetic factors to these parameters. Conclusions: When assessing ACC changes in middle- to advanced-age East Asians, one must keep in mind that thickness and surface area appear to be strongly affected by genetic factors, whereas sulcal morphological parameters tend to involve environmental factors.

Spectral perturbations of cortical dipoles during a dynamic visuo-spatial working memory task in schizophrenia

Altered neural oscillations during prestimulus-task conditions have been reported to be associated with aberrant information processing in schizophrenia. Spectral perturbations induced by visuo-spatial working memory (VSWM) task were investigated in patients and their first-degree relatives in order to study the biomarkers in schizophrenia. EEG was recorded using 128-channel during VSWM task in 28 patients, 27 first-degree relatives and 25 controls. After pre-processing and ICA, current dipole was estimated for each IC. Total of 1609 independent and localizable EEG components across all groups were used to compute ERSP during different events of task. Patients deactivated DMN, RSN, auditory cortex more compared to controls during search period to perform VSWM task. Relatives showed altered activation of right medial and inferior frontal gyri during different events and loads of task in lower frequencies compared to controls. Relatives also showed hyperactivity in right cingulate and parahippocampal gyri compared to controls. This is suggestive of genetic predisposition in schizophrenia and could act as vulnerability markers, further strengthened by no significant differences between patients and relatives. Altered processing of simultaneous ongoing events in patients and relatives can serve as state and trait-specific features of schizophrenia.

Effects of psychosis-associated genetic markers on brain volumetry: a systematic review of replicated findings and an independent validation

BACKGROUND

Given psychotic illnesses' high heritability and associations with brain structure, numerous neuroimaging-genetics findings have been reported in the last two decades. However, few findings have been replicated. In the present independent sample we aimed to replicate any psychosis-implicated SNPs (single nucleotide polymorphisms), which had previously shown at least two main effects on brain volume.

METHODS

A systematic review for SNPs showing a replicated effect on brain volume yielded 25 studies implicating seven SNPs in five genes. Their effect was then tested in 113 subjects with either schizophrenia, bipolar disorder, 'at risk mental state' or healthy state, for whole-brain and region-of-interest (ROI) associations with grey and white matter volume changes, using voxel-based morphometry.

RESULTS

We found FWER-corrected (Family-wise error rate) (i.e. statistically significant) associations of: (1) CACNA1C-rs769087-A with larger bilateral hippocampus and thalamus white matter, across the whole brain; and (2) CACNA1C-rs769087-A with larger superior frontal gyrus, as ROI. Higher replication concordance with existing literature was found, in decreasing order, for: (1) CACNA1C-rs769087-A, with larger dorsolateral-prefrontal/superior frontal gyrus and hippocampi (both with anatomical and directional concordance); (2) ZNF804A-rs11681373-A, with smaller angular gyrus grey matter and rectus gyri white matter (both with anatomical and directional concordance); and (3) BDNF-rs6265-T with superior frontal and middle cingulate gyri volume change (with anatomical and allelic concordance).

CONCLUSIONS

Most literature findings were not herein replicated. Nevertheless, high degree/likelihood of replication was found for two genome-wide association studies- and one candidate-implicated SNPs, supporting their involvement in psychosis and brain structure.

Two subtypes of schizophrenia identified by an individual-level atypical pattern of tensor-based morphometric measurement

Difficulties in parsing the multiaspect heterogeneity of schizophrenia (SCZ) based on current nosology highlight the need to subtype SCZ using objective biomarkers. Here, utilizing a large-scale multisite SCZ dataset, we identified and validated 2 neuroanatomical subtypes with individual-level abnormal patterns of the tensor-based morphometric measurement. Remarkably, compared with subtype 1, which showed moderate deficits of some subcortical nuclei and an enlarged striatum and cerebellum, subtype 2, which showed cerebellar atrophy and more severe subcortical nuclei atrophy, had a higher subscale score of negative symptoms, which is considered to be a core aspect of SCZ and is associated with functional outcome. Moreover, with the neuroimaging-clinic association analysis, we explored the detailed relationship between the heterogeneity of clinical symptoms and the heterogeneous abnormal neuroanatomical patterns with respect to the 2 subtypes. And the neuroimaging-transcription association analysis highlighted several potential heterogeneous biological factors that may underlie the subtypes. Our work provided an effective framework for investigating the heterogeneity of SCZ from multilevel aspects and may provide new insights for precision psychiatry.

Cerebellar gray matter volume changes in patients with schizophrenia: A voxel-based meta-analysis

BACKGROUND

In schizophrenia, the structural changes in the cerebellum are associated with patients' cognition and motor deficits. However, the findings are inconsistent owing to the heterogeneity in sample size, magnetic resonance imaging (MRI) scanners, and other factors among them. In this study, we conducted a meta-analysis to characterize the anatomical changes in cerebellar subfields in patients with schizophrenia.

METHODS

Systematic research was conducted to identify studies that compare the gray matter volume (GMV) differences in the cerebellum between patients with schizophrenia and healthy controls with a voxel-based morphometry (VBM) method. A coordinate-based meta-analysis was adopted based on seed-based d mapping (SDM) software. An exploratory meta-regression analysis was conducted to associate clinical and demographic features with cerebellar changes.

RESULTS

Of note, 25 studies comprising 996 patients with schizophrenia and 1,109 healthy controls were included in the present meta-analysis. In patients with schizophrenia, decreased GMVs were demonstrated in the left Crus II, right lobule VI, and right lobule VIII, while no increased GMV was identified. In the meta-regression analysis, the mean age and illness duration were negatively associated with the GMV in the left Crus II in patients with schizophrenia.

CONCLUSION

The most significant structural changes in the cerebellum are mainly located in the posterior cerebellar hemisphere in patients with schizophrenia. The decreased GMVs of these regions might partly explain the cognitive deficits and motor symptoms in patients with schizophrenia.

Grey-matter abnormalities in clinical high-risk participants for psychosis

The current study examined the presence of abnormalities in cortical grey-matter (GM) in a sample of clinical high-risk (CHR) participants and examined relationships with psychosocial functioning and neurocognition. CHR-participants (n = 114), participants who did not fulfil CHR-criteria (CHR-negative) (n = 39) as well as a group of healthy controls (HC) (n = 49) were recruited. CHR-status was assessed using the Comprehensive Assessment of At-Risk Mental State (CAARMS) and the Schizophrenia Proneness Interview, Adult Version (SPI-A). The Brief Assessment of Cognition in Schizophrenia Battery (BACS) as well as tests for emotion recognition, working memory and attention were administered. In addition, role and social functioning as well as premorbid adjustment were assessed. No significant differences in GM-thickness and intensity were observed in CHR-participants compared to CHR-negative and HC. Circumscribed abnormalities in GM-intensity were found in the visual and frontal cortex of CHR-participants. Moreover, small-to-moderate correlations were observed between GM-intensity and neuropsychological deficits in the CHR-group. The current data suggest that CHR-participants may not show comprehensive abnormalities in GM. We discuss the implications of these findings for the pathophysiological theories of early stage-psychosis as well as methodological issues and the impact of different recruitment strategies.

Characteristic brain hypoperfusion by 99mTc-ECD single photon emission computed tomography (SPECT) in patients with the first-episode schizophrenia

Objective

In this study, we evaluated brain perfusion in patients with first-episode medicated schizophrenia using the new analytical method, statistical parametric mapping (SPM) applied to single photon emission computed tomography (SPECT).

Method

We performed SPECT with 99-Tc-ethyl cysteinate dimer (99mTc-ECD) of the brain and magnetic resonance imaging (MRI) in patients with schizophrenia (n = 30) and control subjects matched for age and gender (n = 37). A voxel-by-voxel group analysis was performed using SPM2 (Z > 3.0, P < 0.001, uncorrected for multiple comparisons).

Result

In comparison with control subjects, the volumes of the bilateral frontal areas were found to be decreased on MRI. Blood flow was found to be reduced in the bilateral temporal areas in the patients with schizophrenia on SPECT.

Conclusion

In this study, patients with first-episode schizophrenia appeared to have significant bilateral temporal hypoperfusion, although temporal volumes were not significantly decreased in comparison with control subjects. Abnormality of temporal lobe blood flow in schizophrenia may show that functional changes occur earlier than structural changes, and may assist in the diagnosis of schizophrenia.

Brain function, structure and genomic data are linked but show different sensitivity to duration of illness and disease stage in schizophrenia

The progress of schizophrenia at various stages is an intriguing question, which has been explored to some degree using single-modality brain imaging data, e.g. gray matter (GM) or functional connectivity (FC). However it remains unclear how those changes from different modalities are correlated with each other and if the sensitivity to duration of illness and disease stages across modalities is different. In this work, we jointly analyzed FC, GM volume and single nucleotide polymorphisms (SNPs) data of 159 individuals including healthy controls (HC), drug-naïve first-episode schizophrenia (FESZ) and chronic schizophrenia patients (CSZ), aiming to evaluate the links among SNP, FC and GM patterns, and their sensitivity to duration of illness and disease stages in schizophrenia. Our results suggested: 1) both GM and FC highlighted impairments in hippocampal, temporal gyrus and cerebellum in schizophrenia, which were significantly correlated with genes like SATB2, GABBR2, PDE4B, CACNA1C etc. 2) GM and FC presented gradually decrease trend (HC > FESZ>CSZ), while SNP indicated a non-gradual variation trend with un-significant group difference observed between FESZ and CSZ; 3) Group difference between HC and FESZ of FC was more remarkable than GM, and FC presented a stronger negative correlation with duration of illness than GM (p = 0.0006). Collectively, these results highlight the benefit of leveraging multimodal data and provide additional clues regarding the impact of mental illness at various disease stages.

Brain morphologic changes in early stages of psychosis: Implications for clinical application and early intervention

To date, a large number of magnetic resonance imaging (MRI) studies have been conducted in schizophrenia, which generally demonstrate gray matter reduction, predominantly in the frontal and temporo-limbic regions, as well as gross brain abnormalities (e.g., a deviated sulcogyral pattern). Although the causes as well as timing and course of these findings remain elusive, these morphologic changes (especially gross brain abnormalities and medial temporal lobe atrophy) are likely present at illness onset, possibly reflecting early neurodevelopmental abnormalities. In addition, longitudinal MRI studies suggest that patients with schizophrenia and related psychoses also have progressive gray matter reduction during the transition period from prodrome to overt psychosis, as well as initial periods after psychosis onset, while such changes may become almost stable in the chronic stage. These active brain changes during the early phases seem to be relevant to the development of clinical symptoms in a region-specific manner (e.g., superior temporal gyrus atrophy and positive psychotic symptoms), but may be at least partly ameliorated by antipsychotic medication. Recently, increasing evidence from MRI findings in individuals at risk for developing psychosis has suggested that those who subsequently develop psychosis have baseline brain changes, which could be at least partly predictive of later transition into psychosis. In this article, we selectively review previous MRI findings during the course of psychosis and also refer to the possible clinical applicability of these neuroimaging research findings, especially in the diagnosis of schizophrenia and early intervention for psychosis.

Evidence that reduced gray matter volume in psychotic disorder is associated with exposure to environmental risk factors

The aim of this study was to examine whether cannabis use, childhood trauma and urban upbringing are associated with total gray matter volume (GMV) in individuals with (risk for) psychotic disorder and whether this is sex-specific. T1-weighted MRI scans were acquired from 89 patients with a psychotic disorder, 95 healthy siblings of patients with psychotic disorder and 87 controls. Multilevel random regression analyses were used to examine main effects and interactions between group, sex and environmental factors in models of GMV. The three-way interaction between group, sex and cannabis (χ² =12.43, p<0.01), as well as developmental urbanicity (χ² = 6.29, p = 0.01) were significant, indicating that cannabis use and developmental urbanicity were associated with lower GMV in the male patient group (cannabis: B= -32.54, p < 0.01; developmental urbanicity: B= -10.23, p=0.03). For childhood trauma, the two-way interaction with group was significant (χ² = 5.74, p = 0.02), indicating that childhood trauma was associated with reduced GMV in the patient group (B=-9.79, p=0.01). The findings suggest that reduction of GMV in psychotic disorder may be the outcome of differential sensitivity to environmental risks, particularly in male patients.

Early Intervention and a Direction of Novel Therapeutics for the Improvement of Functional Outcomes in Schizophrenia: A Selective Review

BACKGROUND

A recent review reported that the median proportion of patients recovering from schizophrenia was 13.5% and that this did not change over time. Various factors including the duration of untreated psychosis, cognitive impairment, negative symptoms, and morphological changes in the brain influence the functional outcome of schizophrenia. The authors herein reviewed morphological changes in the brain of schizophrenia patients, effects of early intervention, and a direction of developing novel therapeutics to achieve significant improvement of the functional outcome.

METHODS

A selective review of the literature including studies from our department was performed.

RESULTS

Longitudinal structural neuroimaging studies on schizophrenia revealed that volume reductions in the peri-Sylvian regions (e.g., superior temporal gyrus and insula), which are related to positive psychotic symptoms, progress around the onset (critical stage) of schizophrenia, but become stable in the chronic stage. On the other hand, morphological changes in the fronto-thalamic regions and lateral ventricle, which are related to negative symptoms, neurocognitive dysfunction, and the functional outcome, progress during both the critical and chronic stages. These changes in the peri-Sylvian and fronto-thalamic regions may provide a pathophysiological basis for Crow's two-syndrome classification. Accumulated evidence from early intervention trials suggests that the transition risk from an at-risk mental state (ARMS) to psychosis is approximately 30%. Differences in the cognitive performance, event-related potentials (e.g., mismatch negativity), and brain morphology have been reported between ARMS subjects who later developed psychosis and those who did not. Whether early intervention for ARMS significantly improves the long-term recovery rate of schizophrenia patients remains unknown. With respect to the development of novel therapeutics, animal models of schizophrenia based on the N-methyl-d-aspartate receptor hypofunction hypothesis successfully mimicked behavioral changes associated with cognitive impairments characteristic of the disease. Furthermore, these animal models elicited histological changes in the brain similar to those observed in schizophrenia patients, i.e., decreased numbers of parvalbumin-positive interneurons and dendritic spines of pyramidal neurons in the frontal cortex. Some antioxidant compounds were found to ameliorate these behavioral and histological abnormalities.

CONCLUSION

Early intervention coupled with novel therapeutics may offer a promising approach for substantial improvement of the functional outcome of schizophrenia patients.

Prefrontal cortical thinning links to negative symptoms in schizophrenia via the ENIGMA consortium

BACKGROUND

Our understanding of the complex relationship between schizophrenia symptomatology and etiological factors can be improved by studying brain-based correlates of schizophrenia. Research showed that impairments in value processing and executive functioning, which have been associated with prefrontal brain areas [particularly the medial orbitofrontal cortex (MOFC)], are linked to negative symptoms. Here we tested the hypothesis that MOFC thickness is associated with negative symptom severity.

METHODS

This study included 1985 individuals with schizophrenia from 17 research groups around the world contributing to the ENIGMA Schizophrenia Working Group. Cortical thickness values were obtained from T1-weighted structural brain scans using FreeSurfer. A meta-analysis across sites was conducted over effect sizes from a model predicting cortical thickness by negative symptom score (harmonized Scale for the Assessment of Negative Symptoms or Positive and Negative Syndrome Scale scores).

RESULTS

Meta-analytical results showed that left, but not right, MOFC thickness was significantly associated with negative symptom severity (β std = -0.075; p = 0.019) after accounting for age, gender, and site. This effect remained significant (p = 0.036) in a model including overall illness severity. Covarying for duration of illness, age of onset, antipsychotic medication or handedness weakened the association of negative symptoms with left MOFC thickness. As part of a secondary analysis including 10 other prefrontal regions further associations in the left lateral orbitofrontal gyrus and pars opercularis emerged.

CONCLUSIONS

Using an unusually large cohort and a meta-analytical approach, our findings point towards a link between prefrontal thinning and negative symptom severity in schizophrenia. This finding provides further insight into the relationship between structural brain abnormalities and negative symptoms in schizophrenia.

White matter and schizophrenia: A meta-analysis of voxel-based morphometry and diffusion tensor imaging studies

Voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) are the most implemented methodologies to detect alterations of both gray and white matter (WM). However, the role of WM in mental disorders is still not well defined. We aimed at clarifying the role of WM disruption in schizophrenia and at identifying the most frequently involved brain networks. A systematic literature search was conducted to identify VBM and DTI studies focusing on WM alterations in patients with schizophrenia compared to control subjects. We selected studies reporting the coordinates of WM reductions and we performed the anatomical likelihood estimation (ALE). Moreover, we labeled the WM bundles with an anatomical atlas and compared VBM and DTI ALE-scores of each significant WM tract. A total of 59 studies were eligible for the meta-analysis. WM alterations were reported in 31 and 34 foci with VBM and DTI methods, respectively. The most occurred WM bundles in both VBM and DTI studies and largely involved in schizophrenia were long projection fibers, callosal and commissural fibers, part of motor descending fibers, and fronto-temporal-limbic pathways. The meta-analysis showed a widespread WM disruption in schizophrenia involving specific cerebral circuits instead of well-defined regions.

Reduced Thickness of the Anterior Cingulate Cortex in Individuals With an At-Risk Mental State Who Later Develop Psychosis

BACKGROUND

Despite the fact that only a part of the individuals with at-risk mental state (ARMS) for psychosis do develop psychosis, biological markers of future transition to psychosis have not been well documented. Structural abnormality of the anterior cingulate gyrus (ACG), which probably exists prior to the onset of psychosis, could be such a risk marker.

METHODS

We conducted a multicenter magnetic resonance imaging (MRI) study of 3 scanning sites in Japan. 1.5-T 3D MRI scans were obtained from 73 ARMS subjects and 74 age- and gender-matched healthy controls. We measured thickness, volume, and surface area of the ACG using labeled cortical distance mapping and compared these measures among healthy controls, ARMS subjects who later converted to overt psychosis (ARMS-C), and those who did not (ARMS-NC).

RESULTS

Seventeen of 73 (23%) ARMS subjects developed overt psychosis within the follow-up period. The thickness of the left ACG was significantly reduced in ARMS-C relative to healthy subjects (P = .026) while both ARMS-C (P = .001) and ARMS-NC (P = .01) had larger surface areas of the left ACG compared with healthy controls.

CONCLUSION

Further studies will be needed to identify potential markers of future transition to psychosis though cortical thinning of the ACG might be one of the candidates.

Pregenual Anterior Cingulate Gyrus Involvement in Spontaneous Social Interactions in Primates-Evidence from Behavioral, Pharmacological, Neuropsychiatric, and Neurophysiological Findings

The anterior cingulate cortex (ACC) has been implicated in different aspects of cognition and decision making, including social cognition. Several studies suggest that this region is actually formed by sub-regions concerned with distinct cognitive functions. The ACC is usually divided in its rostro-caudal axis, with the caudal ACC playing a major role in processing own actions, and the rostral ACC being related to social cognition. Recently, it has been suggested that the ACC can also be functionally divided in its dorso-ventral axis into ACC gyrus (ACCg) and ACC sulcus (ACCs), with the ACCg having a central role in processing social information. In this context, we propose that the pregenual ACCg might be especially important for engaging in social interactions. We discuss previous findings that support this hypothesis and present evidence suggesting that the activity of pregenual ACCg neurons is modulated during spontaneous social interactions.

Common pattern of gray-matter abnormalities in drug-naive and medicated first-episode schizophrenia: a multimodal meta-analysis

Studies of schizophrenia at drug-naive state and on antipsychotic medication have reported a number of regions of gray-matter (GM) abnormalities but the reports have been inconsistent. The aim of this study was to conduct multimodal meta-analysis to compare the cross-sectional voxel-based morphometry studies of brain GM in antipsychotic-naive first-episode schizophrenia (AN-FES) and those with antipsychotic treatment within 1 year (AT-FES) to determine the similarities and differences in these groups. We conducted two separate meta-analyses containing 24 studies with a sample size of 801 patients and 957 healthy controls. A multimodal meta-analysis method was used to compare the findings between AN-FES and AT-FES. Meta-regression analyses were done to determine the influence of different variables including age, duration of illness, and positive and negative symptom scores. Finally, jack-knife analyses were done to test the robustness of the results. AN-FES and AT-FES showed common patterns of GM abnormalities in frontal (gyrus rectus), superior temporal, left hippocampal and insular cortex. GM in the left supramarginal gyrus and left middle temporal gyrus were found to be increased in AN-FES but decreased in AT-FES, whereas left median cingulate/paracingulate gyri and right hippocampus GM was decreased in AN-FES but increased in AT-FES. Findings suggest that both AN-FES and AT-FES share frontal, temporal and insular regions as common anatomical regions to be affected indicating these to be the primary regions of GM abnormalities in both groups.

Deep Independence Network Analysis of Structural Brain Imaging: Application to Schizophrenia

Linear independent component analysis (ICA) is a standard signal processing technique that has been extensively used on neuroimaging data to detect brain networks with coherent brain activity (functional MRI) or covarying structural patterns (structural MRI). However, its formulation assumes that the measured brain signals are generated by a linear mixture of the underlying brain networks and this assumption limits its ability to detect the inherent nonlinear nature of brain interactions. In this paper, we introduce nonlinear independent component estimation (NICE) to structural MRI data to detect abnormal patterns of gray matter concentration in schizophrenia patients. For this biomedical application, we further addressed the issue of model regularization of nonlinear ICA by performing dimensionality reduction prior to NICE, together with an appropriate control of the complexity of the model and the usage of a proper approximation of the probability distribution functions of the estimated components. We show that our results are consistent with previous findings in the literature, but we also demonstrate that the incorporation of nonlinear associations in the data enables the detection of spatial patterns that are not identified by linear ICA. Specifically, we show networks including basal ganglia, cerebellum and thalamus that show significant differences in patients versus controls, some of which show distinct nonlinear patterns.

Diffusion Imaging of White Matter In Schizophrenia: Progress and Future Directions

Diffusion tensor imaging (DTI) is a powerful tool for the in-vivo assessment of white matter microstructure. The application of DTI methodologies to the study of schizophrenia has supported and advanced the hypothesis of schizophrenia as a disorder of disrupted connectivity. In the context of impaired structural connectivity, the extended time frame of white matter development may offer unique opportunities for treatment that can capitalize on the neural flexibility that is still present in the period leading up to and after disease onset. Therefore, it is important to gain a clear understanding of white matter deficits and how they may emerge and change across the illness. However, while there is broad consistency in the findings of white matter deficits in patients with schizophrenia, there is also a great deal of variability in specific findings across studies. In this review, the aim is to move beyond summarizing case-control analyses, to consider the many factors that may impact DTI measures, to explain variability of findings, and to explore future directions for the field. The topics explored include ways to parse DTI patterns associated with different disease subtypes, ways in which novel and established treatments might interact with or enhance white matter, ways of dissociating developmental change from the disease process itself, and understanding the role of emerging analytic methodologies.

Serum S100B Protein is Specifically Related to White Matter Changes in Schizophrenia

Background: Schizophrenia can be conceptualized as a form of dysconnectivity between brain regions.To investigate the neurobiological foundation of dysconnectivity, one approach is to analyze white matter structures, such as the pathology of fiber tracks. S100B is considered a marker protein for glial cells, in particular oligodendrocytes and astroglia, that passes the blood brain barrier and is detectable in peripheral blood. Earlier Studies have consistently reported increased S100B levels in schizophrenia. In this study, we aim to investigate associations between S100B and structural white matter abnormalities.

Methods: We analyzed data of 17 unmedicated schizophrenic patients (first and recurrent episode) and 22 controls. We used voxel based morphometry (VBM) to detect group differences of white matter structures as obtained from T1-weighted MR-images and considered S100B serum levels as a regressor in an age-corrected interaction analysis.

Results: S100B was increased in both patient subgroups. Using VBM, we found clusters indicating significant differences of the association between S100B concentration and white matter. Involved anatomical structures are the posterior cingulate bundle and temporal white matter structures assigned to the superior longitudinal fasciculus.

Conclusions: S100B-associated alterations of white matter are shown to be existent already at time of first manifestation of psychosis and are distinct from findings in recurrent episode patients. This suggests involvement of S100B in an ongoing and dynamic process associated with structural brain changes in schizophrenia. However, it remains elusive whether increased S100B serum concentrations in psychotic patients represent a protective response to a continuous pathogenic process or if elevated S100B levels are actively involved in promoting structural brain damage.

Patterns of Gray Matter Abnormalities in Schizophrenia Based on an International Mega-analysis

Analyses of gray matter concentration (GMC) deficits in patients with schizophrenia (Sz) have identified robust changes throughout the cortex. We assessed the relationships between diagnosis, overall symptom severity, and patterns of gray matter in the largest aggregated structural imaging dataset to date. We performed both source-based morphometry (SBM) and voxel-based morphometry (VBM) analyses on GMC images from 784 Sz and 936 controls (Ct) across 23 scanning sites in Europe and the United States. After correcting for age, gender, site, and diagnosis by site interactions, SBM analyses showed 9 patterns of diagnostic differences. They comprised separate cortical, subcortical, and cerebellar regions. Seven patterns showed greater GMC in Ct than Sz, while 2 (brainstem and cerebellum) showed greater GMC for Sz. The greatest GMC deficit was in a single pattern comprising regions in the superior temporal gyrus, inferior frontal gyrus, and medial frontal cortex, which replicated over analyses of data subsets. VBM analyses identified overall cortical GMC loss and one small cluster of increased GMC in Sz, which overlapped with the SBM brainstem component. We found no significant association between the component loadings and symptom severity in either analysis. This mega-analysis confirms that the commonly found GMC loss in Sz in the anterior temporal lobe, insula, and medial frontal lobe form a single, consistent spatial pattern even in such a diverse dataset. The separation of GMC loss into robust, repeatable spatial patterns across multiple datasets paves the way for the application of these methods to identify subtle genetic and clinical cohort effects.

Brain imaging during the transition from psychosis prodrome to schizophrenia

Neuroimaging studies have identified patterns of brain abnormalities in various stages of schizophrenia, but whether these abnormalities reflect primary factors associated with the causes of illness or secondary phenomena such as medications has been unclear. Recent work conducted within the prodromal risk paradigm suggests that progressive change in brain structure and function occurs around the time when clinically high-risk individuals transition into full-blown psychosis, effects that cannot be explained by exposure to medications or illness chronicity. This article reviews recent work bearing on the question of the timing of onset and course of brain changes, focusing on structural MRI, diffusion tensor imaging, and resting state connectivity MRI, in association with the onset and course of psychosis. We conclude with a consideration of potential mechanisms underlying progressive tissue changes during the prodromal phase of schizophrenia and implications for prevention.

Altered cortical structures and tract integrity of the mirror neuron system in association with symptoms of schizophrenia

The mirror neuron system (MNS) may be implicated in schizophrenia. This study investigated MNS structures, including the pars opercularis (Pop), the supramarginal gyrus (SMg), the third branch of the superior longitudinal fasciculus, and callosal fibers interconnecting bilateral Pop (CC-Pop) and SMg (CC-SMg), and clarified their relationships with positive and negative symptoms of schizophrenia. Participants comprised 32 schizophrenia patients and 32 matched controls who received T1-weighted structural magnetic resonance imaging (MRI, T1WI) and diffusion spectrum imaging (DSI). The cortical measures were computed from the T1WI data. Tract integrity was assessed using a tractography-based analysis of the generalized fractional anisotropy (GFA) derived from the DSI data. Pearson׳s correlations and multiple linear regression analysis were used to investigate the associations between MNS structures and positive and negative symptom scores of schizophrenia. Cortical thickness in bilateral Pop and SMg were significantly thinner and mean GFA of CC-Pop was significantly decreased in patients. Negative symptoms were significantly correlated with left SMg volume, and positive symptoms were significantly correlated with right SMg thickness. Multiple linear regression analysis showed left SMg volume to be the strongest contributor to the negative symptoms. The association between left SMg volume and negative symptoms may reflect the degree of social cognition impairment in schizophrenia.

Structural abnormalities in schizophrenia: further evidence on the key role of the anterior cingulate cortex

OBJECTIVE

The present study examined whole-brain structural abnormalities in schizophrenia, with a special focus on the anterior and posterior cingulate cortex (ACC, PCC) as this is an understudied issue in schizophrenia.

METHOD

Whole-brain voxel-based morphometry analyses of gray matter (GM) and white matter (WM) were performed to detect volumetric differences between 14 patients with schizophrenia and 14 healthy controls matched for age, sex, educational level and parents' educational level. We examined within-group GM and WM correlations and completed the analysis with measurements of sulci in medial cortical areas.

RESULTS

Compared with the healthy controls, the schizophrenic patients showed significant decreases in GM volumes in the ACC and PCC, and in neighboring WM regions such as the corpus callosum and the fimbriae of the fornix. Moreover, the patient group also displayed a negative correlation between volumes of GM and WM in the ACC. Finally, the patients showed significantly reduced volumes in the right cingulate sulci and left inferior frontal sulci.

CONCLUSION

Our results replicate typical brain-structural abnormalities with new findings in the medial prefrontal cortex, suggested to be a key region in this disorder.

The polymorphism of YWHAE, a gene encoding 14-3-3epsilon, and brain morphology in schizophrenia: a voxel-based morphometric study

Background

YWHAE is a possible susceptibility gene for schizophrenia that encodes 14-3-3epsilon, a Disrupted-in-Schizophrenia 1 (DISC1)-interacting molecule, but the effect of variation in its genotype on brain morphology remains largely unknown.

Methods

In this voxel-based morphometric magnetic resonance imaging study, we conducted whole-brain analyses regarding the effects of YWHAE single-nucleotide polymorphisms (SNPs) (rs28365859, rs11655548, and rs9393) and DISC1 SNP (rs821616) on gray matter volume in a Japanese sample of 72 schizophrenia patients and 86 healthy controls. On the basis of a previous animal study, we also examined the effect of rs28365859 genotype specifically on hippocampal volume.

Results

Whole-brain analyses showed no significant genotype effect of these SNPs on gray matter volume in all subjects, but we found significant genotype-by-diagnosis interaction for rs28365859 in the left insula and right putamen. The protective C allele carriers of rs28365859 had a significantly larger left insula than the G homozygotes only for schizophrenia patients, while the controls with G allele homozygosity had a significantly larger right putamen than the C allele carriers. The C allele carriers had a larger right hippocampus than the G allele homozygotes in schizophrenia patients, but not in healthy controls. No significant interaction was found between rs28365859 and DISC1 SNP on gray matter volume.

Conclusions

These different effects of the YWHAE (rs28365859) genotype on brain morphology in schizophrenia and healthy controls suggest that variation in its genotype might be, at least partly, related to the abnormal neurodevelopment, including in the limbic regions, reported in schizophrenia. Our results also suggest its specific role among YWHAE SNPs in the pathophysiology of schizophrenia.

Structural brain changes associated with antipsychotic treatment in schizophrenia as revealed by voxel-based morphometric MRI: an activation likelihood estimation meta-analysis

BACKGROUND

The results of multiple studies on the association between antipsychotic use and structural brain changes in schizophrenia have been assessed only in qualitative literature reviews to date. We aimed to perform a meta-analysis of voxel-based morphometry (VBM) studies on this association to quantitatively synthesize the findings of these studies.

METHODS

A systematic computerized literature search was carried out through MEDLINE/PubMed, EMBASE, ISI Web of Science, SCOPUS and PsycINFO databases aiming to identify all VBM studies addressing this question and meeting predetermined inclusion criteria. All studies reporting coordinates representing foci of structural brain changes associated with antipsychotic use were meta-analyzed by using the activation likelihood estimation technique, currently the most sophisticated and best-validated tool for voxel-wise meta-analysis of neuroimaging studies.

RESULTS

Ten studies (five cross-sectional and five longitudinal) met the inclusion criteria and comprised a total of 548 individuals (298 patients on antipsychotic drugs and 250 controls). Depending on the methodologies of the selected studies, the control groups included healthy subjects, drug-free patients, or the same patients evaluated repeatedly in longitudinal comparisons (i.e., serving as their own controls). A total of 102 foci associated with structural alterations were retrieved. The meta-analysis revealed seven clusters of areas with consistent structural brain changes in patients on antipsychotics compared to controls. The seven clusters included four areas of relative volumetric decrease in the left lateral temporal cortex [Brodmann area (BA) 20], left inferior frontal gyrus (BA 44), superior frontal gyrus extending to the left middle frontal gyrus (BA 6), and right rectal gyrus (BA 11), and three areas of relative volumetric increase in the left dorsal anterior cingulate cortex (BA 24), left ventral anterior cingulate cortex (BA 24) and right putamen.

CONCLUSIONS

Our results identify the specific brain regions where possible associations between antipsychotic drug usage and structural brain changes in schizophrenia patients are more consistently reported. Additional longitudinal VBM studies including larger and more homogeneous samples of schizophrenia patients may be needed to further disentangle such alterations from those possibly linked to the intrinsic pathological progressive process in schizophrenia.

Reduced anterior cingulate gray matter volume and thickness in subjects with deficit schizophrenia

BACKGROUND

Patients with deficit schizophrenia (D-SZ) differ from patients with the non-deficit form of schizophrenia (ND-SZ) in several aspects such as risk factors, neurobiological correlates, treatment response and clinical outcome. It has been debated if brain morphology could differentiate D-SZ from ND-SZ. Anterior cingulate gyrus (ACG) region regulates cognitive and emotional processing and past studies reported structural changes in this region in patients with SZ.

METHODS

1.5-T 3D MRI scans were obtained from 18 D-SZ patients, 30 ND-SZ patients and 82 healthy controls (HCs). We used FreeSurfer-initalized labeled cortical distance mapping (FSLCDM) to measure ACG gray matter volume, cortical thickness, and area of the gray/white interface. Furthermore, cortical thickness was compared among the 3 groups using the pooled labeled cortical distance mapping (LCDM) method.

RESULTS

The ACG cortex of the D-SZ group was thinner than the ND-SZ group. Pooled LCDM demonstrated that the ACG cortex was bilaterally thinner in both the ND-SZ group and the D-SZ group compared with the control group. The right ACG gray matter volume was significantly reduced in D-SZ patients as compared with healthy controls (p=0.005 CONCLUSION: Our data suggest that qualitative, categorical differences in neuroanatomy may distinguish between deficit and non-deficit subtypes of schizophrenia.

The impact of the genome-wide supported variant in the cyclin M2 gene on gray matter morphology in schizophrenia

BACKGROUND

Genome-wide significant associations of schizophrenia with eight SNPs in the CNNM2, MIR137, PCGEM1, TRIM26, CSMD1, MMP16, NT5C2 and CCDC68 genes have been identified in a recent mega-analysis of genome-wide association studies. To date, the role of these SNPs on gray matter (GM) volumes remains unclear.

METHODS

After performing quality control for minor-allele frequency > 5% using a JPT HapMap sample and our sample, a genotyping call rate > 95% and Hardy-Weinberg equilibrium testing (p > 0.01), five of eight SNPs were eligible for analysis. We used a comprehensive voxel-based morphometry (VBM) technique to investigate the effects of these five SNPs on GM volumes between major-allele homozygotes and minor-allele carriers in Japanese patients with schizophrenia (n = 173) and healthy subjects (n = 449).

RESULTS

The rs7914558 risk variant at CNNM2 was associated with voxel-based GM volumes in the bilateral inferior frontal gyri (right T = 4.96, p = 0.0088, left T = 4.66, p = 0.031). These peak voxels, which were affected by the variant, existed in the orbital region of the inferior frontal gyri. Individuals with the risk G/G genotype of rs7914558 had smaller GM volumes in the bilateral inferior frontal gyri than carriers of the non-risk A-allele. Although several effects of the genotype and the genotype-diagnosis interaction of other SNPs on GM volumes were observed in the exploratory VBM analyses, these effects did not remain after the FWE-correction for multiple tests (p > 0.05).

CONCLUSIONS

Our findings suggest that the genetic variant in the CNNM2 gene could be implicated in the pathogenesis of schizophrenia through the GM volumetric vulnerability of the orbital regions in the inferior frontal gyri.

Association of white matter deficits with clinical symptoms in antipsychotic-naive first-episode schizophrenia: an optimized VBM study using 3T

OBJECT

To examine the whole brain white matter morphology in antipsychotic-naive patients with first-episode schizophrenia (FES) and its correlations with symptom severity.

MATERIALS AND METHODS

High-resolution T1-weighted images of 64 drug-naive FES patients and 64 matched healthy controls were acquired using a 3 T MR imaging system. Then, optimized voxel-based morphometry was performed to compare the group differences. Finally, correlation analyses were conducted between the white matter volume (WMV) changes and clinical symptoms.

RESULTS

The FES showed significantly decreased WMV in the bilateral posterior limb of the internal capsule (PLIC) and right subgyral frontal white matter. The volume of the bilateral PLIC was negatively correlated with the Positive and Negative Syndrome Scale positive scores. Positive correlations were observed between all of the changed WMV measures and the Global Assessment of Functioning scores.

CONCLUSION

The current findings provide further evidence to support internal capsule and subgyral frontal white matter deficits at the early stage of schizophrenia that are potentially related to the core pathophysiology of the disease. Furthermore, these anatomical alterations were related to the clinical symptoms but not the untreated illness duration, suggesting that these deficits are related to aberrations in the neurodevelopmental process and may be relatively stable during the early course of schizophrenia.

Discrimination between schizophrenia and major depressive disorder by magnetic resonance imaging of the female brain

BACKGROUND

Although schizophrenia and major depressive disorder (MDD) differ on a variety of neuroanatomical measures, a diagnostic tool to discriminate these disorders has not yet been established. We tried to identify structural changes of the brain that best discriminate between schizophrenia and MDD on the basis of gray matter volume, ventricle volume, and diffusion tensor imaging (DTI).

METHOD

The first exploration sample consisted of 25 female patients with schizophrenia and 25 females with MDD. Regional brain volumes and fractional anisotropy (FA) values were entered into a discriminant analysis. The second validation sample consisted of 18 female schizophrenia and 16 female MDD patients.

RESULTS

The stepwise discriminant analysis resulted in correct classification rates of 0.80 in the schizophrenic group and 0.76 in MDD. In the second validation sample, the obtained model yielded correct classification rates of 0.72 in the schizophrenia group and 0.88 in the MDD group.

CONCLUSION

Our results suggest that schizophrenia and MDD have differential structural changes in the examined brain regions and that the obtained discriminant score may be useful to discriminate the two disorders.

Neural markers of errors as endophenotypes in neuropsychiatric disorders

Learning from errors is fundamental to adaptive human behavior. It requires detecting errors, evaluating what went wrong, and adjusting behavior accordingly. These dynamic adjustments are at the heart of behavioral flexibility and accumulating evidence suggests that deficient error processing contributes to maladaptively rigid and repetitive behavior in a range of neuropsychiatric disorders. Neuroimaging and electrophysiological studies reveal highly reliable neural markers of error processing. In this review, we evaluate the evidence that abnormalities in these neural markers can serve as sensitive endophenotypes of neuropsychiatric disorders. We describe the behavioral and neural hallmarks of error processing, their mediation by common genetic polymorphisms, and impairments in schizophrenia, obsessive-compulsive disorder, and autism spectrum disorders. We conclude that neural markers of errors meet several important criteria as endophenotypes including heritability, established neuroanatomical and neurochemical substrates, association with neuropsychiatric disorders, presence in syndromally-unaffected family members, and evidence of genetic mediation. Understanding the mechanisms of error processing deficits in neuropsychiatric disorders may provide novel neural and behavioral targets for treatment and sensitive surrogate markers of treatment response. Treating error processing deficits may improve functional outcome since error signals provide crucial information for flexible adaptation to changing environments. Given the dearth of effective interventions for cognitive deficits in neuropsychiatric disorders, this represents a potentially promising approach.

Visual surround suppression in schizophrenia

Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast - a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the target's appearance. Individuals with SZ demonstrated weaker SS compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation SS in SZ may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

Effects of menopause on brain structural changes in schizophrenia

AIM

The aim of this study was to investigate the influences of menopause on brain morphological changes in schizophrenia using magnetic resonance imaging (MRI).

METHODS

Forty female schizophrenia patients, 20 premenopausal and 20 postmenopausal, and 50 female controls underwent cerebral MRI. Optimized voxel-based morphometry was performed with Statistical Parametric Mapping version 5.

RESULTS

Compared with controls, regional gray matter reductions in schizophrenia patients were observed in the insula, superior temporal gyrus, anterior cingulate, parahippocampal gyrus, and thalamus. Direct comparison between the patient groups showed that the gray matter of postmenopausal patients was significantly smaller when compared with premenopausal patients in the left middle frontal gyrus, and no region had significantly lower gray matter volume in premenopausal patients relative to postmenopausal patients. Significant negative correlation between gray matter volume and the interval after menopause was found in the right superior frontal gyrus in the postmenopause patient group.

CONCLUSION

Differential morphological alterations between postmenopausal and premenopausal schizophrenia patients were observed, suggesting that the female hormone plays a protective role against schizophrenia.

Anterior limb of the internal capsule in schizotypal personality disorder: fiber-tract counting, volume, and anisotropy

Mounting evidence suggests that white matter abnormalities and altered subcortical-cortical connectivity may be central to the pathology of schizophrenia (SZ). The anterior limb of the internal capsule (ALIC) is an important thalamo-frontal white-matter tract shown to have volume reductions in SZ and to a lesser degree in schizotypal personality disorder (SPD). While fractional anisotropy (FA) and connectivity abnormalities in the ALIC have been reported in SZ, they have not been examined in SPD. In the current study, magnetic resonance (MRI) and diffusion tensor imaging (DTI) were obtained in age- and sex-matched individuals with SPD (n=33) and healthy controls (HCs; n=38). The ALIC was traced bilaterally on five equally spaced dorsal-to-ventral axial slices from each participant's MRI scan and co-registered to DTI for the calculation of FA. Tractography was used to examine tracts between the ALIC and two key Brodmann areas (BAs; BA10, BA45) within the dorsolateral prefrontal cortex (DLPFC). Compared with HCs, the SPD participants exhibited (a) smaller relative volume at the mid-ventral ALIC slice level but not the other levels; (b) normal FA within the ALIC; (c) fewer relative number of tracts between the most-dorsal ALIC levels and BA10 but not BA45 and (d) fewer dorsal ALIC-DLPFC tracts were associated with greater symptom severity in SPD. In contrast to prior SZ studies that report lower FA, individuals with SPD show sparing. Our findings are consistent with a pattern of milder thalamo-frontal dysconnectivity in SPD than schizophrenia.

Gray matter volume in schizophrenia and bipolar disorder with psychotic features

There is growing evidence that schizophrenia (SZ) and bipolar disorder (BD) overlap significantly in risk factors, neurobiological features, clinical presentations, and outcomes. SZ is characterized by well documented gray matter (GM) abnormalities in multiple frontal, temporal and subcortical structures. Recent voxel-based morphometry (VBM) studies and meta-analyses in BD also report GM reductions in overlapping, albeit less widespread, brain regions. Psychosis, a hallmark of SZ, is also experienced by a significant proportion of BD patients and there is evidence that psychotic BD may be characterized by specific clinical and pathophysiological features. However, there are few studies comparing GM between SZ and psychotic BD. In this study we compared GM volumes in a sample of 58 SZ patients, 28 BD patients experiencing psychotic symptoms and 43 healthy controls using whole-brain voxel-based morphometry. SZ patients had GM reductions in multiple frontal and temporal regions compared to healthy controls and in the subgenual cortex compared to psychotic BD patients. GM volume was increased in the right posterior cerebellum in SZ patients compared to controls. However, psychotic BD patients did not show significant GM deficits compared to healthy controls or SZ patients. We conclude that GM abnormality as measured by VBM analysis is less pronounced in psychotic BD compared to SZ. This may be due to disease-specific factors or medications used more commonly in BD.

Reduced white matter fractional anisotropy and clinical symptoms in schizophrenia: a voxel-based diffusion tensor imaging study

Although not consistently replicated, diffusion tensor imaging (DTI) studies in schizophrenia have revealed lower fractional anisotropy (FA) in various white matter regions, a finding consistent with the disruption of white matter integrity. In this study, we used voxel-based DTI to investigate possible whole-brain differences in the white matter FA values between 58 schizophrenia patients and 58 healthy controls. We also explored the association between FA values and clinical symptoms in schizophrenia. Compared with the controls, the schizophrenia patients showed significant FA reductions in bilateral superior longitudinal fasciculus, bilateral inferior fronto-occipital fasciculus, and genu of right internal capsule. Furthermore, in the patient group, the FA value of the anterior part of the corpus callosum was negatively correlated with the avolition score on the Scale for the Assessment of Negative Symptoms. These findings suggest widespread disruption of white matter integrity in schizophrenia, which could partly explain the severity of negative symptomatology.

The effects of gender on grey matter abnormalities in major psychoses: a comparative voxelwise meta-analysis of schizophrenia and bipolar disorder

BACKGROUND

Recent evidence from genetic and familial studies revitalized the debate concerning the validity of the distinction between schizophrenia and bipolar disorder. Comparing brain imaging findings is an important avenue to examine similarities and differences and, therefore, the validity of the distinction between these conditions. However, in contrast to bipolar disorder, most patient samples in studies of schizophrenia are predominantly male. This a limiting factor for comparing schizophrenia and bipolar disorder since male gender is associated with more severe neurodevelopmental abnormalities, negative symptoms and cognitive deficits in schizophrenia.

METHOD

We used a coordinate-based meta-analysis technique to compare grey matter (GM) abnormalities in male-dominated schizophrenia, gender-balanced schizophrenia and bipolar disorder samples based on published voxel-based morphometry (VBM) studies. In total, 72 English-language, peer reviewed articles published prior to January 2011 were included. All reports used VBM for comparing schizophrenia or bipolar disorder with controls and reported whole-brain analyses in standard stereotactic space.

RESULTS

GM reductions were more extensive in male-dominated schizophrenia compared to gender-balanced bipolar disorder and schizophrenia. In gender-balanced samples, GM reductions were less severe. Compared to controls, GM reductions were restricted to dorsal anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex in schizophrenia and ACC and bilateral fronto-insular cortex in bipolar disorder.

CONCLUSIONS

When gender is controlled, GM abnormalities in bipolar disorder and schizophrenia are mostly restricted to regions that have a role in emotional and cognitive aspects of salience respectively. Dorsomedial and dorsolateral prefrontal cortex were the only regions that showed greater GM reductions in schizophrenia compared to bipolar disorder.

Neuroanatomical abnormalities in schizophrenia: a multimodal voxelwise meta-analysis and meta-regression analysis

Despite an increasing number of published voxel based morphometry studies of schizophrenia, there has been no adequate attempt to examine gray (GM) and white matter (WM) abnormalities and the heterogeneity of published findings. In the current article, we used a coordinate based meta-analysis technique to simultaneously examine GM and WM abnormalities in schizophrenia and to assess the effects of gender, chronicity, negative symptoms and other clinical variables. 79 studies meeting our inclusion criteria were included in the meta-analysis. Schizophrenia was associated with GM reductions in the bilateral insula/inferior frontal cortex, superior temporal gyrus, anterior cingulate gyrus/medial frontal cortex, thalamus and left amygdala. In WM analyses of volumetric and diffusion-weighted images, schizophrenia was associated with decreased FA and/or WM in interhemispheric fibers, anterior thalamic radiation, inferior longitudinal fasciculi, inferior frontal occipital fasciculi, cingulum and fornix. Male gender, chronic illness and negative symptoms were associated with more severe GM abnormalities and illness chronicity was associated with more severe WM deficits. The meta-analyses revealed overlapping GM and WM structural findings in schizophrenia, characterized by bilateral anterior cortical, limbic and subcortical GM abnormalities, and WM changes in regions including tracts that connect these structures within and between hemispheres. However, the available findings are biased towards characteristics of schizophrenia samples with poor prognosis.

Mapping cortical morphology in youth with velocardiofacial (22q11.2 deletion) syndrome

OBJECTIVE

Velocardiofacial syndrome (VCFS; 22q11.2 deletion syndrome) represents one of the highest known risk factors for schizophrenia. Insofar as up to 30% of individuals with this genetic disorder develop schizophrenia, VCFS constitutes a unique, etiologically homogeneous model for understanding the pathogenesis of schizophrenia.

METHOD

Using a longitudinal, case-control design, anatomic magnetic resonance images were acquired to investigate cross-sectional and longitudinal alterations in surface cortical morphology in a cohort of adolescents with VCFS and age-matched typical controls. All participants were scanned at two time points.

RESULTS

Compared with controls, youth with VCFS exhibited alterations in inferior frontal, dorsal frontal, occipital, and cerebellar brain regions at both time points. Little change was observed over time in surface morphology of either study group. However, within the VCFS group only, worsening psychosocial functioning over time was associated with time 2 surface contractions in left middle and inferior temporal gyri. Further, prodromal symptoms at time 2 were associated with surface contractions in the left and right orbitofrontal, temporal, and cerebellar regions and surface protrusions of the supramarginal gyrus.

CONCLUSIONS

These findings advance the understanding of cortical disturbances in VCFS that produce vulnerability for psychosis in this high-risk population.

Straight gyrus morphology in first-episode schizophrenia-spectrum patients

Previous studies on the straight gyrus have shown inconsistent results in first-episode schizophrenia. In the present study, straight gyrus morphometry in first-episode schizophrenia-spectrum patients was investigated by using a region-of-interest methodology. 141 schizophrenia-spectrum patients and 81 healthy subjects were studied. Magnetic resonance imaging brain scans (1.5 T) were obtained and images were analyzed by using BRAINS2. The main resulting measurements were straight gyrus gray matter volume and cortical surface area. Patients with schizophrenia-spectrum disorders did not significantly differ from controls in the straight gyrus morphometric variables evaluated (p>0.115). There was neither significant group-by-side (p>0.199) or group-by-gender interaction (p>0.096). Clinical variables were not significantly related with straight gyrus morphology. Our results, based on a large and representative sample, do not confirm the presence of significant straight gyrus morphometric anomalies in schizophrenia-spectrum disorders, after controlling for potential confounding variables.

Brain anatomical abnormalities in high-risk individuals, first-episode, and chronic schizophrenia: an activation likelihood estimation meta-analysis of illness progression

OBJECTIVE

The present study reviewed voxel-based morphometry (VBM) studies on high-risk individuals with schizophrenia, patients experiencing their first-episode schizophrenia (FES), and those with chronic schizophrenia. We predicted that gray matter abnormalities would show progressive changes, with most extensive abnormalities in the chronic group relative to FES and least in the high-risk group.

METHOD

Forty-one VBM studies were reviewed. Eight high-risk studies, 14 FES studies, and 19 chronic studies were analyzed using anatomical likelihood estimation meta-analysis.

RESULTS

Less gray matter in the high-risk group relative to controls was observed in anterior cingulate regions, left amygdala, and right insula. Lower gray matter volumes in FES compared with controls were also found in the anterior cingulate and right insula but not the amygdala. Lower gray matter volumes in the chronic group were most extensive, incorporating similar regions to those found in FES and high-risk groups but extending to superior temporal gyri, thalamus, posterior cingulate, and parahippocampal gryus. Subtraction analysis revealed less frontotemporal, striatal, and cerebellar gray matter in FES than the high-risk group; the high-risk group had less gray matter in left subcallosal gyrus, left amygdala, and left inferior frontal gyrus compared with FES. Subtraction analysis confirmed lower gray matter volumes through ventral-dorsal anterior cingulate, right insula, left amygdala and thalamus in chronic schizophrenia relative to FES.

CONCLUSIONS

Frontotemporal brain structural abnormalities are evident in nonpsychotic individuals at high risk of developing schizophrenia. The present meta-analysis indicates that these gray matter abnormalities become more extensive through first-episode and chronic illness. Thus, schizophrenia appears to be a progressive cortico-striato-thalamic loop disorder.

Are Bipolar Disorder and Schizophrenia Neuroanatomically Distinct? An Anatomical Likelihood Meta-analysis

Objective: There is renewed debate on whether modern diagnostic classification should adopt a dichotomous or dimensional approach to schizophrenia and bipolar disorder. This study synthesizes data from voxel-based studies of schizophrenia and bipolar disorder to estimate the extent to which these conditions have a common neuroanatomical phenotype. Methods: A post-hoc meta-analytic estimation of the extent to which bipolar disorder, schizophrenia, or both conditions contribute to brain gray matter differences compared to controls was achieved using a novel application of the conventional anatomical likelihood estimation (ALE) method. 19 schizophrenia studies (651 patients and 693 controls) were matched as closely as possible to 19 bipolar studies (540 patients and 745 controls). Result: Substantial overlaps in the regions affected by schizophrenia and bipolar disorder included regions in prefrontal cortex, thalamus, left caudate, left medial temporal lobe, and right insula. Bipolar disorder and schizophrenia jointly contributed to clusters in the right hemisphere, but schizophrenia was almost exclusively associated with additional gray matter deficits (left insula and amygdala) in the left hemisphere. Limitation: The current meta-analytic method has a number of constraints. Importantly, only studies identifying differences between controls and patient groups could be included in this analysis. Conclusion: Bipolar disorder shares many of the same brain regions as schizophrenia. However, relative to neurotypical controls, lower gray matter volume in schizophrenia is more extensive and includes the amygdala. This fresh application of ALE accommodates multiple studies in a relatively unbiased comparison. Common biological mechanisms may explain the neuroanatomical overlap between these major disorders, but explaining why brain differences are more extensive in schizophrenia remains challenging.

Genetic associations of brain structural networks in schizophrenia: a preliminary study

BACKGROUND

Schizophrenia is a complex genetic disorder, with multiple putative risk genes and many reports of reduced cortical gray matter. Identifying the genetic loci contributing to these structural alterations in schizophrenia (and likely also to normal structural gray matter patterns) could aid understanding of schizophrenia's pathophysiology. We used structural parameters as potential intermediate illness markers to investigate genomic factors derived from single nucleotide polymorphism (SNP) arrays.

METHOD

We used research quality structural magnetic resonance imaging (sMRI) scans from European American subjects including 33 healthy control subjects and 18 schizophrenia patients. All subjects were genotyped for 367 SNPs. Linked sMRI and genetic (SNP) components were extracted to reveal relationships between brain structure and SNPs, using parallel independent component analysis, a novel multivariate approach that operates effectively in small sample sizes.

RESULTS

We identified an sMRI component that significantly correlated with a genetic component (r = -.536, p < .00005); components also distinguished groups. In the sMRI component, schizophrenia gray matter deficits were in brain regions consistently implicated in previous reports, including frontal and temporal lobes and thalamus (p < .01). These deficits were related to SNPs from 16 genes, several previously associated with schizophrenia risk and/or involved in normal central nervous system development, including AKT, PI3K, SLC6A4, DRD2, CHRM2, and ADORA2A.

CONCLUSIONS

Despite the small sample size, this novel analysis method identified an sMRI component including brain areas previously reported to be abnormal in schizophrenia and an associated genetic component containing several putative schizophrenia risk genes. Thus, we identified multiple genes potentially underlying specific structural brain abnormalities in schizophrenia.

Reduced gray matter volume of Brodmann's Area 45 is associated with severe psychotic symptoms in patients with schizophrenia

Previous literature has suggested an important role of inferior frontal gyrus, which mainly consists of Brodmann's Area (BA) 44 and 45, in the pathophysiology of schizophrenia. While recent neuroimaging techniques have revealed differential functional correlates of BA 44 and 45 in healthy individuals, previous studies have not yet separately evaluated the gray matter volume reduction of BA 44 and 45 and their relationships to psychotic symptoms in patients with schizophrenia. In the present study, magnetic resonance images were obtained from 29 right-handed male patients with schizophrenia and from 29 age- and handedness-matched healthy male controls. The reliable manual tracing methodology was employed to measure the gray matter volume of BA 44 and BA 45. The severities of psychotic symptoms were evaluated using the five-factor model of positive and negative syndrome scale in the patient group. A significant gray matter volume reduction of both the BA 44 and BA 45 was found bilaterally in the patients with schizophrenia compared with the healthy controls. Among these inferior frontal sub-regions, reduced volume of right BA 45 revealed the largest effect size. In addition, the reduced volume of BA 45 in left hemisphere showed a significant association with the increased severity of delusional behavior, while the severity of disorganized and positive symptoms were correlated with the bilateral BA 45 volumes in the patient group. The findings support an important role of inferior frontal gyrus in the pathophysiology of schizophrenia. The present study further demonstrated that BA 45 might especially contribute to the production of psychotic symptoms in the patients with schizophrenia.

Anterior cingulate and paracingulate sulci morphology in patients with schizophrenia

The anterior cingulate cortex is a cerebral region engaged in several emotional and cognitive functions. The aim of this study was to investigate possible anterior cingulate and paracingulate sulcal abnormalities in schizophrenia. Twenty-three patients with DSM-IV diagnoses of schizophrenia were compared with 23 healthy subjects matched for age, gender, and parental socioeconomic status. Magnetic resonance images were used to explore the morphology of these regions, with volume and maximum depth being measured by an automated method of sulcal recognition. Additionally, voxel-based morphometry (VBM) was performed to analyze possible reduction in gray and white matter of the anterior cingulate region. A smaller volume of the left anterior cingulate sulcus (ACS) was observed in patients with schizophrenia when compared with healthy controls. Furthermore, female patients showed a reduction in volume of the left ACS and an increase of the right paracingulate sulcus (PCS) compared to female controls. There was also a significant relationship between the depth of right PCS and neuroleptic exposure. VBM analysis showed a reduction in left anterior cingulate gray matter. These findings provide further evidence of left anterior middle frontal cortex abnormalities in schizophrenia. In addition, the results suggest gender differences in the structural abnormalities of the illness.

White matter volume abnormalities and associations with symptomatology in schizophrenia

The cerebral white matter (WM) is critically involved in many bio-behavioral functions impaired in schizophrenia. However, the specific neural systems underlying symptomatology in schizophrenia are not well known. By comparing the volume of all brain fiber systems between chronic patients with DSM-III-R schizophrenia (n=88) and matched healthy community controls (n=40), we found that a set of a priori WM regions of local and distal associative fiber systems was significantly different in patients with schizophrenia. There were significant positive correlations between volumes (larger) in anterior callosal, cingulate and temporal deep WM regions (related to distal connections) with positive symptoms, such as hallucinations, delusions and bizarre behavior, and significant negative correlation between volumes (smaller) in occipital and paralimbic superficial WM (related to local connections) and posterior callosal fiber systems with higher negative symptoms, such as alogia. Furthermore, the temporal sagittal system showed significant rightward asymmetry between patients and controls. These observations suggest a pattern of volume WM alterations associated with symptomatology in schizophrenia that may be related in part to predisposition to schizophrenia.

Morphometric brain abnormalities in schizophrenia in a population-based sample: relationship to duration of illness

Biased recruitment and sample selection may cause variability in neuroimaging studies. Epidemiologically principled population-based magnetic resonance imaging (MRI) studies of schizophrenia are very rare. We gathered structural MRI data on 154 subjects from the Northern Finland 1966 Birth Cohort, aged 33-35 (100 controls, 54 schizophrenia patients). Regional differences in density of gray matter, white matter, and cerebrospinal fluid (CSF) were identified between groups using nonparametric statistical analysis, and the relationship of the regional differences to duration of illness was explored. Gray matter reductions were found bilaterally in the cerebellum, thalamus, basal ganglia, middle frontal gyrus, inferior frontal gyrus, precentral gyrus, insula, superior temporal gyrus, fusiform gyrus, parahippocampal gyrus, cuneus, and lingual gyrus; in the left posterior cingulate, superior frontal gyrus, transverse temporal gyrus, and precuneus; and in the right postcentral gyrus. Gray matter excesses were observed bilaterally in the basal ganglia, anterior cingulate, and medial orbitofrontal cortices. There were white matter deficits in an extensive network including inter- and intrahemispheric tracts bilaterally in the frontal, temporal, parietal, and occipital lobes, subcortical structures, cerebellum, and brain stem. CSF excesses were found bilaterally in the lateral ventricles, third ventricle, interhemispheric, and left Sylvian fissure. We replicated the previous findings of structural brain abnormalities in schizophrenia on a general population level. Gray and white matter deficits were associated with duration of illness suggesting either that developmental brain deficits relate to an earlier age of onset or that brain abnormalities in schizophrenia are progressive in nature.

Insular cortex morphometry in first-episode schizophrenia-spectrum patients: Diagnostic specificity and clinical correlations

Evidence so far indicates that the consistent association between insular cortex abnormalities and schizophrenia is already present at early phases of the illness. In the present investigation we aimed to study the specificity of insular structural abnormalities in schizophrenia by using region-of-interest morphometry to assess insular cortex morphological characteristics in the same heterogeneous sample of schizophrenia-spectrum patients. The 225 subjects, comprising 82 schizophrenia patients, 36 schizophreniform disorder patients and 24 patients with nonschizophrenic non-affective psychoses, and 83 healthy individuals were investigated. Magnetic resonance imaging brain scans (1.5T) were obtained and images analysed to evaluate insular cortex morphometric variables. The main resulting measurements were for insular gray matter volume and cortical surface area. The contribution of sociodemographic and clinical characteristics was controlled. Patients with schizophrenia-spectrum disorders did not significantly differ from controls in the insular cortex morphometric variables evaluated (all P's>0.11). Clinical variables were not significantly related with insular morphological changes. Noteworthy is the fact that none of the group morphological measurements varied significantly by gender or hemisphere. Neither did we find significant differences when patients with schizophrenia and with other non-affective psychoses were compared. Contrary to our initial hypotheses, we were unable to demonstrate significant morphometric anomalies in a large and heterogeneous sample of patients with a first-episode of schizophrenia-spectrum disorders.

Anatomy of bipolar disorder and schizophrenia: a meta-analysis

BACKGROUND

Recent genetic results have indicated that the two major, classically distinct forms of psychosis - schizophrenia and bipolar disorder - may share causative factors in common. However it is not clear to what extent they may also have similar profiles of brain abnormality. We used meta-analytic techniques to generate and compare maps of brain structural abnormality in the large samples of patients with both disorders that have been studied using magnetic resonance imaging.

METHOD

A systematic search was conducted for voxel-based morphometry studies examining gray matter in patients with schizophrenia or bipolar disorder. The anatomical distribution of the co-ordinates of gray matter differences was meta-analysed using Anatomical Likelihood Estimation.

RESULTS

Forty-two schizophrenia studies including 2058 patients with schizophrenia and 2131 comparison subjects were compared with fourteen bipolar studies including 366 patients with bipolar disorder and 497 comparison subjects. In schizophrenia, there were extensive gray matter deficits in frontal, temporal, cingulate and insular cortex and thalamus, and increased gray matter in the basal ganglia. In bipolar disorder, gray matter reductions were present in the anterior cingulate and bilateral insula. These substantially overlapped with areas of gray matter reduction in schizophrenia, except for a region of anterior cingulate where gray matter reduction was specific to bipolar disorder.

IMPLICATIONS

In bipolar disorder studies there were consistent regional gray matter reductions in paralimbic regions (anterior cingulate and insula) implicated in emotional processing. Gray matter reductions in schizophrenia studies were more extensive and involved limbic and neocortical structures as well as the paralimbic regions affected in bipolar disorder.

Reduced functional connectivity in a right-hemisphere network for volitional ocular motor control in schizophrenia

Patients with schizophrenia consistently show deficient performance on tasks requiring volitional saccades. We previously reported reduced fractional anisotropy in the white matter underlying right dorsal anterior cingulate cortex in schizophrenia, which, along with lower fractional anisotropy in the right frontal eye field and posterior parietal cortex, predicted longer latencies of volitional saccades. This suggests that reduced microstructural integrity of dorsal anterior cingulate cortex white matter disrupts connectivity in the right hemisphere-dominant network for spatial attention and volitional ocular motor control. To test this hypothesis, we examined functional connectivity of the cingulate eye field component of this network, which is located in dorsal anterior cingulate cortex, during a task comprising volitional prosaccades and antisaccades. In patients with schizophrenia, we expected to find reduced functional connectivity, specifically in the right hemisphere, which predicted prolonged saccadic latency. Twenty-seven medicated schizophrenia outpatients and 21 demographically matched healthy controls performed volitional saccades during functional magnetic resonance imaging. Based on task-related activation, seed regions in the right and left cingulate eye field were defined. In both groups, the right and left cingulate eye field showed positive correlations with the ocular motor network and negative correlations with the default network. Patients showed reduced positive functional connectivity of the cingulate eye field, specifically in the right hemisphere. Negative functional connectivity of the right cingulate eye field predicted faster saccades, but these relations differed by group, and were only present in controls. This pattern of relations suggests that the coordination of activity between ocular motor and default networks is important for efficient task performance and is disrupted in schizophrenia. Along with prior observations of reduced white matter microstructural integrity (fractional anisotropy) in schizophrenia, the present finding of reduced functional connectivity suggests that functional and structural abnormalities of the right cingulate eye field disrupt connectivity in the network for spatial attention and volitional ocular motor control. These abnormalities may contribute to deficits in overcoming prepotency in the service of directing eye gaze and attention to the parts of the environment that are the most behaviourally relevant.