Surface-based Morphometry Study Research Articles

Grey matter abnormalities in major depressive disorder patients with suicide attempts: A systematic review of age-specific differences

BackgroundPrevious studies have reported alterations in brain structure in major depressive disorder (MDD) patients with suicide attempts. However, age-related changes in suicidal MDD patients remain unclear. MethodsWe performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Embase, PubMed, and Web of Science were searched to identify relevant studies from inception to January 2023. All voxel-based and surface-based morphometry studies comparing suicidal MDD patients to MDD or healthy controls were included. Studies were then grouped by age range (old, middle-age, adolescent) and the commonalities and age-related structural brain alterations were summarized. The included studies were evaluated using the Newcastle-Ottawa Scale (NOS). ResultsA total of 17 studies met the inclusion criteria, including 3 of late-life depression (LLD) patients, 11 of middle-aged depression (MAD) patients, and 3 of adolescent depression (AOD) patients. The majority of studies had moderate to high NOS scores, indicating good quality. Patients in all three age groups exhibited extensive alterations in the lateral, medial, and orbital regions of the frontal lobes. Furthermore, suicidal MAD patients showed a specific decrease in the gray matter volume of the dorsolateral prefrontal cortex compared to suicidal LLD patients. Cortical thickness and left angular gyrus volume were decreased in suicidal MAD and suicidal LLD patients, but increased in suicidal AOD patients. ConclusionThis systematic review summarizes structural brain changes in suicidal MDD patients at three age groups: elderly, middle-aged, and adolescent. These findings help elucidate the common circuitry of MDD related to suicide over the lifespan and highlight unique circuitry associated with different ages. These findings may help predict the risk of suicide in MDD patients at different ages.

Micro and macro changes in early stage of type 2 diabetes mellitus without cognitive impairment: A diffusion tensor imaging (DTI) and surface-based morphometry (SBM) study

Micro and macro changes in early stage of type 2 diabetes mellitus without cognitive impairment: A diffusion tensor imaging (DTI) and surface-based morphometry (SBM) study

Micro- and macro-changes in early-stage type 2 diabetes mellitus without cognitive impairment: a diffusion tensor imaging (DTI) and surface-based morphometry (SBM) study.

Brain structure and function changes are considered major brain damages in type 2 diabetes mellitus (T2DM), which likely has a close relationship with cognitive impairment. Many previous studies have shown by using brain structural and functional magnetic resonance imaging (MRI) methods that brain white and gray matter are damaged in T2DM, leading to cognitive impairment. Researches neglected patients of T2DM without cognitive dysfunction might also have brain changes. In this study, subjects with early stage T2DM with no cognitive dysfunction were enrolled to detect brain damages using the tract-based spatial statistics analysis (TBSS) method to demonstrate white matter (WM) micro changes and surface-based morphometry (SBM) method to assess cerebral cortex macro changes. The whole-brain TBSS analysis revealed that there were no statistically significant changes in fractional anisotropy (FA) and mean diffusivity (MD), but the FA declined in some area of cerebral WM (p < 0.1). The SBM results showed no changes in cortical thickness (CT), cortical volume (CV), surface area (SA), and cortical sulcal curve (CSC) between these two groups, but pial local gyration index (LGI) was decreased in the precuneus (-log10, p = -3.327). In conclusion, early stage T2DM patients without cognitive impairment had brain micro and macro structural damages, suggesting the potential use of MRI as an imaging marker to detect brain changes in early stage T2DM, which could not be observed and assessed clinically.

Surface-based morphometry study of brain in patients with carbon monoxide poisoning

PurposeAlthough cortical volume abnormalities are frequently detected in patients with carbon monoxide poisoning (COP), particularly delayed neurological sequelae (DNS), the associated changes in cortical thickness and shape patterns remain unknown. Materials & MethodsUsing surface-based morphometry, we investigated the differences in cortical thickness and shape indices between a COP group (n = 44) vs healthy controls (HCs, n = 36), and between the DNS (n = 21) vs non-DNS (n = 23) subgroups. Additionally, the influence of cortical damage on neurological disorders was explored. ResultsThe COP group exhibited significant cortical thinning mainly in the bilateral fronto-parietal lobes (P < 0.05, family-wise error corrected). When cortical thinning in the bilateral parietal lobes, bilateral primary motor areas, left primary sensory areas, and bilateral paracentral lobules was explored in the DNS subgroups compared to the non-DNS subgroup (P < 0.05, FWE corrected), no differences in shape indices between the two subgroups were noted. In the COP group, there were significant positive correlations between the Mini-Mental State Examination (MMSE) score and cortical thickness in the right superior frontal gyrus (SFG) and bilateral rostral middle frontal gyrus (rMFG) (P < 0.05, false discovery rate corrected). There was no any significant correlation between cortical thickness and Neuropsychiatric inventory (NPI), UPDRS III scores (P > 0.05, FDR-corrected). ConclusionCortical thickness is a more sensitive index than shape for measuring cortical damage in patients with COP exposure, as cortical thinning in the right SFG and bilateral rMFG is related to cognitive impairment.

Coordinate-Based Network Mapping of Brain Structure in Major Depressive Disorder in Younger and Older Adults: A Systematic Review and Meta-Analysis.

Structural neuroimaging findings in younger and older adults with major depressive disorder (MDD) are highly heterogeneous, possibly as a result of methodological limitations, lack of distinction between MDD and late-life depression (LLD), or clinical moderators. Using a novel meta-analytic network mapping approach, the authors sought to identify the circuits affected in different clinical subtypes of MDD. The authors identified all voxel-based and surface-based morphometry studies published through October 2020 that compared younger adults with MDD or older adults with LLD to nonpsychiatric control participants. An activation likelihood estimation (ALE) analysis and a novel coordinate-based network mapping approach were used to identify brain circuits affected in MDD and LLD. Meta-regressions examined the impact of age at onset in older patients with LLD and treatment with antidepressants in younger patients with MDD. The authors analyzed 145 comparisons from 143 articles, including a total of 14,318 participants (MDD: N=6,362; LLD: N=535; control subjects: N=7,421). Significant ALE results confirmed previous findings implicating the left and right parahippocampus and anterior cingulate in MDD and the anterior cingulate in LLD. In contrast, coordinate-based network mapping showed differences in the frontoparietal, dorsal attention, and visual networks both in MDD and LLD. Meta-regressions showed that late onset was significantly associated with widespread structural abnormalities in LLD, and treatment with antidepressants showed a significant association with abnormalities in the anterior cingulate (Brodmann's area 32) and dorsolateral prefrontal cortex (Brodmann's area 9) in MDD. These findings help to clarify the shared circuitry of depression across the adult lifespan and highlight some unique circuitry relevant to late-onset depression, which may explain some of the risk for cognitive decline and dementia.

Whole brain surface-based morphometry study in subtypes of migraine with aura patients

Little is known about the pathophysiologic basis of the clinical variability of migraine aura presentation. We were aimed to study intracerebral white matter fiber bundles, using a tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI), and grey matter cortical thickness from structural magnetic resonance imaging data in migraine patients with pure visual auras (MA), and in patients with complex neurological auras (MA+), i.e. with the addition of at least one of sensory and language symptoms.

Abnormalities of cortical structures in patients with postpartum depression: A surface-based morphometry study

BackgroundPostpartum depression (PPD) is a serious postpartum mental health problem worldwide. However, the cortical structural alterations in patients with PPD remain unclear. This study investigated the cortical structural alterations of PPD patients through multidimensional structural patterns and their potential correlations with clinical severity. MethodsHigh-resolution 3D T1 structural images were acquired from 21 drug-naive patients with PPD and 18 healthy postpartum women matched for age, educational level, and body mass index. The severity of PPD was assessed by using the Hamilton Depression Scale (HAMD) and Edinburgh Postnatal Depression Scale (EPDS) scores. Cortical morphological parameters including cortical thickness, surface area, and mean curvature were calculated using the surface-based morphometric (SBM) method. General linear model (GLM) analyses were performed to evaluate the relationship of cortical morphological parameters with clinical scales. ResultsIn the present study, PPD patients showed a thinner cortical thickness in the right inferior parietal lobule compared with the healthy controls. Increased surface area was observed in the left superior frontal gyrus, caudal middle frontal gyrus, middle temporal gyrus, insula, and right supramarginal cortex in PPD patients. Likewise, PPD patients exhibited a higher mean curvature in the left superior and right inferior parietal lobule. Furthermore, increased cortical surface area in the left insula had a positive correlation with EPDS scores, and higher mean curvature in the left superior parietal lobule was negatively correlated with EPDS scores. LimitationsFirst, SBM cannot reflect the changes of subcortical structures that are considered to play a role in the development of PPD. Second, the sample size of this study is small. These positive results should be interpreted with caution. Third, this cross-sectional study does not involve a comparison of structural MRI before and after pregnancy. ConclusionsThe complex cortical structural alterations of patients with PPD mainly involved the prefrontal and parietal regions. The morphometric alterations in these specific regions may provide promising markers for assessing the severity of PPD.

Multimodal magnetic resonance spectroscopy and surface-based morphometry study of individuals at ultra-high-risk for psychosis

IntroductionStudies examining gamma-aminobutyric acid (GABA) or glutamate in ultra-high risk for psychosis (UHR) have shown conflicting results, and a number of multimodal studies examining associations between metabolite and structural characteristics is very limited.ObjectivesWe aimed to investigate potential associations between GABA and glutamate levels and cortical thickness in the frontal lobe in UHR individuals and healthy controls (HC).Methods20 male UHR individuals and 19 healthy controls (HC) underwent structural MRI and MR spectroscopy at 3T Philips scanner. T1-weighted images were processed via FreeSurfer 6.0 to quantify cortical thickness for selected frontal regions labeled according to Desikan atlas. MEGA-PRESS acquisitions were analyzed with jMRUi (ver. 5.1 Alpha), levels of GABA and glutamate were calculated as ratios to creatine + phosphocreatine.ResultsThe study revealed: 1) GABA/Cr ratios reduction in the left frontal lobe (p=0.001) which was not attributable to antipsychotic medication; 2) cortical thickness reductions in the left pars orbitalis (p=0.005) (the anterior part of the inferior frontal gyrus) in the UHR individuals compared to HC. No significant correlations between GABA/Cr ratios and cortical thickness were identified in both groups.ConclusionsThe findings indicate that the UHR state is associated with altered GABA levels and cortical thickness reductions in the prefrontal cortex. The results also show that GABA levels are not directly related to cortical abnormalities, suggesting that altered metabolite levels may be associated with a complex system of structural and functional impairments, rather than directly correlating with structural changes in separate cortical regions. The work was supported by RFBR grant 19-29-10040.DisclosureNo significant relationships.

A surface-based morphometry study of risk and resilience markers associated with supramarginal thickness in schizophrenia

IntroductionConventional structural neuroimaging methods can identify changes in cortical thickness but cannot relate these changes to specific cortical layers due to a lack of sensitivity. However, several indirect measures sensitive to changes specifically occurring in supragranular cortical layers were developed recently (github.com/kwagstyl/schizophrenia_gyral_sulcal).ObjectivesThe aim was to assess the ability of these novel measures to detect cortical layers thickness characteristics potentially associated with risk or resilience to developing schizophrenia.Methods43 first-episode schizophrenia (FES) male patients, 29 non-converted individuals at ultra-high risk of psychosis (ncUHR, mean follow-up period – 6.5 years), and 43 matched healthy controls (HC) underwent structural MRI at 3T Philips scanner. Images were processed via FreeSurfer and MATLAB to derive two markers specific to supragranular thickness change: gyral-sulcal thickness differences (GSTD) and gyral-sulcal intrinsic curvature differences on pial surface (GSCD).ResultsGSCD measures were increased in temporal, parietal and occipital cortices, whereas both GSTD and GSCD were increased in the right frontal cortex in FES compared to HC. No GSTD or GSCD were changed in ncUHR compared to HC, and GSCD was decreased in the frontal cortex compared to FES.ConclusionsOur findings from the indirect measures indicate a potential predominance of supragranular thinning in FES and suggest that a supragranular thinning in the right frontal lobe might be associated with precipitating risk and/or illness effects of schizophrenia. At the same time, no clear supragranular markers directly associated with resilience or risk mechanisms were identified. The work was supported by RFBR grant 20-013-00748.

Cortical Thickness Alterations in Patients With Tinnitus Before and After Sound Therapy: A Surface-Based Morphometry Study.

This study aimed to explore brain surface-based morphometry cortical thickness changes in patients with idiopathic tinnitus before and after 24 weeks of sound therapy. In this prospective observational study, we recruited 33 tinnitus patients who had undergone 24 weeks of sound therapy and 26 matched healthy controls. For the two groups of subjects, a 3D-BRAVO pulse sequence was acquired both at baseline and at the 24th week. Structural image data preprocessing was performed using the DPABISurf toolbox. The Tinnitus Handicap Inventory (THI) score was assessed to determine the severity of tinnitus before and after treatment. Two-way mixed-model analysis of variance (ANOVA) and Pearson’s correlation analysis were used in the statistical analysis. Student–Newman–Keuls (SNK) tests were used in the post hoc analysis. Significantly lower cortical thickness was found in the left somatosensory and motor cortex (SMC), left posterior cingulate cortex (PCC), and right orbital and polar frontal cortex (OPFC) of the participants in the tinnitus group at baseline than in the participants in the HC group at baseline and after 24 weeks; in the tinnitus group, significantly higher cortical thickness was found after the 24 weeks sound therapy in comparison to the baseline in the left SMC, bilateral superior parietal cortex (SPC), left inferior parietal cortex (IPC), left PCC, and right OPFC. In the HC group, no statistically significant difference in cortical thickness was found after the 24 weeks treatment in comparison to the baseline in the bilateral SMC, bilateral SPC, left IPC, left PCC, or right OPFC. The changes in cortical thickness before and after sound therapy can provide certain reference values for clinical tinnitus treatment. These brain regions could serve as potential targets for neuroimaging.

Cortical Gyrification Morphology in Individuals with ASD and ADHD across the Lifespan: A Systematic Review and Meta-Analysis.

Autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) are common neurodevelopmental disorders (NDDs) that may impact brain maturation. A number of studies have examined cortical gyrification morphology in both NDDs. Here we review and when possible pool their results to better understand the shared and potentially disorder-specific gyrification features. We searched MEDLINE, PsycINFO, and EMBASE databases, and 24 and 10 studies met the criteria to be included in the systematic review and meta-analysis portions, respectively. Meta-analysis of local Gyrification Index (lGI) findings across ASD studies was conducted with SDM software adapted for surface-based morphometry studies. Meta-regressions were used to explore effects of age, sex, and sample size on gyrification differences. There were no significant differences in gyrification across groups. Qualitative synthesis of remaining ASD studies highlighted heterogeneity in findings. Large-scale ADHD studies reported no differences in gyrification between cases and controls suggesting that, similar to ASD, there is currently no evidence of differences in gyrification morphology compared with controls. Larger, longitudinal studies are needed to further clarify the effects of age, sex, and IQ on cortical gyrification in these NDDs.

Differences in cortical structure between cognitively normal East Asian and Caucasian older adults: a surface-based morphometry study

There is a growing literature on the impact of ethnicity on brain structure and function. Despite the regional heterogeneity in age-related changes and non-uniformity across brain morphometry measurements in the aging process, paucity of studies investigated the difference in cortical anatomy between the East Asian and Caucasian older adults. The present study aimed to compare cortical anatomy measurements, including cortical thickness, volume and surface area, between cognitively normal East Asian (n = 171) and Caucasian (n = 178) older adults, using surface-based morphometry and vertex-wise group analysis of high-dimensional structural magnetic resonance imaging (MRI) data. The East Asian group showed greater cortical thickness and larger cortical volume in the right superior temporal gyrus, postcentral gyrus, bilateral inferior temporal gyrus, and inferior parietal cortex. The Caucasian group showed thicker and larger cortex in the left transverse temporal cortex, lingual gyrus, right lateral occipital cortex, and precentral gyrus. Additionally, the difference in surface area was discordant with that in cortical thickness. Differences in brain structure between the East Asian and Caucasian might reflect differences in language and information processing, but further studies using standardized methods for assessing racial characteristics are needed. The research results represent a further step towards developing a comprehensive understanding of differences in brain structure between ethnicities of older adults, and this would enrich clinical research on aging and neurodegenerative diseases.

Surface-based morphometry study of the brain in benign childhood epilepsy with centrotemporal spikes

BackgroundThe study aimed to explore cortical morphology in benign childhood epilepsy with centrotemporal spikes (BECTS) and the relationship between cortical characteristics and age of onset and intelligence quotient (IQ).MethodsCortical morphometry with surface-based morphometry (SBM) was used to compare changes in cortical thickness, gyrification, sulcal depth, and fractal dimension of the cerebral cortex between 25 BECTS patients and 20 healthy controls (HCs) with two-sample t-tests [P<0.05, family-wise error (FWE) corrected]. Relationships between abnormal cortical morphological changes and age of onset and IQ, which included verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full-scale intelligence quotient (FIQ) were investigated with Spearman correlation analysis (P<0.05, uncorrected).ResultsThe BECTS patients showed extensive cortical thinning predominantly in bilateral frontal, temporal regions, and limbic system. Cortical gyrification increased in the left hemisphere and partial right hemisphere, and the decreased cortical gyrification was only in the left hemisphere. The increased sulcal depth was the left fusiform gyrus. There are no statistically significant differences in the fractal dimension. Correlation analysis revealed the negative correlation between age of onset and cortical thickness in the right precentral gyrus. It also revealed the negative correlation between the age of onset and cortical gyrification in the left inferior parietal gyrus. Also, there was negative correlation between VIQ and cortical gyrification in the left supramarginal gyrus of BECTS patients.ConclusionsThis study reveals aberrant cortical thickness, cortical gyrification, and sulcal depth of BECTS in areas related to cognitive functions including language, attention and memory, and the correlation between some brain regions and VIQ and age of onset, providing a potential marker of early neurodevelopmental disturbance and cognitive dysfunction in BECTS.

Comparison of first-episode and multiple-episode bipolar disorder: A surface-based morphometry study

It is still unclear whether the structural abnormalities in Bipolar disorder (BD) are static or progressive. We aimed to compare differences in cortical thickness, surface area, and volume between patients with BD and healthy volunteers (HV) and to examine whether there are differences between patients who have had a single manic episode and those with multiple episodes. We recruited 30 patients with Type I BD and 30 age and sex matched HV. All participants underwent structural magnetic resonance imaging. Cortical volume, thickness, and surface area were measured using the QDEC tool from the Freesurfer software with age and intracranial volume as covariates. Study groups were comparable across age, sex distribution, and intracranial volume. Patients had significantly lower surface area in bilateral cuneus, right postcentral gyrus, and rostral middle frontal gyri; and lower cortical volume in the left middle temporal gyrus, right postcentral gyrus, and right cuneus. BD patients with multiple episodes had lower cortical measures while those with single episode had cortical measures comparable to HV. Findings indicate that the pathophysiological processes in BD are possibly progressive in nature. Our findings underscore the potential importance of early diagnosis and intervention in preventing deterioration and improving functional recovery.

Brain Structural Plasticity Associated with Maternal Caregiving in Mothers: A Voxel- and Surface-Based Morphometry Study

Background: Pregnancy constitutes a significant period in the lives of women, after which they often experience numerous crucial physiological and psychological changes. Functional neuroimaging studies have shown longitudinal changes in functional brain activity in mothers responding to infant-related stimuli. However, the structural changes that occur in the brains of mothers after delivery remain to be explored. Objective: We aimed to evaluate the structural changes in mothers during the postpartum phase. Methods: We recruited 35 primiparous mothers and 26 nonmothers to participate in this voxel- and surface-based morphometry study, and 22 mothers were scanned twice with a follow-up of approximately 2 years. Results: Compared to nonmothers, mothers exhibited reduced gray matter (GM) volumes and increased white matter (WM) volumes in regions associated with empathy and reward networks (supplementary motor area, precuneus, inferior parietal lobe, insula, and striatum), decreased cortical thickness in the precentral gyrus and increased gyrification index in the orbitofrontal cortex. Furthermore, mothers showed longitudinal changes in the GM and WM volumes and cortical thickness of several of these regions (including the superior and medial frontal gyrus, insula, limbic lobe, superior and middle temporal gyrus, and precentral gyrus), which have been associated with maternal networks during the postpartum period. Additionally, the changes in GM and WM volumes were related to changes in empathetic abilities in mothers. Conclusion: These results suggest that the brains of mothers exhibit adaptive structural dynamic plasticity. These findings provide a neuroanatomical basis for understanding how mothers process emotional sensory information during the postpartum period.

Coordinate-Based Network Mapping of Brain Structure in Major Depressive Disorder in Younger and Older Adults: A Systematic Review and Meta-Analysis

Background: Neuroimaging findings in younger and older adults with major depressive disorder (MDD) are highly heterogeneous. It is unclear whether this heterogeneity is due to methodological limitations, lack of distinction between MDD and late-life depression (LLD), or clinical moderators. Methods: We identified all voxel-based and surface-based morphometry studies comparing younger adults with MDD or older adults with LLD to non-psychiatric control participants (updated search: Oct 27, 2020). We used both an Activation Likelihood Estimation (ALE) analysis and a novel coordinate-based network mapping to identify brain circuits affected in MDD and LLD. We then used meta-regressions to examine the impact of age of onset in older patients with LLD and treatment with antidepressants in younger patients with MDD. Results: We analysed 145 comparisons from 143 articles including 14,318 participants (MDD; 6,362; LDD: 535; controls: 7,421). Our ALE results confirmed previous findings implicating the bilateral parahippocampus (z RIGHT =5.2, z LEFT =4.3, p FWE <0.001) and anterior cingulate (z RIGHT =3.6, z LEFT =4.5 p FWE <0.005) in MDD and anterior cingulate (z RIGHT =3.7, z LEFT =3.6 p FWE <0.005) in LLD. In contrast, coordinate-based network mapping showed differences in the frontoparietal, dorsal attention, and visual networks both in MDD and LLD. Meta-regressions showed that late onset was associated with widespread structural abnormalities in LLD and treatment with antidepressants was associated with abnormalities in the anterior cingulate (BA32, t 1,116 =3.8, p FDR =0.03) and dorsolateral prefrontal cortex (BA9, t 1,116 =3.0, p FDR =0.04) in MDD. Conclusions: While ALE identified specific brain regions affected in MDD, coordinate-based network mapping was more sensitive to disruptions in both MDD and LLD. Meta-regression identified additional differences related to age of onset and treatment with antidepressants. These findings help clarify the shared circuitry of depression across the adult lifespan and highlight some unique circuitry relevant to late-onset depression, which may explain some of the risk for cognitive decline and dementia. Funding Statement: Andrea Cipriani is supported by the National Institute for Health Research (NIHR) Oxford Cognitive Health Clinical Research Facility, by an NIHR Research Professorship (grant RP- 2017-08-ST2-006), by the NIHR Oxford and Thames Valley Applied Research Collaboration and by the NIHR Oxford Health Biomedical Research Centre (grant BRC-1215-20005). Declaration of Interests: PZ was funded by the Labatt Family Postdoctoral Fellowship in Depression Biology. JAEA was funded by Canadian Institute of Health Research CIHR fellowship Grant No. CIHR-IRSC: 0093005620. B.H. Mulsant receives support from the Labatt Family Chair in Biology of Depression in Late-Life Adults at the University of Toronto; he currently receives research support from Brain Canada, the Canadian Institutes of Health Research, the CAMH Foundation, the Patient-Centered Outcomes Research Institute (PCORI), the US National Institute of Health (NIH), Capital Solution Design LLC (software used in a study founded by CAMH Foundation), and HAPPYneuron (software used in a study funded by Brain Canada). He directly owns stocks of General Electric (less than $5,000). Within the past five years, he has also received research support from Eli Lilly (medications and matching placebo pills for a NIH-funded clinical trial) and Pfizer (medications for a NIH-funded clinical trial) and he has been an unpaid consultant to Myriad Neuroscience. Andrea Cipriani has received research and consultancy fees from INCiPiT (Italian Network for Paediatric Trials), CARIPLO Foundation and Angelini Pharma. ANV currently receives funding from CIHR, the NIH, the National Sciences and Engineering Research Council (NSERC), the CAMH Foundation, and the University of Toronto.

Cerebral correlates of switching during verbal fluency task and its impairment in depression: A surface-based morphometry study

Background Major depressive disorder (MDD) is a highly disabling disease of which is related to chronic course. Currently, there is no robust prognosis biomarker. Cognitive dysfunction associated with the disease has been shown to predict treatment outcome. However, its cerebral substrate is poorly known. Verbal fluency (VF), which are broadly used neuropsychological test, assess the production of words according to a required criterion within a constrained time frame. During this task, subjects produce words within subcategories or “clusters” and occasionally “switch” to other clusters. The measurement of the cluster size and number of switches are relevant cognitive markers. Deep learning-based computational analysis method have been shown to improve the reproducibility and scalability of this measurement. The main objective of the current study was to characterize the cortical thickness (CT) surface-based morphometry (SBM) correlates of the switching and clustering scores in patients with MDD using an artificial intelligence empowered speech analysis system. The secondary objective was to compare those cognitive scores with the ones of the control group. Method The study included 26 depressed women and 25 matched in age and education level healthy females’ controls. All subjects underwent VF tests and had a structural Magnetic Resonance Imaging (MRI). The clustering and switching scores were assessed using the computational analysis method introduced by Linz et al ( https://ki-elements.de ). SBM was performed using SPM and CAT12 toolbox. Results In the depressed group, we observed a positive correlation between the switching score in semantic VF test and the CT, in few cortical areas. The main significant correlation was found in the left lingual gyrus (P = 0.003). The switching scores were lower in the depressed group in each VF task (P = 0.019 and P = 0.007). There was no difference between the two groups concerning the cluster size. Conclusion Our study revealed the relationship existing between the number of switches produced by depressed subjects in a semantic VF task and the CT in prefrontal regions and in more posterior areas. These results possibly suggest that switching and clustering scores assessment in VF tasks, and its cerebral correlates, may constitute potential prognosis biomarkers for depression. Although much work is still required, the establishment of such biomarkers has substantial implications for reducing the burden of the disease.

Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images (SDM-PSI).

Most methods for conducting meta-analysis of voxel-based neuroimaging studies do not assess whether effects are not null, but whether there is a convergence of peaks of statistical significance, and reduce the assessment of the evidence to a binary classification exclusively based on p-values (i.e., voxels can only be "statistically significant" or "non-statistically significant"). Here, we detail how to conduct a meta-analysis using Seed-based d Mapping with Permutation of Subject Images (SDM-PSI), a novel method that uses a standard permutation test to assess whether effects are not null. We also show how to grade the strength of the evidence according to a set of criteria that considers a range of statistical significance levels (from more liberal to more conservative), the amount of data or the detection of potential biases (e.g., small-study effect and excess of significance). To exemplify the procedure, we detail the conduction of a meta-analysis of voxel-based morphometry studies in obsessive-compulsive disorder, and we provide all the data already extracted from the manuscripts to allow the reader to replicate the meta-analysis easily. SDM-PSI can also be used for meta-analyses of functional magnetic resonance imaging, diffusion tensor imaging, position emission tomography and surface-based morphometry studies.

Cortical thickness of left Heschl’s gyrus correlates with hearing acuity in adults – A surface-based morphometry study

To date, research examining the relationship between brain structure and hearing acuity is sparse, especially given the context of a broad age range. To investigate this relationship, we applied an automated surface-based morphometry (SBM) approach (FreeSurfer) in this study to re-examine a sample of normal-hearing (n = 17) and hearing-impaired (n = 17) age- and education-matched adults, aged between 20 and 63 years (Alfandari et al., 2018). The SBM approach allows the disentanglement of cortical surface area (CSA) from cortical thickness (CT), the 2 independent constituents of cortical volume (CV). We extend the findings of Alfandari and colleagues by showing several clusters in auditory-related areas as well as in the left and right angular gyrus that showed reduced CT, CSA and CV in hearing-impaired compared to normal-hearing listeners. Nevertheless, none of the clusters found correlated significantly with hearing acuity, measured by pure-tone thresholds, in the 2 groups. An additional vertex-wise correlation analysis between hearing acuity and morphometric parameters over all participants revealed a single significant cluster encompassing the left Heschl’s gyrus. Higher hearing thresholds were associated with a thinner cortex within this cluster. Our results imply that hearing impairment is associated with reduced thickness in primary and secondary auditory cortex regions, those regions especially involved in perceiving and processing relevant speech cues. This decrease was observed not only in older but also in younger and middle-aged adults, independent of age-related decline in the cognitive domain and age-dependent whole-brain atrophy. Further, the results show the value added when considering CV, CT and CSA separately, relative to previous studies which have solely relied on voxel-based morphometry to investigate brain structure and hearing acuity across the lifespan.

Boys with autism spectrum disorder have distinct cortical folding patterns underpinning impaired self-regulation: a surface-based morphometry study.

Although impaired self-regulation (dysregulation) in autism spectrum disorder (ASD) garnered increasing awareness, the neural mechanism of dysregulation in ASD are far from conclusive. To complement our previous voxel-based morphometry findings, we estimated the cortical thickness, surface area, and local gyrification index based on the surface-based morphometry from structural MRI images in 85 ASD and 65 typically developing control (TDC) boys, aged 7-17years. Levels of dysregulation were measured by the sum of T-scores of Attention, Aggression, and Anxiety/Depression subscales on the Child Behavior Checklist. We found both ASD and TDC shared similar relationships between dysregulation and cortical folding patterns in the left superior and inferior temporal gyri and the left premotor cortex. Significant diagnosis by dysregulation interactions in cortical folding patterns were identified over the right middle frontal and right lateral orbitofrontal regions. The statistical significance of greater local gyrification index in ASD than TDC in several brain regions disappeared when the level of dysregulation was considered. The findings of shared and distinct neural correlates underpinning dysregulation between ASD and TDC may facilitate the development of targeted interventions in the future. The present work also demonstrates that inter-subject variations in self-regulation may explain some extents of ASD-associated brain morphometric differences, likely suggesting that dysregulation is one of the yardsticks for dissecting the heterogeneity of ASD.