A serial longitudinal quantitative MRI study of cerebral changes in first-episode schizophrenia using image segmentation and subvoxel registration

Longitudinal assessment of ventricular volume trajectories in early-stage schizophrenia: evidence of both enlargement and shrinkage

BACKGROUND

Lateral ventricular enlargement represents a canonical morphometric finding in chronic patients with schizophrenia; however, longitudinal studies elucidating complex dynamic trajectories of ventricular volume change during critical early disease stages are sparse.

METHODS

We measured lateral ventricular volumes in 113 first-episode schizophrenia patients (FES) at baseline visit (11.7 months after illness onset, SD = 12.3) and 128 age- and sex-matched healthy controls (HC) using 3T MRI. MRI was then repeated in both FES and HC one year later.

RESULTS

Compared to controls, ventricular enlargement was identified in 18.6% of patients with FES (14.1% annual ventricular volume (VV) increase; 95%CI: 5.4; 33.1). The ventricular expansion correlated with the severity of PANSS-negative symptoms at one-year follow-up (p = 0.0078). Nevertheless, 16.8% of FES showed an opposite pattern of statistically significant ventricular shrinkage during ≈ one-year follow-up (-9.5% annual VV decrease; 95%CI: -23.7; -2.4). There were no differences in sex, illness duration, age of onset, duration of untreated psychosis, body mass index, the incidence of Schneiderian symptoms, or cumulative antipsychotic dose among the patient groups exhibiting ventricular enlargement, shrinkage, or no change in VV.

CONCLUSION

Both enlargement and ventricular shrinkage are equally present in the early stages of schizophrenia. The newly discovered early reduction of VV in a subgroup of patients emphasizes the need for further research to understand its mechanisms.

Associations between reproductive history, hormone use, APOE ε4 genotype and cognition in middle- to older-aged women from the UK Biobank

Introduction

Relative to men, women are at a higher risk of developing age-related neurocognitive disorders including Alzheimer's disease. While women's health has historically been understudied, emerging evidence suggests that reproductive life events such as pregnancy and hormone use may influence women's cognition later in life.

Methods

We investigated the associations between reproductive history, exogenous hormone use, apolipoprotein (APOE) ε4 genotype and cognition in 221,124 middle- to older-aged (mean age 56.2 ± 8.0 years) women from the UK Biobank. Performance on six cognitive tasks was assessed, covering four cognitive domains: episodic visual memory, numeric working memory, processing speed, and executive function.

Results

A longer reproductive span, older age at menopause, older age at first and last birth, and use of hormonal contraceptives were positively associated with cognitive performance later in life. Number of live births, hysterectomy without oophorectomy and use of hormone therapy showed mixed findings, with task-specific positive and negative associations. Effect sizes were generally small (Cohen's d < 0.1). While APOE ε4 genotype was associated with reduced processing speed and executive functioning, in a dose-dependent manner, it did not influence the observed associations between female-specific factors and cognition.

Discussion

Our findings support previous evidence of associations between a broad range of female-specific factors and cognition. The positive association between a history of hormonal contraceptive use and cognition later in life showed the largest effect sizes (max. d = 0.1). More research targeting the long-term effects of female-specific factors on cognition and age-related neurocognitive disorders including Alzheimer's disease is crucial for a better understanding of women's brain health and to support women's health care.

Progression of neuroanatomical abnormalities after first-episode of psychosis: A 3-year longitudinal sMRI study

The location, extent and progression of longitudinal morphometric changes after first-episode of psychosis (FEP) remains unclear. We investigated ventricular and cortico-subcortical regions over a 3-year period in FEP patients compared with healthy controls. High resolution 1.5T T1-weighted MR images were obtained at baseline from 28 FEP patients at presentation and 28 controls, and again after 3-years. The longitudinal FreeSurfer pipeline (v.5.3.0) was used for regional volumetric and cortical reconstruction image analyses. Repeated-measures ANCOVA and vertex-wise linear regression analyses compared progressive changes between groups in subcortical structures and cortical thickness respectively. Compared with controls, patients displayed progressively reduced volume of the caudate [F (1,51)=5.86, p=0.02, Hedges' g=0.66], putamen [F (1,51)=6.06, p=0.02, g=0.67], thalamus [F (1,51)=6.99, p=0.01, g=0.72] and increased right lateral ventricular volume [F (1, 51)=4.03, p=0.05], and significantly increased rate of cortical thinning [F (1,52)=5.11, p=0.028)] at a mean difference of 0.84% [95% CI (0.10, 1.59)] in the left lateral orbitofrontal region over the 3-year period. In patients, greater reduction in putamen volume over time was associated with lower cumulative antipsychotic medication dose (r=0.49, p=0.01), and increasing lateral ventricular volume over time was associated with worsening negative symptoms (r=0.41, p=0.04) and poorer global functioning (r= -0.41, p=0.04). This study demonstrates localised progressive structural abnormalities in the cortico-striato-thalamo-cortical circuit after the onset of psychosis, with increasing ventricular volume noted as a neuroanatomical marker of poorer clinical and functional outcome.

Schizophrenia as a progressive brain disease

There is convincing evidence that schizophrenia is characterized by abnormalities in brain volume. At the Department of Psychiatry of the University Medical Centre Utrecht, Netherlands, we have been carrying out neuroimaging studies in schizophrenia since 1995. We focused our research on three main questions. First, are brain volume abnormalities static or progressive in nature? Secondly, can brain volume abnormalities in schizophrenia be explained (in part) by genetic influences? Finally, what environmental factors are associated with the brain volume abnormalities in schizophrenia?

Based on our findings we suggest that schizophrenia is a progressive brain disease. We showed different age-related trajectories of brain tissue loss suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. Moreover, brain volume has been shown to be a useful phenotype for studying schizophrenia. Brain volume is highly heritable and twin and family studies show that unaffected relatives show abnormalities that are similar, but usually present to a lesser extent, to those found in the patients. However, also environmental factors play a role. Medication intake is indeed a confounding factor when interpreting brain volume (change) abnormalities, while independent of antipsychotic medication intake brain volume abnormalities appear influenced by the outcome of the illness.

In conclusion, schizophrenia can be considered as a progressive brain disease with brain volume abnormalities that are for a large part influenced by genetic factors. Whether the progressive volume change is also mediated by genes awaits the results of longitudinal twin analyses. One of the main challenges for the coming years, however, will be the search for gene-by-environment interactions on the progressive brain changes in schizophrenia.

Potential mechanisms for phencyclidine/ketamine-induced brain structural alterations and behavioral consequences

Evidence of structural abnormalities in the nervous system of recreational drug [e.g., phencyclidine (PCP) or ketamine] users and/or preclinical animal research models suggests interference with the activity of multiple neurotransmitters, particularly glutamate neurotransmission. The damage to the central nervous system (CNS) may include neuronal loss, synaptic changes, disturbed neural network formation and reduced projections to subcortical fields. Notably, the reduced projections may considerably compromise the establishment of the subcortical areas, such as the nucleus accumbens located in the basal forebrain. With its abundant dopaminergic innervation, the nucleus accumbens is believed to be directly associated with addictive behaviors and mental disorders. This review seeks to delineate the relationship between PCP/ketamine-induced loss of cortical neurons and the reduced level of polysialic acid neural cell adhesion molecule (PSA-NCAM) in the striatum, and the likely changes in striatal synaptogenesis during development. The basic mechanism of how PSA-NCAM cell surface expression may be regulated will also be discussed, as well as the hypothesis that PSA-NCAM activity is critical to the regulation of synaptic protein expression. Overall, the present review will address the general hypothesis that damage/interruption of cortico-striatal communication and subcortical synaptogenesis could underlie the erratic/sensitization or addictive states produced by chronic or prolonged PCP/ketamine usage.

MRI-based Assessment of 3D Intrafractional Motion of Head and Neck Cancer for Radiation Therapy

PURPOSE

To determine the 3-dimensional (3D) intrafractional motion of head and neck squamous cell carcinoma (HNSCC).

METHODS AND MATERIALS

Dynamic contrast-enhanced magnetic resonance images from 56 patients with HNSCC in the treatment position were analyzed. Dynamic contrast-enhanced magnetic resonance imaging consisted of 3D images acquired every 2.9 seconds for 4 minutes 50 seconds. Intrafractional tumor motion was studied in the 3 minutes 43 seconds of images obtained after initial contrast enhancement. To assess tumor motion, rigid registration (translations only) was performed using a region of interest (ROI) mask around the tumor. The results were compared with bulk body motion from registration to all voxels. Motion was split into systematic motion and random motion. Correlations between the tumor site and random motion were tested. The within-subject coefficient of variation was determined from 8 patients with repeated baseline measures. Random motion was also assessed at the end of the first week (38 patients) and second week (25 patients) of radiation therapy to investigate trends of motion.

RESULTS

Tumors showed irregular occasional rapid motion (eg, swallowing or coughing), periodic intermediate motion (respiration), and slower systematic drifts throughout treatment. For 95% of the patients, displacements due to systematic and random motion were <1.4 mm and <2.1 mm, respectively, 95% of the time. The motion without an ROI mask was significantly (P<.0001, Wilcoxon signed rank test) less than the motion with an ROI mask, indicating that tumors can move independently from the bony anatomy. Tumor motion was significantly (P=.005, Mann-Whitney U test) larger in the hypopharynx and larynx than in the oropharynx. The within-subject coefficient of variation for random motion was 0.33. The average random tumor motion did not increase notably during the first 2 weeks of treatment.

CONCLUSIONS

The 3D intrafractional tumor motion of HNSCC is small, with systematic motion <1.4 mm and random motion <2.1 mm 95% of the time.

Long-term antipsychotic and benzodiazepine use and brain volume changes in schizophrenia: The Northern Finland Birth Cohort 1966 study

High doses of antipsychotics have been associated with loss in cortical and total gray matter in schizophrenia. However, previous imaging studies have not taken benzodiazepine use into account, in spite of evidence suggesting adverse effects such as cognitive impairment and increased mortality. In this Northern Finland Birth Cohort 1966 study, 69 controls and 38 individuals with schizophrenia underwent brain MRI at the ages of 34 and 43 years. At baseline, the average illness duration was over 10 years. Brain structures were delineated using an automated volumetry system, volBrain, and medication data on cumulative antipsychotic and benzodiazepine doses were collected using medical records and interviews. We used linear regression with intracranial volume and sex as covariates; illness severity was also taken into account. Though both medication doses associated to volumetric changes in subcortical structures, after adjusting for each other and the average PANSS total score, higher scan-interval antipsychotic dose associated only to volume increase in lateral ventricles and higher benzodiazepine dose associated with volume decrease in the caudate nucleus. To our knowledge, there are no previous studies reporting associations between benzodiazepine dose and brain structural changes. Further studies should focus on how these observations correspond to cognition and functioning.

The Longitudinal Course of Schizophrenia Across the Lifespan: Clinical, Cognitive, and Neurobiological Aspects

Despite several decades of research, our knowledge of the long-term course of schizophrenia (SZ) is hampered by a lack of homogeneity of both research methods and phenotypic definitions of SZ's course. We provide a comprehensive review of the course of SZ by applying stringent methodological and diagnostic study-selection criteria. We report on positive and negative symptoms, cognition, and findings obtained by neuroimaging. In addition, we perform a meta-analysis of longitudinal studies of cognition in humans. We selected 35 human studies focusing on a narrow SZ phenotype, employing a follow-up duration of six months or more and consistent methodology at the different measurement points. For the meta-analysis on global cognitive change, eight and four studies were used to compare SZ to healthy and psychiatric controls, respectively. We find that the course of SZ is characterized by a constancy or even improvement of positive and negative symptoms and by fairly stable cognitive impairment, reflecting structural frontal and temporal cortical pathology. Progressive changes of the frontal cortex appear to develop in parallel with changes in symptomatology and executive impairment. Despite stable differences in cognition between patients and controls over the time intervals studied, high heterogeneity in the magnitude of effect sizes is present, and age is identified as one of its potential sources. Meta-regression shows these magnitudes to depend on the age at study inclusion. For future research, a combination of longitudinal and cross-sectional research designs is warranted to better account for potential cohort effects.

Brain Structural Effects of Antipsychotic Treatment in Schizophrenia: A Systematic Review

The findings about the progressive brain changes in schizophrenia are controversial, and the potential confounding effect of antipsychotics on brain structure is still under debate. The goal of the current article was to review the existing longitudinal neuroimaging studies addressing the impact of antipsychotic drug treatment on brain changes in schizophrenia. A comprehensive search of PubMed was performed using combinations of key terms distributed into four blocks: "MRI", "longitudinal", "schizophrenia" and "antipsychotic". Studies were considered to be eligible for the review if they were original articles. Studies that examined only changes in brain density were excluded. A total of 41 MRI studies were identified and reviewed. Longitudinal MRI studies did not provide a consistent notion of the effects of antipsychotic treatment on the pattern of brain changes over time in schizophrenia. Overall, most of the included articles did not find a linear relationship between the degree of exposure and progressive brain changes. Further short- and longterm studies are warranted to a better understanding of the influence of antipsychotics in brain structural changes in schizophrenia and also to verify whether first and second generation antipsychotics may differentially affect brain morphometry.

Evidence for progressive brain abnormalities in early schizophrenia: a cross-sectional structural and functional connectivity study

It has long been debated whether a progressive process is involved in schizophrenia. The aim of the current study was to determine whether a progressive process was involved in patients with early schizophrenia, who were drug naive or had received short-term minimal antipsychotic treatment to avoid the distortion through medication effects. Twenty-eight patients with schizophrenia with illness-duration of up to 3 years and twenty-six matched healthy controls were recruited. Structural and functional brain networks were examined based on diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI). The intergroup differences and correlation with illness duration in the patient group were surveyed. The schizophrenic patients showed lower fractional anisotropy (FA) values in the corpus callosum and corona radiata. Negative correlations of illness duration with FA values were observed in similar regions. During functional analysis, reduced functional connectivity between bilateral temporoparietal-junction (TPJ) and the posterior cingulate cortex (PCC) were found in the default mode network (DMN) in schizophrenic patients. In addition, the left TPJ showed gradually weaker functional connectivity with PCC and the medial prefrontal cortex (MPFC) in DMN as the duration of schizophrenia increased. The results suggested that early in the disease process patients have decreased connectivity in both structural and functional networks and that the weaker structural and functional connectivity negatively correlated with illness duration, which provided evidence for progressive brain abnormalities in early 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.

Age-related brain trajectories in schizophrenia: a systematic review of structural MRI studies

Using the Pubmed database, we performed a detailed literature search for structural magnetic resonance imaging studies on patients with schizophrenia, investigating the relationship between macroscopic and microscopic structural parameters and age, to delineate an age-related trajectory. Twenty-six studies were considered for the review, from January 2000 to June 2012. Research results are heterogeneous because of the multifactorial features of schizophrenia and the multiplicity of the methodological approaches adopted. Some areas, within the amygdala-hippocampus complex, which are affected early in life by schizophrenia, age in a physiological way. Other regions, such as the superior temporal gyrus, appear already impaired at the onset of symptoms, undergo a worsening in the acute phase but later stabilize, progressing physiologically over years. Finally, there are regions, such as the uncinate fasciculus, which are not altered early in life, but are affected around the onset of schizophrenia, with their impairment continuously worsening over time. Further extensive longitudinal studies are needed to understand the timing and the possible degenerative characteristics of structural impairment associated with schizophrenia.

Progressive brain changes in schizophrenia related to antipsychotic treatment? A meta-analysis of longitudinal MRI studies

Context

Antipsychotic treatment is the first-line treatment option for schizophrenia. Individual studies suggested they can significantly affect brain structure and account for progressive brain changes observed during the illness.

Objectives

To quantitatively examine the effect of antipsychotics as compared to illness related factors on progressive brain changes in schizophrenia.

Data sources

Electronic databases were searched until April 2012. All magnetic resonance imaging studies reporting progressive brain changes in schizophrenia subjects and antipsychotic exposure were retrieved.

Study selection

30 longitudinal MRI studies with antipsychotic administration in schizophrenia patients met the inclusion criteria.

Data extraction

Brain volumes before and after antipsychotic exposure, duration of illness, severity of psychotic symptoms as well as demographic, clinical, and methodological variables were extracted from each publication, or obtained directly from its authors.

Data synthesis

The overall sample was of 1046 schizophrenia patients and 780 controls for a median duration of follow-up of 72.4 weeks. At baseline, patients showed significant whole brain volume reductions and enlarged lateral ventricle (LV) volumes compared to controls. No baseline volumetric abnormalities were detected in the gray matter volumes (GMV), white matter volumes, cerebrospinal fluid and caudate nucleus. Longitudinally, there were progressive GMV decreases and LV enlargements in patients but not in controls. The GMV decreases were inversely correlated with cumulative exposure to antipsychotic treatments, while no effects were observed for duration of illness or illness severity.

Conclusions

Schizophrenia is characterized by progressive gray matter volume decreases and lateral ventricular volume increases. Some of these neuroanatomical alterations may be associated with antipsychotic treatment.

A 5-year follow-up study of brain cortical and subcortical abnormalities in a schizophrenia cohort

BACKGROUND

Magnetic resonance imaging studies have demonstrated that patients with schizophrenia have thinner cortex in prefrontal and temporal brain regions, and enlarged lateral ventricles, compared to healthy subjects. Longitudinal studies have shown progressive brain tissue loss and ventricular dilatation among patients, predominantly in the early phase of the illness. Evidence for progression in more chronic phases of schizophrenia is less established.

METHODS

Measurements of cortical thickness, cortical volume and subcortical volumes were obtained from 52 patients with long-term treated schizophrenia and 63 healthy subjects who were scanned twice over five years. Differences in brain measurements across time and group were investigated using general linear models.

RESULTS

Compared to controls, patients had similar patterns of thinner cortex and smaller cortical volumes in prefrontal and temporal regions at both time points. In the follow-up interval regional cortical volumes decreased and lateral ventricle volumes increased in both groups. There was a trend level interaction effect of group and time for the right lateral ventricle, but not for cortical measurements. This effect was related to higher degree of negative symptoms at follow-up.

CONCLUSIONS

Regional differences in cortical thickness and volume between long-term treated patients with schizophrenia and healthy subjects are stable across five years, while right lateral ventricle volumes tend to increase more in the patients. The findings indicate that brain structure abnormalities found in schizophrenia are not progressive in the chronic stage of the disease, but that some progression in subcortical structures may be present in patients with poor outcome.

Confounders of excessive brain volume loss in schizophrenia

There is convincing evidence that schizophrenia is characterised by progressive brain volume changes during the course of the illness. In a large longitudinal study it was shown that different age-related trajectories of brain tissue loss are present in patients compared to healthy subjects, suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. However, studies show that medication intake and cannabis use are important confounding factors when interpreting brain volume (change) abnormalities. Indeed, continues use of cannabis, but not cigarette smoking, is associated to a more pronounced loss of grey matter in the anterior cingulated and the prefrontal cortex. Atypical antipsychotics have been found to be related to smaller decreases in tissue loss. Moreover, independent of antipsychotic medication intake, the brain volume abnormalities appear associated to the outcome of the illness.

The course of brain abnormalities in schizophrenia: can we slow the progression?

There is convincing evidence that schizophrenia is characterized by progressive brain volume changes during the course of the illness. In a large longitudinal study it was shown that different age-related trajectories of brain tissue loss are present in patients compared with healthy subjects, suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. Studies show that medication intake is an important confounding factor when interpreting brain volume (change) abnormalities. Atypical antipsychotics have been found to be related to smaller decreases in tissue loss. Moreover, independent of antipsychotic medication intake, the brain volume abnormalities appear associated to the outcome of the illness. Before being able to intervene with therapies and prevent the brain from shrinking, one has to understand the underlying mechanism of the progressive changes in the brains of schizophrenia patients.

One year longitudinal study of the straight gyrus morphometry in first-episode schizophrenia-spectrum patients

The aim of this study was to use a region-of-interest approach with magnetic resonance imaging to examine the volume of the straight gyrus volume change in first-episode schizophrenia-spectrum patients compared with healthy subjects over a 1-year follow-up period. We did not find a differential pattern of volumetric change between the two groups.

Neuroimaging and treatment evidence for clinical staging in psychotic disorders: from the at-risk mental state to chronic schizophrenia

A new approach to understanding severe mental disorders such as schizophrenia is to adopt a clinical staging model. Such a model defines the extent of the illness such that earlier and milder phenomena are distinguished from later, more impairing features. Specifically, a clinical staging model makes three key predictions. First, pathologic measures should be more abnormal in more severe stages. Second, patients who progress between the stages should show change in these same pathologic measures. Finally, treatment should be more effective in the earlier stages, as well as more benign. In this article, we review the evidence for these three predictions from studies of psychotic disorders, with a focus on neuroimaging data. For all three, the balance of evidence supports the predictions of the staging model. However, there are a number of alternative explanations for these findings, including the effects of medication and symptom heterogeneity.

Lack of progression of brain abnormalities in first-episode psychosis: a longitudinal magnetic resonance imaging study

BACKGROUND

Some neuroimaging studies have supported the hypothesis of progressive brain changes after a first episode of psychosis. We aimed to determine whether (i) first-episode psychosis patients would exhibit more pronounced brain volumetric changes than controls over time and (ii) illness course/treatment would relate to those changes.

METHOD

Longitudinal regional grey matter volume and ventricle:brain ratio differences between 39 patients with first-episode psychosis (including schizophrenia and schizophreniform disorder) and 52 non-psychotic controls enrolled in a population-based case-control study.

RESULTS

While there was no longitudinal difference in ventricle:brain ratios between first-episode psychosis subjects and controls, patients exhibited grey matter volume changes, indicating a reversible course in the superior temporal cortex and hippocampus compared with controls. A remitting course was related to reversal of baseline temporal grey matter deficits.

CONCLUSIONS

Our findings do not support the hypothesis of brain changes indicating a progressive course in the initial phase of psychosis. Rather, some brain volume abnormalities may be reversible, possibly associated with a better illness course.

Study factors influencing ventricular enlargement in schizophrenia: a 20 year follow-up meta-analysis

A meta-analysis was performed on studies employing the ventricular-brain ratio to compare schizophrenic subjects to that of normal controls. This was a follow-up to a similar meta-analysis published in 1992 in which study-, in addition to clinical-, factors were found to contribute significantly to the reported difference between patients with schizophrenia and controls. Seventy-two (N=72) total studies were identified from the peer reviewed literature, 39 from the original meta-analysis, and 33 additional studies published since which met strict criteria for inclusion and analysis - thus representing ~30 years of schizophrenia ventricular enlargement research. Sample characteristics from schizophrenics and controls were coded for use as predictor variables against within sample VBR values as well as for between sample VBR differences. Additionally, a number of factors concerning how the studies were conducted and reported were also coded. Obtained data was subjected to unweighted univariate as well as multiple regression analyses. In particular, results indicated significant differences between schizophrenics and controls in ventricular size but also the influence of the diagnostic criteria used to define schizophrenia on the magnitude of the reported VBR. This suggests that differing factors of the diagnostic criteria may be sensitive to ventricular enlargement and might be worthy of further examination. Interestingly, we observed an inverse relationship between VBR difference and the number of co-authors on the study. This latter finding suggests that larger research groups report smaller VBR differences and may be more conservative or exacting in their research methodology. Analyses weighted by sample size provided identical conclusions. The effects of study factors such as these are helpful for understanding the variation in the size of the reported differences in VBR between patients and controls as well as for understanding the evolution of research on complex clinical syndromes employing neuroimaging morphometrics.

Effect of chronic antipsychotic treatment on brain structure: a serial magnetic resonance imaging study with ex vivo and postmortem confirmation

BACKGROUND

There is increasing evidence that antipsychotic (APD) may affect brain structure directly. To examine this, we developed a rodent model that uses clinically relevant doses and serial magnetic resonance imaging (MRI), followed by postmortem histopathological analysis to study the effects of APD on brain structures.

METHODS

Antipsychotic , haloperidol, and olanzapine were continuously administered to rats via osmotic minipumps to maintain clinic-like steady state levels for 8 weeks. Longitudinal in vivo MRI scanning (T₂-weighted) was carried out at baseline, 4 weeks, and 8 weeks, after which animals were perfused and their brains preserved for ex vivo MRI scanning. Region of interest analyses were performed on magnetic resonance images (both in vivo as well as ex vivo) along with postmortem stereology using the Cavalieri estimator probe.

RESULTS

Chronic (8 weeks) exposure to both haloperidol and olanzapine resulted in significant decreases in whole-brain volume (6% to 8%) compared with vehicle-treated control subjects, driven mainly by a decrease in frontal cerebral cortex volume (8% to 12%). Hippocampal, corpus striatum, lateral ventricles, and corpus callosum volumes were not significantly different from control subjects, suggesting a differential effect of APD on the cortex. These results were corroborated by ex vivo MRI scans and decreased cortical volume was confirmed postmortem by stereology.

CONCLUSIONS

This is the first systematic whole-brain MRI study of the effects of APD, which highlights significant effects on the cortex. Although caution needs to be exerted when extrapolating results from animals to patients, the approach provides a tractable method for linking in vivo MRI findings to their histopathological origins.

A systematic review of the effects of antipsychotic drugs on brain volume

BACKGROUND

People with schizophrenia are often found to have smaller brains and larger brain ventricles than normal, but the role of antipsychotic medication remains unclear.

METHOD

We conducted a systematic review of magnetic resonance imaging (MRI) studies. We included longitudinal studies of brain changes in patients taking antipsychotic drugs and we examined studies of antipsychotic-naive patients for comparison purposes.

RESULTS

Fourteen out of 26 longitudinal studies showed a decline in global brain or grey-matter volume or an increase in ventricular or cerebrospinal fluid (CSF) volume during the course of drug treatment, including the largest studies conducted. The frontal lobe was most consistently affected, but overall changes were diffuse. One large study found different degrees of volume loss with different antipsychotics, and another found that volume changes were associated with taking medication compared with taking none. Analyses of linear associations between drug exposure and brain volume changes produced mixed results. Five out of 21 studies of patients who were drug naive, or had only minimal prior treatment, showed some differences from controls in volumes of interest. No global differences were reported in three studies of drug-naive patients with long-term illness. Studies of high-risk groups have not demonstrated differences from controls in global or lobar brain volumes.

CONCLUSIONS

Some evidence points towards the possibility that antipsychotic drugs reduce the volume of brain matter and increase ventricular or fluid volume. Antipsychotics may contribute to the genesis of some of the abnormalities usually attributed to schizophrenia.

Progressive lateral ventricular enlargement in schizophrenia: a meta-analysis of longitudinal MRI studies

BACKGROUND

Lateral ventricular enlargement is one of the most consistent findings in patients with schizophrenia; however whether progressive ventricular dilation occurs during the course of the illness has been controversial. To clarify this we conducted a meta-analysis of longitudinal studies measuring the lateral ventricles in patients with schizophrenia and a control group.

METHODS

The MEDLINE database was searched from 1980 to 2009 for longitudinal MRI studies of patients with schizophrenia. We identified 13 studies that measured the lateral ventricles in both patients and controls and these were included in a random effects meta-analysis. The effect of various clinical variables was investigated in a meta-regression analysis.

RESULTS

Patients showed evidence of progressive ventricular enlargement after illness onset greater than that seen in controls (effect size=0.45, 95%CI 0.19-0.71, p=0.0006). A sub-analysis of chronic patients with schizophrenia with a mean duration of illness of 7.6 years at baseline scan also showed progressive ventricular enlargement (p=0.002). The results were robust to inclusion criteria, and no significant effect of age of onset, duration of illness, or age at baseline scan, was found in the meta-regression analysis.

CONCLUSIONS

The meta-analysis shows progressive changes in ventricular volume a number of years after illness onset and challenges an exclusively neurodevelopmental model of schizophrenia.

Do antipsychotic drugs affect brain structure? A systematic and critical review of MRI findings

BACKGROUND

The potential effects of antipsychotic drugs on brain structure represent a key factor in understanding neuroanatomical changes in psychosis. This review addresses two issues: (1) do antipsychotic medications induce changes in total or regional human brain volumes and (2) do such effects depend on antipsychotic type?

METHOD

A systematic review of studies reporting structural brain magnetic resonance imaging (MRI) measures: (1) directly in association with antipsychotic use; and (2) in patients receiving lifetime treatment with antipsychotics in comparison with drug-naive patients or healthy controls. We searched Medline and EMBASE databases using the medical subject heading terms: 'antipsychotics' AND 'brain' AND (MRI NOT functional). The search included studies published up to 31 January 2007. Wherever possible, we reported the effect size of the difference observed.

RESULTS

Thirty-three studies met our inclusion criteria. The results suggest that antipsychotics act regionally rather than globally on the brain. These volumetric changes are of a greater magnitude in association with typical than with atypical antipsychotic use. Indeed, there is evidence of a specific effect of antipsychotic type on the basal ganglia, with typicals specifically increasing the volume of these structures. Differential effects of antipsychotic type may also be present on the thalamus and the cortex, but data on these and other brain areas are more equivocal.

CONCLUSIONS

Antipsychotic treatment potentially contributes to the brain structural changes observed in psychosis. Future research should take into account these potential effects, and use adequate sample sizes, to allow improved interpretation of neuroimaging findings in these disorders.

Progressive gray matter changes in first episode schizophrenia: a 4-year longitudinal magnetic resonance study using VBM

Schizophrenia is a disabling illness, characterized by a heterogeneous course including clinical deterioration and poor outcome. Accumulating findings in schizophrenia suggest that it might involve two pathophysiologic processes, one early in life (neurodevelopmental), and one after onset of the illness (neurodegenerative). Longitudinal imaging studies after onset of the illness may help to clarify these pathophysiological aspects of schizophrenia, but so far, probably due to methodological differences, there have been no conclusive results. The present study sets out to investigate longitudinal gray matter changes in patients with first-episode schizophrenia relative to healthy subjects over the first 4 years of the illness and the relation of gray matter changes in patients with functional outcome, using an objective automatic method not biased to one particular structure to analyze gray matter changes.

METHODS

We included 28 first-episode neuroleptic-naïve patients with DSM-IV diagnosis of schizophreniform disorder or schizophrenia, and 17 controls. 15 patients and 11 controls completed the longitudinal study and were reevaluated after four years. Gray matter changes over time were measured with voxel-based morphometry (VBM) using SPM5. Functional outcome was measured with the global assessment functioning scale (GAF).

RESULTS

Excessive decrease in gray matter was found in patients as compared to healthy individuals in the left superior temporal gyrus and right orbitofrontal gyrus, and excessive increase in the bilateral lingual gyrus and right cuneus. Additionally, gray matter changes in patients in the left lingual gyrus, right insula and right cerebellum, were inversely related to functional outcome (p<0.001 uncorrected at voxel level, p<0.05 family-wise-error corrected at cluster level).

CONCLUSIONS

There are differing longitudinal gray matter changes in patients with schizophrenia during the first years of the illness as compared to healthy individuals. Some progressive gray matter changes in patients are related to functional outcome.

Workshop on defining the significance of progressive brain change in schizophrenia: December 12, 2008 American College of Neuropsychopharmacology (ACNP) all-day satellite, Scottsdale, Arizona. The rapporteurs' report

In 1990 a satellite session of the American College of Neuropsychopharmacology (ACNP) Annual Meeting was held that focused on the question of whether progressive changes in brain structure occur in schizophrenia and this session raised considerable controversy. Eighteen years later, on December 12, 2008, after much data have since accumulated on this topic, a group of approximately 45 researchers gathered after the annual ACNP meeting to participate in a similar workshop on several unresolved questions still remaining: (1) How strong and consistent is the evidence? (2) Is there anatomic specificity to changes and is it disease specific or subject specific? (3) What is the time course? (4) What is the underlying pathophysiology (i.e. is it central to the disease process or is it due to neuroleptic treatment or other epiphenomena? (5) What is its clinical significance? and (6) Are there treatment implications? The day was chaired by Lynn E. DeLisi and co-chaired by Stephen J. Wood. Christos Pantelis and Jeffrey A. Lieberman extensively helped with its planning. The ACNP assisted in its organization as an official satellite of its annual meeting and several pharmaceutical companies provided support with unrestricted educational grants. The following is a summary of the sessions as recounted by rapporteurs whose job was to record as closely as possible the outcome of discussions on the above outlined questions.

Optimization of the SNR-resolution tradeoff for registration of magnetic resonance images

Image registration serves many applications in medical imaging, including longitudinal studies, treatment verification, and more recently, morphometry. Registration processing is regularly applied in magnetic resonance (MR) images, where imaging is highly adaptable in capturing soft tissue contrast. To obtain the greatest registration accuracy in MR imaging, the inherent imaging tradeoff between SNR and resolution at a given scan time should be optimized for computational accuracy, rather than human viewing. We investigated this SNR-resolution tradeoff to optimize registration for digital morphometry. Tradeoff images were simulated from acquired gold standard MR images to emulate a shorter, constant acquisition time, but at the expense of SNR, resolution, or both. The group of images from each tradeoff was nonlinearly registered toward an average atlas producing deformation fields, useful for identifying differences in morphology. The gold standard data were also registered. The deformation fields were used to evaluate registration performance of each tradeoff relative to the gold standard. For fixed scan times, the optimal SNR for registration with MR imaging was found to be approximately 20. Image resolution should be adjusted to produce this target voxel SNR when registration is a central processing task.

The concept of progressive brain change in schizophrenia: implications for understanding schizophrenia

Kraepelin originally defined dementia praecox as a progressive brain disease, although this concept has received various degrees of acceptance and rejection over the years since his famous published textbooks appeared. This article places an historical perspective on the current renewal of Kraepelin's concept in brain imaging literature that supports progressive brain change in schizophrenia from its earliest stages through its chronic course. It is concluded that a great deal of future research is needed focusing on the longitudinal course of change, the extent to the regions of change within each individual and the underlying mechanism and implications of brain change through functional and neurochemical imaging, combined with structural studies in the same individuals.

Investigating the neuropsychological and neuroanatomical changes that occur over the first 2-3 years of illness in patients with first-episode schizophrenia

OBJECTIVE

This study explored the concurrent courses of the neuroanatomical and neuropsychological changes that occurred over the first 2-3 years of illness in patients with first-episode schizophrenia (FES).

METHODS

Fifty-two patients with FES underwent neuropsychological testing and a structural magnetic resonance imaging (sMRI) scan within three months of their first presentation to mental health services with psychotic symptoms (time1). Patients' cognitive performance was evaluated via an extensive neuropsychological test battery, which assessed 9 cognitive domains. Of the 52 patients at time1, 32 returned 2-3 years later (time2) for follow-up neuropsychological testing, and 20 of these also underwent follow-up sMRI. MR images were preprocessed in SPM99. Grey matter volumes of patients' whole-brain, frontal lobes and temporal lobes were calculated by convolving the preprocessed images with manually-drawn binary masks.

RESULTS

Patients exhibited longitudinal improvements in full-scale IQ, performance IQ and visual memory. In contrast, concurrent reductions in grey matter were observed for the whole-brain (3% reduction) and the frontal lobe (3.65% reduction). Furthermore, the extent of patients' whole-brain and frontal-lobe grey matter changes were positively correlated with longitudinal changes in verbal learning and memory.

DISCUSSION

The results of this study suggest that while the early stages of schizophrenia are associated with a mild improvement in patients' overall cognitive functioning, they are also associated with progressive grey matter atrophy.

Progressive brain volume loss in schizophrenia over the course of the illness: evidence of maturational abnormalities in early adulthood

BACKGROUND

Considering the magnitude of the reported changes in brain volume over time in first-episode patients it is unlikely that these changes are constant over the life-span of the schizophrenic illness. Thus, one would expect the progression in brain volume change in schizophrenia to follow a more complex trajectory over time.

METHODS

Two magnetic resonance imaging brain scans were obtained over a 5-year interval of 96 schizophrenia patients and 113 healthy subjects between ages 16 to 56.

RESULTS

The trajectory of brain volume change differed between patients with schizophrenia and healthy individuals. Before the age of 45 years cerebral and gray matter loss and lateral ventricle increase were excessive in patients relative to controls, representing approximately the first 20 years of illness. Patients showed an excessive third ventricle volume increase over time. In addition, poor outcome patients showed more brain tissue loss during the follow-up interval than good outcome patients.

CONCLUSIONS

Cerebral (gray) matter volume loss in the patients was mainly characterized by the absence of the normal curved trajectory of volume change with age that was present in healthy subjects. Later in life, the degree of volume change in patients is similar to that observed with normal aging. Independently of age, larger brain volume changes appear clinically relevant.

Dominant-negative DISC1 transgenic mice display schizophrenia-associated phenotypes detected by measures translatable to humans

Here, we report generation and characterization of Disrupted-In-Schizophrenia-1 (DISC1) genetically engineered mice as a potential model for major mental illnesses, such as schizophrenia. DISC1 is a promising genetic risk factor for major mental illnesses. In this transgenic model, a dominant-negative form of DISC1 (DN-DISC1) is expressed under the alphaCaMKII promoter. In vivo MRI of the DN-DISC1 mice detected enlarged lateral ventricles particularly on the left side, suggesting a link to the asymmetrical change in anatomy found in brains of patients with schizophrenia. Furthermore, selective reduction in the immunoreactivity of parvalbumin in the cortex, a marker for an interneuron deficit that may underlie cortical asynchrony, is observed in the DN-DISC1 mice. These results suggest that these transgenic mice may be used as a model for schizophrenia. DN-DISC1 mice also display several behavioral abnormalities, including hyperactivity, disturbance in sensorimotor gating and olfactory-associated behavior, and an anhedonia/depression-like deficit.

CSF sub-compartments in relation to plasma osmolality in healthy controls and in patients with first episode schizophrenia

Preliminary evidence suggests that plasma Na(+) level/osmolality may have effects on brain morphology; thus we investigated the link between plasma osmolality and ventricle size in healthy controls and patients with first episode schizophrenia. A total of 16 patients and 28 healthy controls were examined with magnetic resonance imaging (MRI) and gave blood samples. High-resolution 3D SPGR images were obtained on a 1.5 Tesla scanner. Scalp-edited MRI volumes were used for estimates of intracranial gray, white matter and CSF. Regional changes in CSF concentration and ventricular morphology were measured. The groups did not differ in plasma osmolality, but patients had higher plasma Na(+). There were no differences in ventricle size. Controlling for plasma osmolality did not change the results. A mixed model procedure indicated a significant group effect and a significant osmolality by group interaction in ventricle measures. Healthy control group showed a significant relationship between osmolality and ventricle measures; this relationship was absent in the patients. Significant correlations between osmolality and lateral ventricle surface deformations were observed along the superior horn of the lateral ventricles in the healthy controls. These results suggest that plasma osmolality is related to ventricle size in healthy volunteers and that this physiological link is impaired in patients with first episode schizophrenia.

Application of three-dimensional magnetic resonance image registration for monitoring hip joint diseases

The purpose of this study was to estimate the accuracy of a method in which three-dimensional (3D) magnetic resonance (MR) volume registration is used for monitoring hip joint disease. Data were analyzed using a normalized cross-correlation (NCC) algorithm involving a user-selected 3D box including the proximal femur. Most of the femoral head was not included in the 3D box because it can become deformed during the course of disease. The accuracy of registration around the femoral head was evaluated using five phantoms and clinical MR data of 17 patients with hip joint disease. In the phantom experiment, registration accuracy was evaluated using four fiducial markers attached to the femoral head. In the experiment using clinical data, registration accuracy was evaluated using a landmark in the femoral head. The registration accuracy in the phantom and clinical experiment was 0.43+/-0.18 mm (S.D.) and 1.12+/-0.46 mm (S.D.), respectively. The former is a value less than half the minimum dimension of a voxel (1.25 x 1.25 x 1.0 mm). Although the latter is slightly larger than the minimum dimension of a voxel, actual errors would be smaller because of the uncertainty in landmark localization. In conclusion, the present method based on an NCC algorithm can be used to accurately register serial MR images of the femoral heads with an error on the order of a voxel. We believe that this method is sufficiently accurate for monitoring hip joint diseases.

A volumetric MRI and magnetization transfer imaging follow-up study of patients with first-episode schizophrenia

Conventional MRI studies have not provided definitive evidence of progressive loss of brain volume in the early stages of schizophrenia, although more subtle changes may have gone undetected. We have looked for such subtle changes using volumetric MRI and magnetization transfer imaging (MTI), an advanced MRI technique sensitive to subtle neuropathological abnormalities. Magnetization transfer images and high-resolution volumetric T1-weighted images were acquired from 16 patients with first-episode schizophrenia at the start of the study and 3.7 years later. A group of 12 healthy controls were also scanned on two occasions. Images were processed using a voxel-based approach that allows whole-brain analysis. There was a group difference with a significant volume loss in the patients' white matter adjacent to the lateral ventricles in the right and left temporal lobes, in medial temporal gyrus, and in the white matter in and around the right middle frontal gyrus. No cortical differences were detected between the groups using MTI or volumetric MRI. The absence of any time-by-group interaction suggests that these abnormalities do not progress in the early stages of the disease. The results of the study need to be interpreted in the light of the small sample size and of the limitations of current image analysis methods.

Brain volume in first-episode schizophrenia: systematic review and meta-analysis of magnetic resonance imaging studies

BACKGROUND

Studies of people with schizophrenia assessed using magnetic resonance imaging (MRI) usually include patients with first-episode and chronic disease, yet brain abnormalities may be limited to those with chronic schizophrenia.

AIMS

To determine whether patients with a first episode of schizophrenia have characteristic brain abnormalities.

METHOD

Systematic review and meta-analysis of 66 papers comparing brain volume in patients with a first psychotic episode with volume in healthy controls.

RESULTS

A total of 52 cross-sectional studies included 1424 patients with a first psychotic episode; 16 longitudinal studies included 465 such patients. Meta-analysis suggests that whole brain and hippocampal volume are reduced (both P<0.0001) and that ventricular volume is increased (P<0.0001) in these patients relative to healthy controls.

CONCLUSIONS

Average volumetric changes are close to the limit of detection by MRI methods. It remains to be determined whether schizophrenia is a neurodegenerative process that begins at about the time of symptom onset, or whether it is better characterised as a neurodevelopmental process that produces abnormal brain volumes at an early age.

Mr morphometry analysis of grey matter volume reduction in schizophrenia: association with hallucinations

The authors used voxel-based morphometry (VBM) to study GM volume differences in the whole brain volume between a group of patients with schizophrenia and a healthy control group. There were 12 patients and 12 control subjects. The subjects were scanned in a 1.5 T MR scanner. The patients had all been evaluated by a senior psychiatrist on the brief psychiatric rating scale (BPRS). The VBM data was correlated with reports of rate and frequency of hallucinations based on their scores on the BPRS hallucination item. There were significant grey matter volume reductions in the schizophrenia patient group in the left superior (transverse) temporal gyrus, the left middle frontal gyrus, and in the right cuneus. Areas of grey matter volume reduction that correlated negatively with hallucinations were found in the left superior (transverse) temporal gyrus, left thalamus, and left and right cerebellum. This article proposes that significant reductions in grey matter volume may be instrumental in generating spontaneous neuronal activity that is associated with speech perception experiences in the absence of an external acoustic stimulus that may cause hallucinations.

Brain morphology in first-episode schizophrenia: a meta-analysis of quantitative magnetic resonance imaging studies

BACKGROUND

A number of meta-analytic reviews of structural brain imaging studies have shown that multiple subtle brain abnormalities are consistently found in schizophrenia. However, quantitative reviews till now published have included mainly studies performed on chronic schizophrenic patients but have failed to provide clear information on specific, possibly different, findings in first-episode schizophrenia.

METHODS

We performed a systematic search for MRI studies that reported quantitative measurements of volumes of brain regions in first-episode schizophrenic patients and in healthy controls. Twelve meta-analyses were performed for 6 cerebral regions.

RESULTS

Twenty-one studies were identified as suitable for analysis. Significant overall effect sizes were demonstrated for lateral and third ventricular volume increase, and for volume reduction of whole brain and hippocampus, but not for temporal lobe, amygdala and total intracranial volumes.

CONCLUSIONS

The available literature data strongly indicate that some brain abnormalities are already present in first-episode schizophrenic patients. However, unlike the results of published meta-analyses conducted primarily on samples of chronic schizophrenic patients, the present study did not confirm a significant reduction of temporal lobe or amygdala volumes in first-episode schizophrenia. These findings support the hypothesis of different patterns of involvement of various cerebral areas over the time course of schizophrenia.

Regional specificity of cerebrospinal fluid abnormalities in first episode schizophrenia

The timing and regional specificity of cerebrospinal fluid (CSF) enlargements have not been well described in schizophrenia. High-resolution magnetic resonance images and computational image analysis methods were used to localize cross-sectional changes in lateral ventricle and sulcal and subarachnoid CSF in first episode schizophrenia patients (51 males/21 females) and healthy subjects (37 males/41 females). Volumes were obtained for each lateral ventricle horn and regional differences identified by comparing the distances from the ventricular surfaces to the central core at anatomically matched locations. Extra-cortical CSF differences were compared by measuring the proportion of CSF voxels sampled from spatially homologous cortical surface points. Significant extra-cortical CSF enlargements were observed in first episode patients, where regional differences surrounded the temporal, anterior frontal and parietal cortices. Volume and ventricular surface analyses failed to show significant effects of diagnosis. However, interactions indicated dorsal superior horn expansions in female patients compared with same-sex controls. Since ventricular enlargements are widely reported in chronic patients, our observations at first episode suggest ventricular enlargement may progress after disease onset with early changes occurring around the dorsal superior horn. In contrast, sulcal and subarachnoid CSF increases may be manifest near or before the first episode but after brain development is complete, reflecting pronounced reductions in proximal brain tissue.

Longitudinal volumetric MRI study in first- and multiple-episode male schizophrenia patients

In this longitudinal study we compared brain volume changes in first- and multiple-episode patients with schizophrenia to normal aging changes observed in healthy control subjects scanned at comparable times. Two to four years after an initial examination including MRI volumetry, we followed up 21 first episode patients, 17 patients after multiple episodes of schizophrenia, and 20 healthy controls. Volumetric measurements of left and right hemispheres, total brain volume, lateral ventricles, hippocampus and amygdala as well as a clinical evaluation were performed. Patients with schizophrenia showed significant ventricular enlargement and volume reduction of the hippocampus-amygdala complex compared with healthy control subjects both at baseline and follow-up. While there were no differences between patients and controls with respect to mean annual volume changes in the measured regions, patients with schizophrenia showed higher between-subject variability in ventricular volume change. These data are consistent with cross-sectional studies demonstrating ventricular enlargement and hippocampal volume deficits in schizophrenia. However, we were not able to demonstrate a difference in the rate of volume changes over time that distinguished patients with schizophrenia from healthy controls for any of the brain structures measured. Drawbacks of the study are that the follow-up was done after a relatively short interval and that there was a difference in time to follow-up and age between patients and controls. Our results do not support the hypothesis that schizophrenia leads to progressive volume reduction in these areas, although there may be a subset of patients with morphologically visible disease progression.

Schizophrenia syndromes associated with changes in ventricle-to-brain ratios: a serial high-resolution three-dimensional magnetic resonance imaging study in first-episode schizophrenia patients using subvoxel registration and semiautomated quantification

A cohort of patients with first-episode schizophrenia was dichotomised into two age- and sex-matched groups of clinical syndromes, the active and withdrawn, and underwent high-resolution three-dimensional magnetic resonance imaging at baseline and 8 months later. A cohort of age- and sex-matched normal controls was also imaged at the same time intervals. The application of subvoxel registration and semiautomated quantification techniques demonstrated a significantly different outcome in ventricular changes between the two groups of patients. Compared with the controls, the withdrawn patients showed progressive ventricular enlargement, with an increase in ventricle-to-brain volume ratio, whereas the active group showed a reduction in ventricle-to-brain volume ratio, with a change opposite in sign and smaller in magnitude. These findings lend further support for the aetiological validity of this syndromal model of schizophrenia and are likely to be of importance in furthering our understanding of its pathogenesis and in the development of suitable therapeutic strategies.

Ver�nderungen der Hirnstruktur durch neuroleptische Medikation

A couple of studies showed that neuroleptic treatment affects brain morphology. This paper reviews findings of volumetric longitudinal studies on treated schizophrenics, longitudinal studies considering the effect of different neuroleptic treatments on brain morphology, and studies on neuroleptic-naive patients with schizophrenia. The latter studies show enlargement of ventricles, diminished volume of the thalamus and reduced gray matter in different cortical regions. Findings on the nucleus caudatus, hippocampus, and amygdala are inconsistent. The volumes of the putamen and globus pallidus are unchanged. Medication with typical antipsychotics leads to increased volume of the nucleus caudatus while atypical antipsychotics do not change the volume of the nucleus caudatus.

Lower prefrontal gray matter volume in schizophrenia in chronic but not in first episode schizophrenia patients

Although a lower volume of prefrontal (PF) gray matter (GM) in patients with schizophrenia than in normal control subjects is a replicated finding, it is not yet clear whether this finding is present at the onset of illness. Clinical and imaging data suggest that the reduction in PF GM becomes apparent only some years following the onset of illness. To test this hypothesis, we used magnetic resonance imaging to study PF GM and sulcal cerebrospinal fluid (CSF) volumes in 81 schizophrenic patients. A Talairach-based tool was used for segmentation. Subjects included 44 healthy controls, 22 first-episode (FE), treatment-naïve patients with duration of illness of less than 1 year; 29 short-term chronic (SC) patients with durations of illness between 1.5 and 6 years; and 30 long-term chronic (LC) patients with duration of illness of more than 6 years. The data from healthy controls were used to calculate volume residuals in the patients, defined as deviations from the expected values given individual age and intracranial volume. The FE group did not show significant differences in GM or in CSF volumes compared with controls. However, both the SC and the LC patients showed the expected pattern of lower values for PF GM and an excess of PF sulcal CSF compared with controls. There were no significant differences between SC and LC patients in any of these measurements. There was a significant and inverse association between duration of illness and GM residuals. That association fit a nonlinear rather than a linear model, which was consistent with a decrease of GM volume during the first years following illness onset. No significant differences were found between those receiving atypical and typical antipsychotic drugs during the previous year.

Eicosapentaenoic acid-rich essential fatty acid supplementation in chronic fatigue syndrome associated with symptom remission and structural brain changes

Lateral ventricular enlargement has been reported in chronic fatigue syndrome, while cerebral neurospectroscopy has recently indicated that essential fatty acid treatment may be of value in this condition. An essential fatty acid supplement rich in eicosapentaenoic acid (EPA) was therefore given daily to a female patient with a 6-year history of unremitting symptoms of chronic fatigue syndrome. Cerebral magnetic resonance scanning was carried out at baseline and 16 weeks later. The EPA-rich essential fatty acid supplementation led to a marked clinical improvement in her symptoms of chronic fatigue syndrome, starting within 6-8 weeks. Accurate quantification of the lateral ventricular volumes in the baseline and 16-week follow-up registered images of high-resolution magnetic resonance imaging structural scans showed that the treatment was accompanied by a marked reduction in the lateral ventricular volume during this period, from 28,940-23,660 mm3.

Brain volumes as predictor of outcome in recent-onset schizophrenia: a multi-center MRI study

Gray matter brain volume decreases have been found in patients with schizophrenia as compared to healthy control subjects measured by using Magnetic Resonance Imaging (MRI). An association has been suggested between decreased gray matter volume and poor outcome in chronically ill patients with schizophrenia. The present longitudinal multi-center study investigated whether gray matter volume at illness onset can predict poor outcome in recent-onset schizophrenia after a follow-up of approximately 2 years. An MRI calibration study was performed since scans of patients with recent-onset psychosis were conducted at three sites with 1.5 T MR scanners from two different manufacturers. Applying a linear scaling procedure on the histogram improved comparability between volume measurements acquired from images from the different scanners. Brain scans were obtained from 109 patients with recent-onset schizophrenia. Volumes of intracranium, total brain, cerebral gray and white matter, third and lateral ventricles, and cerebellum were measured. After a mean follow-up period of approximately 2 years, measurements of symptoms, functioning, need for care, and illness history variables were assessed. No significant correlations were found between the brain volume measures and any of these measures. Gray matter volume at illness onset does not predict outcome after 2 years in recent-onset schizophrenia.

Brain volume, asymmetry and intellectual impairment in relation to sex in early-onset schizophrenia

BACKGROUND

Accumulating evidence suggests that early-onset schizophrenia arises from a disturbance in the normal trajectory of cerebral development.

AIMS

To investigate brain structure, asymmetry and IQ in early-onset schizophrenia.

METHOD

Volumes of left and right cerebral hemispheres and IQ were assessed in 33 participants with early-onset DSM-IV schizophrenia and 30 members of a matched, normal control group.

RESULTS

Total brain volume was significantly smaller in the group with early-onset disease ('cases') relative to the control group (4.5%), especially for the left hemisphere in males (6.0%). A significant sex x diagnosis interaction in hemisphere asymmetry revealed that the female cases group had significantly reduced rightward asymmetry relative to the female control group and that the male cases tended to have reduced leftward asymmetry relative to the male control group. Decreased left hemisphere volume in males and decreased rightward hemispheric asymmetry in females correlated with reduced IQ.

CONCLUSIONS

Sexually dimorphic alterations in asymmetry correlate with degree of intellectual impairment in early-onset schizophrenia.

Evaluation of software for registration of contrast-enhanced brain MR images in patients with glioblastoma multiforme

OBJECTIVE

We evaluated commercially available software that rapidly and automatically registers brain MR images on a clinical workstation, and we studied the accuracy of these registrations.

SUBJECTS AND METHODS

Ten patients with a diagnosis of glioblastoma multiforme underwent contrast-enhanced inversion recovery prepared three-dimensional (3D) volumetric spoiled gradient-recalled acquisition in the steady state (SPGR) MR imaging (contiguous 1.5-mm slice thickness, 96-104 slices). After this imaging sequence, each patient was brought out of the head coil into a sitting position and then repositioned in the coil. The inversion recovery prepared 3D SPGR sequence was then repeated. A commercially available software program operating on a clinical workstation was used to automatically register the second inversion recovery prepared SPGR series to the first. The speed of registration was recorded. The accuracy of each registration was estimated by recording the coordinates of eight anatomic landmarks on the registered and reference series and by calculating the mean error among matching landmarks.

RESULTS

In nine of 10 patients, the registration software produced a visually satisfactory registration. In one patient, a second registration was necessary to produce a satisfactory registration. The processing time for each iteration was 48.3 +/- 3.8 sec (mean +/- SD). The mean error in aligning matching anatomic landmarks ranged from 0.67 to 1.41 mm, with an overall mean of 1.18 mm. The largest error among matching landmarks was 2.3 mm.

CONCLUSION

Commercially available registration software can automatically register 3D imaging volumes in less than 1 min. The mean error in registration was approximately equivalent to the dimensions of a single voxel.

Could stress cause psychosis in individuals vulnerable to schizophrenia?

It has long been considered that psychosocial stress plays a role in the expression of symptoms in schizophrenia (SZ), as it interacts with latent neural vulnerability that stems from genetic liability and early environmental insult. Advances in the understanding of the neurobiology of the stress cascade in both animal and human studies lead to a plausible model by which this interaction may occur: through neurotoxic effects on the hippocampus that may involve synaptic remodeling. Of late, the neurodevelopmental model of SZ etiology has been favored. But an elaboration of this schema that credits the impact of postnatal events and considers a role for neurodegenerative changes may be more plausible, given the evidence for gene-environment interaction in SZ expression and progressive structural changes observed with magnetic resonance imaging. Furthermore, new insights into nongliotic neurotoxic effects such as apoptosis, failure of neurogenesis, and changes in circuitry lead to an expansion of the time frame in which environmental effects may mediate expression of SZ symptoms.

Automatic volumetric measurement of lateral ventricles on magnetic resonance images with correction of partial volume effects

PURPOSE

To propose a method for the quantification of lateral ventricle (LV) volumes on a single sequence of 3D magnetic resonance (MR) images.

MATERIALS AND METHODS

This algorithm, following a preliminary fuzzy tissue classification step, is based on the development of mathematical morphology processes allowing both the extraction of the LVs and the correction of partial volume effects on their boundaries. The procedure is fast and totally unsupervised. The method is tested on a phantom image, then applied to five patients diagnosed as potentially suffering from Alzheimer's disease, and finally applied on several MR acquisitions to show the genericness of the algorithm.

RESULTS AND CONCLUSION

This technique yielded both an accurate estimation of ventricular volumes intra- and intersubject with respect to published data and a relevant management of partial volume effects. Numerous clinical applications are now expected, from the study of schizophrenia to the longitudinal follow-up of Alzheimer's patients.