Longitudinal trajectory of clinical insight and covariation with cortical thickness in first-episode psychosis

Among people with a first-episode of psychosis, those with poorer clinical insight show neuroanatomical abnormalities in frontal, temporal and parietal cortices compared to those with better clinical insight. Whether changes in clinical insight are associated with progressive structural brain changes is unknown. We aimed to evaluate 1) associations between clinical insight and cortical thickness at a baseline assessment, 2) covariation between clinical insight and cortical thickness across baseline, one-year and two-year follow-up assessments, and 3) the predictive value of clinical insight for cortical thickness at one-year and two-year follow-ups. Scale for the assessment of Unawareness of Mental Disorder ratings and magnetic resonance imaging scans were acquired at baseline, one-year, and two-year follow-ups in 128, 74, and 44 individuals with a first-episode psychosis, respectively. Cortical thickness metrics were then computed at baseline, one-year and two-year follow-ups and analyzed with linear mixed models. At baseline, clinical insight was not significantly associated with cortical thickness in any region. Longitudinal mixed effects models showed that a worsening in clinical insight between the one-year and two-year assessments was significantly associated with cortical thinning in dorsal pre-central and post-central gyri. Cortical thinning in left fusiform gyrus at two-years was predicted by poorer clinical insight at baseline. Results suggest that poor clinical insight soon after the onset of a first-episode psychosis may lead to progressive cortical changes in temporal lobe, while changes in clinical insight during the second year covary with cortical thinning in circumscribed dorsal frontal and parietal cortices.     

Neurological basis of poor insight in psychosis: a voxel-based MRI study

BACKGROUND: As a reflection of poor insight, people with schizophrenia often disagree with carers and clinicians about whether (a) their experiences are abnormal, (b) they are mentally ill, and (c) they need treatment. METHODS: This study used voxel-based morphometry to identify the associations between total and regional grey matter volumes and self-reported and observer-rated insight in 52 patients with schizophrenia or schizoaffective disorder. Thirty healthy participants were also studied. RESULTS: There were positive associations in patients between (i) the ability to recognise experiences as abnormal and the total and right superior temporal gyrus grey matter volumes, (ii), awareness of problems ('something wrong') and the left precuneus grey matter volume and (iii) awareness of symptoms and attributing them to illness and grey matter volumes in the left superior-middle temporal gyrus and the right inferior temporal and lateral parietal gyri. The 'recognition of the need for medication' dimension did not correlate with total or any regional grey matter volumes. Relative to controls, patients had less total and regional grey matter volumes in the thalamus and middle occipital and superior temporal gyri. CONCLUSIONS: Lower grey matter volumes in the temporal and parietal regions that have been implicated in self-monitoring, working memory and access to internal mental states are associated with poor insight on certain dimensions in psychosis.     

Gray matter abnormalities in paranoid schizophrenia and their clinical correlations

Numerous imaging studies have shown structural brain abnormalities in schizophrenia. Recently, voxel-based morphometry enabled whole brain analysis beyond the regions of interest (ROI). Regional gray matter concentrations of magnetic resonance (MR) images from 35 patients with paranoid schizophrenia were compared with those from 35 age- and sex-matched controls, and their clinical correlations were explored using voxel-based morphometry. Gray matter concentrations in the patients were significantly reduced in the left insular and dorsolateral prefrontal regions, and bilaterally in the medial frontal, anterior cingulate, inferior frontal and superior temporal regions. On the other hand, gray matter concentrations in the bilateral cerebellum and right striatum were significantly increased in the patients compared with controls. A negative correlation between the score for the severity of 'lack of insight and judgment' and gray matter concentrations in the left posterior and right anterior cingulate and bilateral inferior temporal regions including the lateral fusiform gyri was found. These results suggest the important roles of the paralimbic structures in the pathophysiology of schizophrenia and the involvement of the perceptual and monitoring systems in the mechanism of insight.     

Cortical thickness in frontotemporal dementia, mild cognitive impairment, and Alzheimer's disease

Cortical thickness analysis has been proposed as a potential diagnostic measure in memory disorders. In this retrospective study, we compared the cortical thickness values of 24 patients with frontotemporal dementia (FTD) to those of 25 healthy controls, 45 symptomatic subjects with stable mild cognitive impairment (S-MCI), 15 subjects with progressive mild cognitive impairment (P-MCI), and 36 patients with Alzheimer's disease (AD). The patterns of regions of thinning in FTD when compared to controls and also S-MCI patients showed similar trends; thinning of the bilateral frontal poles and bilateral medial temporal lobe structures, especially the anterior part of the gingulum, the uncus, and parahippocampal gyri. Cortical thinning in FTD was also found on the boundary regions of parietal and occipital lobes. In the P-MCI group compared to FTD, the trend of thinning in small distinct areas of the parietal and occipital lobes was observed. The FTD and AD groups did not differ statistically, but we found trends toward thinning in FTD of the left cingulate gyrus, and the left occipitotemporal gyri, and in AD of the inferior parietal, occipitoparietal, and the pericalcarine regions, more in the right hemisphere. In FTD, increased slowness in the executive test (Trail-Making A) correlated with the thinner cortex, whereas the language tests showed the lower scores, the thinner cortex in the left hemisphere. Cortical thickness might be a tool for detecting subtle changes in brain atrophy in screening of dementia prior to the development of diffuse or lobar atrophies.     

Risperidone in first-episode psychosis: a longitudinal, exploratory voxel-based morphometric study

Previous studies have provided evidence supporting a neuroplastic effect of atypical antipsychotics. The present investigation explores the short-term effects of risperidone on brain parenchyma by performing voxel-based morphometry on baseline and 6-week follow-up MRI scans obtained from 15 neuroleptic-na?ve individuals with first-episode psychosis treated with risperidone and 15 healthy controls. The risperidone-treated subjects demonstrated changes in grey matter and white matter in several brain regions, including superior temporal gyrus. No areas of change were found in controls. The results of this exploratory investigation support the possibility that risperidone has short-term effects on brain parenchyma in individuals with first-episode psychosis.     

Association of grey matter volume deviation with insight impairment in first-episode affective and non-affective psychosis

The neurobiological correlates of impaired insight in psychotic illness remain uncertain and may be confounded by factors such as illness progression and medication use. Our study consisted of two separate experiments. In the first experiment, we examined the association between measures of insight and regional brain volume in thirty-two patients with first-episode psychosis. In the second experiment, we looked at similar associations in thirty individuals with chronic schizophrenia. Detailed measures of symptom awareness and symptom attribution were obtained using the Scale to assess Unawareness of Mental Disorder. MRI scans were acquired and analysed using Statistical Non-Parametric Mapping for voxel-based analyses of grey matter maps. Regression models were used to assess the relationship between insight and grey matter volume in both the first-episode psychosis and the chronic schizophrenia experiments whilst controlling for potential confounds. In first-episode psychosis patients, symptom misattribution was associated with increased grey matter in the right and left caudate, right thalamus, left insula, putamen and cerebellum. In the chronic schizophrenia study, there were no significant associations between regional grey matter volume and measures of insight. These findings suggest that neuroplastic changes within subcortical and frontotemporal regions are associated with impaired insight in individuals during their first episode of psychosis.     

Regional increases of cortical thickness in untreated,first-episode major depressive disorder

The large majority of structural MRI studies of major depressive disorder (MDD) investigated volumetric changes in chronic medicated patients in whom course of illness and treatment effects may impact anatomic measurements. Further, in few studies, separate measurements of cortical thickness and surface area have been performed that reflect different neurobiological processes regulated by different genetic mechanisms. In the present study, we investigated both cortical thickness and surface area in first-episode, treatment-naïve, mid-life MDD to elucidate the core pathophysiology of this disease and its early impact on the brain. We observed increased cortical thickness in the right hemisphere, including medial orbitofrontal gyrus, pars opercularis, rostral middle frontal gyrus and supramarginal gyrus. Increased thickness of rostral middle frontal gyrus was negatively related with depression severity on the Hamilton Depression Rating Scale. Furthermore, MDD patients showed significantly increased associations in cortical thickness measurements among areas where increased cortical thickness was observed. Analysis of pial area revealed a trend toward increased surface area in the left parahippocampal gyrus in MDD. To permit comparison of our data with those of previous gray matter volume studies, voxel-based morphometry was performed. That analysis revealed significantly increased gray matter volume in left paracentral lobule, left superior frontal gyrus, bilateral cuneus and thalamus which form limbic-cortico–striato–pallido–thalamic loops. These changes in first-episode, treatment-naïve, mid-life MDD patients may reflect an active illness-related cortical change close to illness onset, and thus potentially provide important new insight into the early neurobiology of the disorder.     

Antipsychotics Effects on Network-Level Reconfiguration of Cortical Morphometry in First-Episode Schizophrenia

Cortical thickness reductions are evident in schizophrenia (SZ). Associations between antipsychotic medications (APMs) and cortical morphometry have been explored in SZ patients. This raises the question of whether the reconfiguration of morphological architecture by APM plays potential compensatory roles for abnormalities in the cerebral cortex. Structural magnetic resonance imaging was obtained from 127 medication-naive first-episode SZ patients and 133 matched healthy controls. Patients received 12 weeks of APM and were categorized as responders (n = 75) or nonresponders (NRs, n = 52) at follow-up. Using surface-based morphometry and structural covariance (SC) analysis, this study investigated the short-term effects of antipsychotics on cortical thickness and cortico-cortical covariance. Global efficiency was computed to characterize network integration of the large-scale structural connectome. The relationship between covariance and cortical thinning was examined by SC analysis among the top-n regions with thickness reduction. Widespread cortical thickness reductions were observed in pre-APM patients. Post-APM patients showed more reductions in cortical thickness, even in the frontotemporal regions without baseline reductions. Covariance analysis revealed strong cortico-cortical covariance and higher network integration in responders than in NRs. For the NRs, some of the prefrontal and temporal nodes were not covariant between the top-n regions with cortical thickness reduction. Antipsychotic effects are not restricted to a single brain region but rather exhibit a network-level covariance pattern. Neuroimaging connectomics highlights the positive effects of antipsychotics on the reconfiguration of brain architecture, suggesting that abnormalities in regional morphology may be compensated by increasing interregional covariance when symptoms are controlled by antipsychotics.     

Longitudinal changes in cortical thickness in children after traumatic brain injury and their relation to behavioral regulation and emotional control

The purpose of this study was to assess patterns of cortical development over time in children who had sustained traumatic brain injury (TBI) as compared to children with orthopedic injury (OI), and to examine how these patterns related to emotional control and behavioral dysregulation, two common post-TBI symptoms. Cortical thickness was measured at approximately 3 and 18 months post-injury in 20 children aged 8.2-17.5 years who had sustained moderate-to-severe closed head injury and 21 children aged 7.4-16.7 years who had sustained OI. At approximately 3 months post-injury, the TBI group evidenced decreased cortical thickness bilaterally in aspects of the superior frontal, dorsolateral frontal, orbital frontal, and anterior cingulate regions compared to the control cohort, areas of anticipated vulnerability to TBI-induced change. At 18 months post-injury, some of the regions previously evident at 3 months post-injury remained significantly decreased in the TBI group, including bilateral frontal, fusiform, and lingual regions. Additional regions of significant cortical thinning emerged at this time interval (bilateral frontal regions and fusiform gyrus and left parietal regions). However, differences in other regions appeared attenuated (no longer areas of significant cortical thinning) by 18 months post-injury including large bilateral regions of the medial aspects of the frontal lobes and anterior cingulate. Cortical thinning within the OI group was evident over time in dorsolateral frontal and temporal regions bilaterally and aspects of the left medial frontal and precuneus, and right inferior parietal regions. Longitudinal analyses within the TBI group revealed decreases in cortical thickness over time in numerous aspects throughout the right and left cortical surface, but with notable "sparing" of the right and left frontal and temporal poles, the medial aspects of both the frontal lobes, the left fusiform gyrus, and the cingulate bilaterally. An analysis of longitudinal changes in cortical thickness over time (18 months-3 months) in the TBI versus OI group demonstrated regions of relative cortical thinning in the TBI group in bilateral superior parietal and right paracentral regions, but relative cortical thickness increases in aspects of the medial orbital frontal lobes and bilateral cingulate and in the right lateral orbital frontal lobe. Finally, findings from analyses correlating the longitudinal cortical thickness changes in TBI with symptom report on the Emotional Control subscale of the Behavior Rating Inventory of Executive Function (BRIEF) demonstrated a region of significant correlation in the right medial frontal and right anterior cingulate gyrus. A region of significant correlation between the longitudinal cortical thickness changes in the TBI group and symptom report on the Behavioral Regulation Index was also seen in the medial aspect of the left frontal lobe. Longitudinal analyses of cortical thickness highlight an important deviation from the expected pattern of developmental change in children and adolescents with TBI, particularly in the medial frontal lobes, where typical patterns of thinning fail to occur over time. Regions which fail to undergo expected cortical thinning in the medial aspects of the frontal lobes correlate with difficulties in emotional control and behavioral regulation, common problems for youth with TBI. Examination of post-TBI brain development in children may be critical to identification of children that may be at risk for persistent problems with executive functioning deficits and the development of interventions to address these issues.     

Regional cerebral cortical thinning in bipolar disorder

OBJECTIVE: This study was conducted to explore differences in cortical thickness between subjects with bipolar disorder and healthy comparison subjects using cortical surface-based analysis. METHODS: Brain magnetic resonance images were acquired from 25 subjects with bipolar disorder and 21 healthy comparison subjects. Cortical surface-based analysis was conducted using the Freesurfer application. Group differences in cortical thickness, defined by the distance from gray/white boundary to the pial surface, were assessed using statistical difference maps. RESULTS: Subjects with bipolar disorder exhibited significantly decreased cortical thickness in left cingulate cortex, left middle frontal cortex, left middle occipital cortex, right medial frontal cortex, right angular cortex, right fusiform cortex and bilateral postcentral cortices, relative to healthy comparison subjects (all p < 0.001). Duration of illness in bipolar subjects was inversely correlated with the cortical thickness of the left middle frontal cortex. CONCLUSIONS: Cortical thinning was present in multiple prefrontal cortices in bipolar disorder. There was also cortical thinning in sensory and sensory association cortices, which has not been reported in previous studies using region-of-interest or voxel-based morphometry methods. Cortical thinning observed in the current study may be related to impairment of emotional, cognitive, and sensory processing in bipolar disorder but longitudinal studies will be necessary to test this hypothesis.     

Optimized voxel-based morphometry of gray matter volume in first-episode, antipsychotic-naive schizophrenia

This study examined gray matter (GM) volume abnormalities in first-episode, antipsychotic-na?ve Indian schizophrenia patients. Magnetic resonance images of 18 schizophrenia patients and 18 matched healthy comparison subjects were analyzed by optimized voxel-based morphometry. Schizophrenia patients had significantly smaller global GM and greater global CSF volumes and smaller regional GM volume in superior frontal, inferior frontal, cingulate, post-central, superior temporal and parahippocampal gyri, inferior parietal lobule, insula, caudate nuclei, thalamus and cerebellum. Findings suggest limbic, heteromodal cortical, striatal, thalamic and cerebellar abnormalities in schizophrenia.     

Widespread cortical thinning in children with frontal lobe epilepsy

Purpose: Spread of seizure activity outside the frontal lobe due to cortico‐cortical connections can result in alteration in the cortex beyond the frontal lobe in children with intractable frontal lobe epilepsy (FLE). The aim of this study was to identify regions of reduced cortical thickness in children with intractable FLE. Methods: High‐resolution volumetric T₁‐weighted imaging was performed on 17 children with FLE, who were being evaluated for epilepsy surgery, and 26 age‐matched healthy controls. The cortical thickness of 12 patients with left FLE and 5 patients with right FLE was compared to controls. The clusters of cortical thinning were regressed against age of seizure onset, duration of epilepsy, seizure frequency, and number of medications. Key Findings: In children with left FLE, cortical thinning was present in the left superior frontal, paracentral, precuneus, cingulate, inferior parietal, supramarginal, postcentral, and superior temporal gyri, as well as in the right superior and middle frontal, medial orbitofrontal, supramarginal, postcentral, banks of superior temporal sulcus, and parahippocampal gyri. In children with right FLE, cortical thinning was present in the right precentral, postcentral, transverse temporal, parahippocampal, lingual, and lateral occipital gyri, as well as in the left superior frontal, inferior parietal, postcentral, superior temporal, posterior cingulate, and lingual gyri. In children with left FLE, following exclusion of one outlier, there was no significant association between age at seizure onset, duration of epilepsy, seizure frequency and number of medications with clusters of cortical thinning. In children with right FLE, age at seizure onset, duration of epilepsy, frequency of seizures, and number of medications were not associated with clusters of cortical thinning within the right and left hemispheres. Significance: Cortical changes were present in the frontal and extrafrontal cortex in children with intractable FLE. These changes may be related to spread of seizure activity, large epileptogenic zones involving both frontal and extrafrontal lobes, and development of secondary epileptogenic zones that over time lead to cortical abnormality. Further studies correlating cortical changes with neurocognitive measures are needed to determine if the cortical changes relate to cognitive function.     

Structural brain abnormalities in early onset first-episode psychosis

Summary Background. Brain morphometry in children and adolescents with first-episode psychosis offer a unique opportunity for pathogenetic investigations. Methods. We compared high-resolution 3D T1-weighted magnetic resonance images of the brain in 29 patients (schizophrenia, schizotypal disorder, delusional disorder or other non-organic psychosis), aged 10–18 to those of 29 matched controls, using optimized voxel-based morphometry. Results. Psychotic patients had frontal white matter abnormalities, but expected (regional) gray matter reductions were not observed. Post hoc analyses revealed that schizophrenia patients (n = 15) had significantly larger lateral ventricles as compared to controls. Duration and dose of antipsychotics correlated negatively with global gray matter volume in minimally medicated patients (n = 18). Conclusion. Findings of white matter changes and enlarged lateral ventricles already at illness onset in young schizophrenia spectrum patients, suggests aberrant neurodevelopmental processes in the pathogenesis of these disorders. Gray matter volume changes, however, appear not to be a key feature in early onset first-episode psychosis.     

Gray matter volume differences and the effects of smoking on gray matter in schizophrenia

OBJECTIVE: Many studies have evaluated differences in gray matter volume in schizophrenia, but have not considered the possible effects of smoking, which is extraordinarily common in people with the illness. The present study used voxel-based morphometry (VBM) to examine differences in gray matter in subjects with schizophrenia and evaluate the effects of smoking on this measure. METHODS: Thirty-two subjects with schizophrenia (14 smokers, 18 non-smokers) and 32 healthy comparison subjects participated in the study. Whole brain, voxel-wise analyses of regional gray matter volume were conducted using voxel-based morphometry (VBM). RESULTS: Reduced gray matter was observed in the schizophrenia group in the orbitofrontal cortex, bilateral insula and superior temporal gyri (STG), bilateral dorsolateral prefrontal cortices (DLPFC), medial frontal gyrus, and cingulate gyrus. Within this group, smoking subjects had greater lateral prefrontal and STG gray matter volumes relative to non-smoking subjects. CONCLUSIONS: The finding of reduced gray matter volume in prefrontal and temporal regions in schizophrenia is consistent with prior anatomical tracing and whole-brain voxel-based studies. Greater gray matter volumes in smoking relative to non-smoking subjects with schizophrenia highlight a potential experimental confound in volumetric studies and suggests that smoking may be associated with a relative preservation of lateral prefrontal and temporal gray matter in schizophrenia.     

Age-Related Reduction in Cortical Thickness in First-Episode Treatment-Na?ve Patients with Schizophrenia

Substantial evidence supports the neurodevelopmental hypothesis of schizophrenia.Meanwhile,progressive neurodegenerative processes have also been reported,leading to the hypothesis that neurodegeneration is a characteristic component in the neuropathology of schizophrenia.However,a major challenge for the neurodegenerative hypothesis is that antipsychotic drugs used by patients have profound impact on brain structures.To clarify this potential confounding factor,we measured the cortical thickness across the whole brain using highresolution T1-weighted magnetic resonance imaging in 145 first-episode and treatment-naive patients with schizophrenia and 147 healthy controls.The results showed that,in the patient group,the frontal,temporal,parietal,and cingulate gyri displayed a significant age-related reduction of cortical thickness.In the control group,age-related cortical thickness reduction was mostly located in the frontal,temporal,and cingulate gyri,albeit to a lesser extent.Importantly,relative to healthy controls,patients exhibited a significantly smaller age-related cortical thickness in the anterior cingulate,inferior temporal,and insular gyri in the right hemisphere.These results provide evidence supporting the existence of neurodegenerative processes in schizophrenia and suggest that these processes already occur in the early stage of the illness.     

Neuroanatomical Maps of Psychosis Onset: Voxel-wise Meta-Analysis of Antipsychotic-Naive VBM Studies

Background: Despite impressive advancements in early interventions in psychosis, there is an urgent need of robust neurobiological markers to improve the predictive value of psychosis transition. Available structural imaging literature in the field is undermined by several methodological caveats and a number of confounders such as exposure to antipsychotic treatment. Methods: Fourteen voxel-based morphometry studies of antipsychotic-naive subjects at enhanced clinical risk for psychosis (high risk [HR]) or experiencing a first-episode psychosis (FEP) were included. Formal meta-analysis of effect sizes and “signed differential mapping” voxel-based meta-analysis were combined to control the results for sample sizes, strength of individual findings, and confounding variables. Results: Formal effect size meta-analysis indicated consistent gray matter (GM) reductions both in subjects at enhanced clinical risk for psychosis and in first-episode subjects when compared with control groups. Voxel-based meta-analysis showed GM reductions in the temporal, limbic prefrontal cortex within the HR group and in the temporal insular cortex and cerebellum within the FEP group. Psychosis onset was characterized by GM decreases in temporal, anterior cingulate, cerebellar, and insular regions. GM alterations in the temporal regions directly related to severity of psychotic symptoms. There was no publication bias. Heterogeneity across studies was low. Sensitivity analyses confirmed robustness of the above results. Conclusions: Vulnerability to psychosis is associated with consistent GM decreases in prefrontal and temporolimbic areas. The onset of full disease is accompanied by temporoinsular, anterior cingulate, and cerebellar GM reductions. Neuroanatomical alterations in temporal regions may underlie the clinical onset of psychotic symptoms.     

Temporal Lobe Volume Abnormalities Precede the Prodrome: A Study of Children Presenting Antecedents of Schizophrenia

Distributed abnormalities of gray matter (GM) and white matter (WM) volume characterize individuals experiencing their first episode of schizophrenia. Regions of abnormality are present already, albeit less extensively, during the prodromal phase of illness. This study aimed to determine whether putatively at-risk children, aged 9–12 years, who present multiple antecedents of schizophrenia (ASz), display GM and WM volume abnormalities relative to typically developing (TD) children presenting no antecedents. Structural magnetic resonance images were acquired for 20 ASz children and 20 TD children matched on age, sex, and IQ. Whole-brain differences in GM and WM volume were determined using voxel-based morphometry. Relative to the TD group, ASz children showed significantly decreased GM volume in the right middle temporal gyrus (MTG) and increased GM volume in the left superior-middle temporal gyri (P < 0.05, cluster correction). WM volume was significantly increased in ASz children relative to TD children in a cluster encompassing the left inferior parietal lobe, occipital lobe, and superior temporal gyrus. Post-hoc analyses indicated that these abnormalities were not limited to ASz children who self-reported auditory hallucinations on questionnaire. Our findings suggest that children aged 9–12 years who present multiple ASz are characterized by abnormalities of GM and WM volume in the temporal lobes, comprising a subset of the regions affected in first-episode schizophrenia and in the prodromal phase of illness. These preliminary findings indicate that structural brain abnormalities associated with schizophrenia may be detected in putatively at-risk, preprodromal children. Prospective studies following the brain development of at-risk children are needed.Key words: psychosis, high risk, MRI, VBM, biomarkers, brain structure     

Assessment of cortical degeneration in patients with Parkinson's disease by voxel-based morphometry, cortical folding, and cortical thickness

Noninvasive brain imaging methods provide useful information on cerebral involution and degenerative processes. Here we assessed cortical degeneration in 20 nondemented patients with Parkinson's disease (PD) and 20 healthy controls using three quantitative neuroanatomical approaches: voxel‐based morphometry (VBM), cortical folding (BrainVisa), and cortical thickness (FreeSurfer). We examined the relationship between global and regional gray matter (GM) volumes, sulcal indices, and thickness measures derived from the previous methods as well as their association with cognitive performance, age, severity of motor symptoms, and disease stage. VBM analyses showed GM volume reductions in the left temporal gyrus in patients compared with controls. Cortical folding measures revealed significant decreases in the left frontal and right collateral sulci in patients. Finally, analysis of cortical thickness showed widespread cortical thinning in right lateral occipital, parietal and left temporal, frontal, and premotor regions. We found that, in patients, all global anatomical measures correlated with age, while GM volume and cortical thickness significantly correlated with disease stage. In controls, a significant association was found between global GM volume and cortical folding with age. Overall these results suggest that the three different methods provide complementary and related information on neurodegenerative changes occurring in PD, however, surface‐based measures of cortical folding and especially cortical thickness seem to be more sensitive than VBM to identify regional GM changes associated to PD. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.     

Middle and inferior temporal gyrus gray matter volume abnormalities in first-episode schizophrenia: an MRI study

OBJECTIVE: Magnetic resonance imaging (MRI) studies of schizophrenia reveal temporal lobe structural brain abnormalities in the superior temporal gyrus and the amygdala-hippocampal complex. However, the middle and inferior temporal gyri have received little investigation, especially in first-episode schizophrenia. METHOD: High-spatial-resolution MRI was used to measure gray matter volume in the inferior, middle, and superior temporal gyri in 20 patients with first-episode schizophrenia, 20 patients with first-episode affective psychosis, and 23 healthy comparison subjects. RESULTS: Gray matter volume in the middle temporal gyrus was smaller bilaterally in patients with first-episode schizophrenia than in comparison subjects and in patients with first-episode affective psychosis. Posterior gray matter volume in the inferior temporal gyrus was smaller bilaterally in both patient groups than in comparison subjects. Among the superior, middle, and inferior temporal gyri, the left posterior superior temporal gyrus gray matter in the schizophrenia group had the smallest volume, the greatest percentage difference, and the largest effect size in comparisons with healthy comparison subjects and with affective psychosis patients. CONCLUSIONS: Smaller gray matter volumes in the left and right middle temporal gyri and left posterior superior temporal gyrus were present in schizophrenia but not in affective psychosis at first hospitalization. In contrast, smaller bilateral posterior inferior temporal gyrus gray matter volume is present in both schizophrenia and affective psychosis at first hospitalization. These findings suggest that smaller gray matter volumes in the dorsal temporal lobe (superior and middle temporal gyri) may be specific to schizophrenia, whereas smaller posterior inferior temporal gyrus gray matter volumes may be related to pathology common to both schizophrenia and affective psychosis.     

Mapping the neuroanatomical impact of very preterm birth across childhood

Those born very preterm (VPT; <32 weeks gestational age) have an increased risk in developing a wide range of cognitive deficits. In early‐to‐late childhood, brain structure has been shown to be altered in VPT compared to full‐term (FT) children; however, the results are inconsistent. The current study examined subcortical volumes, cortical thickness, and surface area in a large cohort of VPT and FT children aged 4–12 years. Structural magnetic resonance imaging (MRI) was obtained on 120 VPT and 146 FT children who returned up to three times, resulting in 176 VPT and 173 FT unique data points. For each participant, Corticometric Iterative Vertex‐based Estimation of Thickness was used to obtain global measurements of total brain, cortical grey and cortical white matter volumes, along with surface‐based measurements of cortical thickness and surface area, and Multiple Automatically Generated Templates (MAGeT) brain segmentation tool was used to segment the subcortical structures. To examine group differences and group–age interactions, mixed‐effects models were used (controlling for whole‐brain volume). We found few differences between the two groups in subcortical volumes. The VPT children showed increased cortical thickness in frontal, occipital and fusiform gyri and inferior pre–post–central areas, while thinning occurred in the midcingulate. Cortical thickness in occipital regions showed more rapid decreases with age in the VPT compared to the FT children. VPT children also showed both regional increases, particularly in the temporal lobe, and decreases in surface area. Our results indicate a delayed maturational trajectory in those born VPT.