Local Gyrification Index Research Articles

A gyrification analysis approach based on Laplace Beltrami eigenfunction level sets

An accurate measure of the complexity of patterns of cortical folding or gyrification is necessary for understanding normal brain development and neurodevelopmental disorders. Conventional gyrification indices (GIs) are calculated based on surface curvature (curvature-based GI) or an outer hull surface of the cortex (outer surface-based GI). The latter is dependent on the definition of the outer hull surface and a corresponding function between surfaces. In the present study, we propose the Laplace Beltrami-based gyrification index (LB-GI). This is a new curvature-based local GI computed using the first three Laplace Beltrami eigenfunction level sets. As with outer surface-based GI methods, this method is based on the hypothesis that gyrification stems from a flat surface during development. However, instead of quantifying gyrification with reference to corresponding points on an outer hull surface, LB-GI quantifies the gyrification at each point on the cortical surface with reference to their surrounding gyral points, overcoming several shortcomings of existing methods. The LB-GI was applied to investigate the cortical maturation profile of the human brain from preschool to early adulthood using the PING database. The results revealed more detail in patterns of cortical folding than conventional curvature-based methods, especially on frontal and posterior tips of the brain, such as the frontal pole, lateral occipital, lateral cuneus, and lingual. Negative associations of cortical folding with age were observed at cortical regions, including bilateral lingual, lateral occipital, precentral gyrus, postcentral gyrus, and superior frontal gyrus. The results also indicated positive significant associations between age and the LB-GI of bilateral insula, the medial orbitofrontal, frontal pole and rostral anterior cingulate regions. It is anticipated that the LB-GI will be advantageous in providing further insights in the understanding of brain development and degeneration in large clinical neuroimaging studies.

Cerebral cortical thickness and gyrification changes in first-episode psychoses and multi-episode schizophrenia.

Cortical thickness (CT) and local gyrification index (LGI) in psychotic disorders may show modifications that relate to clinical course. This observational study aimed to analyse such variables in patients with schizophrenia, compared to healthy controls (HCs). We compared CT and LGI of 18 patients with first-episode psychosis with that of 21 with multi-episode schizophrenia and 16 HCs. CT corrected for false-positive cases (Family-Wise Error Rate) showed a reduction in the multi-episode group compared to HCs in left temporal and parietal, and right temporal, parietal, occipital, and hippocampal cortices. Family-wise corrected LGI was increased in the left inferior and middle frontal cortices, and in the right fusiform gyrus, cingulate, lingual, and parahippocampal gyri in first onset patients compared to HCs. Increased LGI was absent from later stages of psychosis, suggesting that specific CT and LGI alterations may underlie different stages of illness.

Structural Changes of the Human Fetal Brain During the COVID-19 Pandemic

Background: Elevated maternal psychological distress during pregnancy is linked to adverse short- and long-term outcomes in the offspring. The potential deleterious effects of intensified levels of maternal distress during the COVID-19 pandemic on the developing fetal brain are currently unknown.Methods: We prospectively enrolled 202 pregnant women: 65 with negative COVID-19 diagnoses during the pandemic who underwent 92 fetal MRI scans, and 137 pre-pandemic controls who had 182 MRI scans. Multi-plane, multi-phase single shot fast spin echo T2-weighted images were acquired on a GE 1.5T MRI Scanner. High-resolution 3D models of the fetal brains were reconstructed, and volumes of six brain tissue types were calculated: cortical gray matter (CGM), white matter (WM), cerebellum, deep gray matter (DGM), brainstem, and hippocampus. Cortical folding measures, including brain surface area, local gyrification index (LGI), and sulcal depth were determined. At each MRI scan, maternal distress was assessed using validated stress, anxiety and depression scales. Generalized estimating equations (GEEs) were utilized to compare maternal distress measures, brain volume and cortical folding differences between pandemic and pre-pandemic cohorts.Findings: Stress and depression scores were significantly higher in the pandemic cohort (14.2 vs. 10.4 for stress; 5.9 vs. 4.2 for depression; pConclusion: We relate heightened maternal psychological distress with impaired fetal brain growth and delayed cerebral cortical gyrification in COVID-19 pandemic era pregnancies. The potential long-term neurodevelopmental consequences of altered fetal brain development in COVID-era pregnancies complicated by elevated maternal distress merit further study.Funding: This study was funded by National Institutes of Health (NHLBI R01 HL116585-01), Intellectual and Developmental Disabilities Research Center (IDDRC), and A. James & Alice B. Clark Foundation.Declaration of Interest: None to declare. Ethical Approval: These studies received ethical approval from Children's National Hospital Institutional Review Board (Protocol: 1373 and 14257).

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.

Altered Local Gyrification Index and Corresponding Functional Connectivity in Medication Free Major Depressive Disorder.

A lot of previous studies have documented that major depressive disorder (MDD) is a developmental disorder. The cortical surface measure, local gyrification index (LGI), can well reflect the fetal and early postnatal neurodevelopmental processes. Thus, LGI may provide new insight for the neuropathology of MDD. The previous studies only focused on the surface structural abnormality, but how the structural abnormality lead to functional connectivity changes is unexplored. In this study, we investigated LGI and corresponding functional connectivity difference in 28 medication-free MDD patients. We found significantly decreased LGI in left lingual gyrus (LING) and right posterior superior temporal sulcus (bSTS), and the changed LGI in bSTS was negatively correlated with disease onset age and anxiety scores. The following functional connectivity analyses identified decreased functional connectivities between LING and right LING, precentral gyrus, and middle temporal gyrus. The decreased functional connectivities were correlated with disease duration, onset, and depression symptoms. Our findings revealed abnormal LGI in LING and bSTS indicating that the abnormal developmental of visual and social cognition related brain areas may be an early biomarker for depression.

Changes in the anterior cingulate cortex in Crohn's disease: A neuroimaging perspective.

IntroductionEvidence suggests that Crohn's disease (CD) pathophysiology goes beyond the gastrointestinal tract and is also strongly associated with the brain. In particular, the anterior cingulate cortex (ACC), which plays an integral role in the first brain as part of the default mode network (DMN) and pain matrix, shows abnormalities using multiple neuroimaging modalities. This review summarizes nine related studies that investigated changes in the ACC using structural magnetic resonance imaging, resting‐state functional magnetic resonance imaging, and magnetic resonance spectroscopy.MethodsAn extensive PubMed literature search was conducted from 1980 to August 2020. In a review of the articles identified, particular attention was paid to analysis methods, technical protocol characteristics, and specific changes in the ACC.ResultsIn terms of morphology, a decrease in gray matter volume and cortical thickness was observed along with an increase in local gyrification index. In terms of function, functional connectivity (FC) within the DMN was increased. FC between the ACC and the amygdala was decreased. Higher amplitudes of low‐frequency fluctuation and graph theory results, including connectivity strength, clustering coefficient, and local efficiency, were detected. In terms of neurotransmitter changes, the concentrations of glutamate increased along with a decrease in gamma‐aminobutyric acid, providing a rational explanation for abdominal pain. These changes may be attributed to stress, pain, and negative emotions, as well as changes in gut microbiota.ConclusionsFor patients with CD, the ACC demonstrates structural, functional, and metabolic changes. In terms of clinical findings, the ACC plays an important role in the onset of depression/anxiety and abdominal pain. Therefore, successful modulation of this pathway may guide treatment.

Alteration of Cortical and Subcortical Structures in Children With Profound Sensorineural Hearing Loss.

Profound sensorineural hearing loss (SNHL) is an auditory disability associated with auditory and cognitive dysfunction. Due to distinct pathogenesis, some associated structural and functional changes within the brain have been investigated in previous studies, but whole-brain structural alterations are incompletely understood. We extended the exploration of neuroanatomic differences in whole-brain structure in children with profound SNHL who are primarily users of Chinese sign language (CSL). We employed surface-based morphometry (SBM) and subcortical analyses. T1-weighted magnetic resonance images of 26 children with profound SNHL and 27 age- and sex-matched children with normal hearing were analyzed. Compared with the normal control (NC) group, children with profound SNHL showed diverse structural changes in surface-based and subcortical analyses, including decreased cortical thickness in the left postcentral gyrus, superior parietal lobule, paracentral lobule, precuneus, the right transverse temporal gyri, and the middle temporal gyrus; a noticeable increase in the Local Gyrification Index (LGI) in the left precuneus and superior parietal lobule; and diverse changes in gray-matter volume (GMV) in different brain regions. Surface-based vertex analyses revealed regional contractions in the right thalamus, putamen, pallidum, and the brainstem of children with profound SNHL when compared with those in the NC group. Volumetric analyses showed decreased volumes of the right thalamus and pallidum in children with profound SNHL. Our data suggest that children with profound SNHL are associated with diffuse cerebral dysfunction to cortical and subcortical nuclei, and revealed neuroplastic reorganization in the precuneus, superior parietal lobule, and temporal gyrus. Our study provides robust evidence for changes in connectivity and structure in the brain associated with hearing loss.

Decreased cortical gyrification in patients with bipolar disorder.

An aberrant neural connectivity has been known to be associated with bipolar disorder (BD). Local gyrification may reflect the early neural development of cortical connectivity and has been studied as a possible endophenotype of psychiatric disorders. This study aimed to investigate differences in the local gyrification index (LGI) in each cortical region between patients with BD and healthy controls (HCs). LGI values, as measured using FreeSurfer software, were compared between 61 patients with BD and 183 HCs. The values were also compared between patients with BD type I and type II as a sub-group analysis. Furthermore, we evaluated whether there was a correlation between LGI values and illness duration or depressive symptom severity in patients with BD. Patients with BD showed significant hypogyria in various cortical regions, including the left inferior frontal gyrus (pars opercularis), precentral gyrus, postcentral gyrus, superior temporal cortex, insula, right entorhinal cortex, and both transverse temporal cortices, compared to HCs after the Bonferroni correction (p < 0.05/66, 0.000758). LGI was not associated with clinical factors such as illness duration, depressive symptom severity, and lithium treatment. No significant differences in cortical gyrification according to the BD subtype were found. BD appears to be characterized by a significant regionally localized hypogyria, in various cortical areas. This abnormality may be a structural and developmental endophenotype marking the risk for BD, and it might help to clarify the etiology of BD.

Long-term Air Pollution and Noise Exposures and Structural Parameters of the Default Mode Network in the 1000BRAINS Study

Background/Aim: While evidence suggests that long-term air pollution (AP) and noise may have negative effects on brain health and cognition, little is known about structural and functional changes in the brain networks that may underlie these associations. We investigated the association between AP and traffic noise exposures and structural parameters, including cortical thickness and the local gyrification index (lGI), of the Default Mode Network (DMN) in the brain, as it is important for resting-state brain function. Like what is seen in the DMN with aging, we hypothesized AP and noise exposures to be associated with decreased cortical thickness and more local atrophy (i.e., lower lGI). Methods: We used data from 559 participants of the 1000BRAINS study in Germany. Residential mean AP exposures (particulate matter [PM] 10, PM2.5, NO2, and accumulation mode particulate number concentration [PNAM]) were modeled for the years 2006-2008 using the validated EURAD chemistry transport model on a 1 km2 scale. Long-term traffic noise was modeled at participants’ homes according to European standards. Cortical thickness and lGI values in the left and right medial prefrontal cortex, posterior cingulate cortex, and inferior parietal lobule of the DMN were calculated from T1-weighted structural brain images collected between 2011 and 2015. Associations between environmental exposures and brain parameters were estimated using linear regression models, adjusting for demographic and lifestyle characteristics. Results: Exposure to PM10, PM2.5 and PNAM was weakly associated with decreased cortical thickness in the left prefrontal cortex (e.g., -0.02 [95% Confidence-Interval: -0.03, 0.00] mm per 3.65 µg/m3 increase in PM10). No associations were observed for AP and lGI or between traffic noise exposure and either DMN parameter. Conclusion: Weak associations between AP and structural parameters of the DMN in the brain were observed, but further studies are needed to validate this result.

Developmental Alterations in Cortical Organization and Socialization in Adolescents Who Sustained a Traumatic Brain Injury in Early Childhood.

This study investigated patterns of cortical organization in adolescents who had sustained a traumatic brain injury (TBI) during early childhood to determine ways in which early head injury may alter typical brain development. Increased gyrification in other patient populations is associated with polymicrogyria and aberrant development, but this has not been investigated in TBI. Seventeen adolescents (mean age = 14.1 ± 2.4) who sustained a TBI between 1-8 years of age, and 17 demographically-matched typically developing children (TDC) underwent a high-resolution, T1-weighted 3-Tesla magnetic resonance imaging (MRI) at 6-15 years post-injury. Cortical white matter volume and organization was measured using FreeSurfer's Local Gyrification Index (LGI). Despite a lack of significant difference in white matter volume, participants with TBI demonstrated significantly increased LGI in several cortical regions that are among those latest to mature in normal development, including left parietal association areas, bilateral dorsolateral and medial frontal areas, and the right posterior temporal gyrus, relative to the TDC group. Additionally, there was no evidence of increased surface area in the regions that demonstrated increased LGI. Higher Vineland-II Socialization scores were associated with decreased LGI in right frontal and temporal regions. The present results suggest an altered pattern of expected development in cortical gyrification in the TBI group, with changes in late-developing frontal and parietal association areas. Such changes in brain structure may underlie cognitive and behavioral deficits associated with pediatric TBI. Alternatively, increased gyrification following TBI may represent a compensatory mechanism that allows for typical development of cortical surface area, despite reduced brain volume.

Temporally and sex-specific effects of maternal perinatal stress on offspring cortical gyrification and mood in young adulthood.

Maternal stress during pregnancy and shortly thereafter is associated with altered offspring brain development that may increase risk of mood and anxiety disorders. Cortical gyrification is established during the prenatal period and the first 2 years of life and is altered in psychiatric disorders. Here, we sought to characterize the effects of perinatal stress exposure on offspring gyrification patterns and mood dysregulation in young adulthood. Participants included 85 young adults (56.5% women; 23–24 years) from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) with perinatal stress data across four distinct timepoints and structural MRI data from young adulthood. Perinatal stress exposure was measured as maternal stress during first and second half of pregnancy, first 6 months, and 6–18 months after birth. Cortical gyrification and mood dysregulation were quantified using local gyrification index (LGI), computed with Freesurfer, and the Profile of Mood States questionnaire, respectively. Perinatal stress predicted cortical gyrification in young adulthood, and its timing influenced location, direction, and sex‐specificity of effects. In particular, whereas early prenatal stress was associated with sex‐dependent medium‐to‐large effects in large temporal, parietal, and occipital regions (f 2 = 0.19–0.38, p < .001), later perinatal stress was associated with sex‐independent small‐to‐medium effects in smaller, more anterior regions (f 2 = 0.10–0.19, p < .003). Moreover, in females, early prenatal stress predicted higher LGI in a large temporal region, which was further associated with mood disturbance in adulthood (r = 0.399, p = .006). These findings point out the long‐term implications of perinatal stress exposure for cortical morphology and mood dysregulation.

Cortical gyrification and its relationships with molecular measures and cognition in children with the FMR1 premutation

Neurobiological basis for cognitive development and psychiatric conditions remains unexplored in children with the FMR1 premutation (PM). Knock-in mouse models of PM revealed defects in embryonic cortical development that may affect cortical folding. Cortical-folding complexity quantified using local gyrification index (LGI) was examined in 61 children (age 8–12 years, 19/14 male/female PM carriers, 15/13 male/female controls). Whole-brain vertex-wise analysis of LGI was performed for group comparisons and correlations with IQ. Individuals with aberrant gyrification in 68 cortical areas were identified using Z-scores of LGI (hyper: Z ≥ 2.58, hypo: Z ≤ − 2.58). Significant group-by-sex-by-age interaction in LGI was detected in right inferior temporal and fusiform cortices, which correlated negatively with CGG repeat length in the PM carriers. Sixteen PM boys (hyper/hypo: 7/9) and 10 PM girls (hyper/hypo: 2/5, 3 both) displayed aberrant LGI in 1–17 regions/person while 2 control boys (hyper/hypo: 0/2) and 2 control girls (hyper/hypo: 1/1) met the same criteria in only 1 region/person. LGI in the precuneus and cingulate cortices correlated positively with IQ scores in PM and control boys while negatively in PM girls and no significant correlation in control girls. These findings reveal aberrant gyrification, which may underlie cognitive performance in children with the PM.

Cortical Thinning and Ventricle Enlargement in Neuromyelitis Optica Spectrum Disorders.

Background: In neuromyelitis optica spectrum disorders (NMOSDs), inflammation is not the sole driver of accumulation of disability; neurodegeneration is another important pathological process. We aim to explore different patterns of cortical atrophy and ventricular enlargement in NMOSD.Methods: We retrospectively analyzed a cohort of 230 subjects, comprising 55 healthy controls (HCs), 85 multiple sclerosis (MS), and 90 NMOSD patients from Tianjin Medical University General Hospital and Beijing Tiantan Hospital. Different compartments of the brain (total gray, cortex, subcortex gray, and ventricle volume) were evaluated with the FreeSurfer. Multiple linear regressions were adopted to explore associations between cortex volume and predict factors.Results: Compared with HCs, NMOSD, and MS displayed an enlarged lateral and third ventricle (p < 0.001), whereas expansion of the fourth ventricle was observed in MS rather than NMOSD (p = 0.321). MS and NMOSD patients exhibited cortical thinning in comparison with HCs. However, pronounced cortical atrophy were only significant in pre-cuneus, parahippocampal, and lateral occipital lobe between MS and NMOSD. Patients with NMOSD had decreased local gyrification index in orbitofrontal and pre-cuneus lobe, and reduced pial surface area. Linear regression analysis revealed cortex volume were predicated by advanced age (standardized β = −0.404, p = 0.001) as well as prolonged disease history (standardized β = −0.311, p = 0.006).Conclusion: NMOSD exhibited global cortex atrophy with enlarged lateral and third ventricles. Moreover, cortex volume is associated with age and disease duration.

Brain gyrification in wild and domestic canids: Has domestication changed the gyrification index in domestic dogs?

Over the last 15 years, research on canid cognition has revealed that domestic dogs possess a surprising array of complex sociocognitive skills pointing to the possibility that the domestication process might have uniquely altered their brains; however, we know very little about how evolutionary processes (natural or artificial) might have modified underlying neural structure to support species-specific behaviors. Evaluating the degree of cortical folding (i.e., gyrification) within canids may prove useful, as this parameter is linked to functional variation of the cerebral cortex. Using quantitative magnetic resonance imaging to investigate the impact of domestication on the canine cortical surface, we compared the gyrification index (GI) in 19 carnivore species, including six wild canid and 13 domestic dog individuals. We also explored correlations between global and local GI with brain mass, cortical thickness, white and gray matter volume and surface area. Our results indicated that GI values for domestic dogs are largely consistent with what would be expected for a canid of their given brain mass, although more variable than that observed in wild canids. We also found that GI in canids is positively correlated with cortical surface area, cortical thickness and total cortical gray matter volumes. While we found no evidence of global differences in GI between domestic and wild canids, certain regional differences in gyrification were observed.

Quantitative MRI-Based Analysis Identifies Developmental Limbic Abnormalities in PCDH19 Encephalopathy.

Protocadherin-19 (PCDH19) is a calcium dependent cell-adhesion molecule involved in neuronal circuit formation with prevalent expression in the limbic structures. PCDH19-gene mutations cause a developmental encephalopathy with prominent infantile onset focal seizures, variably associated with intellectual disability and autistic features. Diagnostic neuroimaging is usually unrevealing. We used quantitative MRI to investigate the cortex and white matter in a group of 20 PCDH19-mutated patients. By a statistical comparison between quantitative features in PCDH19 brains and in a group of age and sex matched controls, we found that patients exhibited bilateral reductions of local gyrification index (lGI) in limbic cortical areas, including the parahippocampal and entorhinal cortex and the fusiform and lingual gyri, and altered diffusivity features in the underlying white matter. In patients with an earlier onset of seizures, worse psychiatric manifestations and cognitive impairment, reductions of lGI and diffusivity abnormalities in the limbic areas were more pronounced. Developmental abnormalities involving the limbic structures likely represent a measurable anatomic counterpart of the reduced contribution of the PCDH19 protein to local cortical folding and white matter organization and are functionally reflected in the phenotypic features involving cognitive and communicative skills as well as local epileptogenesis.

Altered structural cerebral cortex in children with Tourette syndrome

PurposeIn this study, we used magnetic resonance imaging (MRI) to investigate the anatomical alterations of cerebral cortex in children with Tourette syndrome (TS) and explore whether such deficits were related with their clinical symptoms. MethodsAll subjects were scanned in a 3.0T MRI scanner with three-dimensional T1-weighted images (3DT1WI). Then, some surface-based features were extracted by using the FreeSurfer software. After that, the between-group differences of those features were assessed. ResultsSixty TS patients and 52 age- and gender-matched healthy control were included in this study. Surface-based analyses revealed altered cortical thickness, cortical sulcus, cortical curvature and local gyrification index (LGI) in TS group compared with healthy controls. The brain regions with significant-group differences in cortical thickness included postcentral gyrus, superiorparietal gyrus, rostral anterior cingulate cortex in the left hemisphere and frontal pole, lateral occipital gyrus, inferior temporal gyrus in the right hemisphere. In addition, the superior temporal gyrus, medial orbitofrontal gyrus, supramarginal gyrus, medial orbitofrontal gyrus, superiorparietal gyrus and lateral occipital gyrus showed significant between-group differences for cortical sulcus. Moreover, the brain regions with significant between-group differences in cortical curvature were located in caudal anterior cingulate cortex, supramarginal gyrus, inferior parietal gyrus and lateral occipital gyrus. The alteration of LGI were most prominent in the inferior temporal gyrus and insula. Additionally, there was no statistical difference in brain surface area for TS children compared with controls. ConclusionThe results of this study revealed that cortical thickness, sulcus, cortical curvature and LGI were changed in multiple brain regions for children with TS.

Analysis of local gyrification index using a novel shape-adaptive kernel and the standard FreeSurfer spherical kernel – evidence from chronic schizophrenia outpatients

Schizophrenia can be considered a brain disconnectivity condition related to aberrant neurodevelopment that causes alterations in the brain structure, including gyrification of the cortex. Literature findings on cortical folding are incoherent: they report hypogyria in the frontal, superior-parietal and temporal cortices, but also frontal hypergyria. This discrepancy in local gyrification index (LGI) results could be due to the commonly used spherical kernel (Freesurfer), which is a method of analysis that is still not spatially precise enough. In this study we would like to test the spatial accuracy of a novel method based on a shape-adaptive kernel (Cmorph). The analysis of differences in gyrification between chronic schizophrenia outpatients (n = 30) and healthy controls (n = 30) was conducted with two methods: Freesurfer LGI and Cmorph LGI. Widespread differences in the LGI between schizophrenia outpatients and healthy controls were found using both methods. Freesurfer showed hypogyria in the superior temporal gyrus and the right temporal pole; it also showed hypergyria in the rostral-middle-frontal cortex in schizophrenia outpatients. In comparison, Cmorph revealed that hypergyria is equally represented as hypogyria in orbitofrontal and central brain regions. The clusters from Cmorph were smaller and distributed more broadly, covering all lobes of the brain. The presented evidence from disrupted cortical folding in schizophrenia indicates that the shape-adaptive kernel approach has a potential to improve the knowledge on the disrupted cortical folding in schizophrenia; therefore, it could be a valuable tool for further investigation on big sample size.

Associations of Air Pollution and Noise with Local Brain Structure in a Cohort of Older Adults.

Background:Despite the importance of understanding associations of air pollution and noise exposure with loss of neurocognitive performance, studies investigating these exposures and local brain structure are limited.Objective:We estimated associations of residential air pollution and noise exposures with neurocognitive test performance and the local gyrification index (lGI), a marker for local brain atrophy, among older adults.Methods:For participants from the population-based 1000BRAINS study, based on the German Heinz Nixdorf Recall study, we assessed residential exposures to particulate matter (, , ), accumulation mode particle number (), and nitrogen oxides (, ), using land-use regression and chemistry transport models. Weighted 24-h and nighttime noise were modeled according to the European noise directive. We evaluated associations of air pollution and noise exposure at the participants’ 2006–2008 residential addresses with neurocognitive test performance and region-specific lGI values () from magnetic resonance imaging, both assessed in 2011–2015, using linear regression and adjusting for demographic and personal characteristics.Results:Air pollution and noise were associated with language and short-term/working memory and with local atrophy of the fronto–parietal network (FPN), a functional resting-state network associated with these cognitive processes. For example, per , local brain atrophy was more pronounced in the posterior brain regions of the FPN, with a [95% confidence interval (CI): , 0.00] lower lGI. In contrast, in the anterior regions of the FPN, weighted 24-h and nighttime noise were associated with less local brain atrophy [e.g., 0.02 (95% CI: 0.00, 0.04) for (A) 24-h noise].Conclusions:Air pollution and noise exposures were associated in opposite directions with markers of local atrophy of the FPN in the right brain hemisphere in older adults, suggesting that both chronic air pollution and noise exposure may influence the physiological aging process of the brain. https://doi.org/10.1289/EHP5859

M55. STRUCTURAL CHANGES RELEVANT TO MUSICAL DEFICITS IN SCHIZOPHRENIA

BackgroundMusic is a shared experience in human culture. The ability to perceive, enjoy, and produce music is closely related to a fundamental element of human cognition. We previously reported that patients with schizophrenia have musical disability compared to healthy comparison. Several replications have shown that patients with schizophrenia have low musical ability that correlates with poor cognitive functions and severe psychiatric symptoms. We also reported that thinner cortical thickness in the left temporal, parietal, and inferior frontal regions is associated with lower musical ability in schizophrenia. Next, we sought to investigate diffusion tensor images (DTI) and local gyrification index (LGI) in patients with schizophrenia.MethodsTwenty-two right-handed patients with schizophrenia (12 males and 10 females, mean age = 45.9 years) and 20 right-handed healthy control subjects (13 males and 7 females, mean age = 42.8 years) consented to participate in this study. We measured musical ability, cognitive functions, and clinical assessments using the Montreal Battery for Evaluation of Amusia (MBEA), Brief Assessment of Cognition in Schizophrenia (BACS), and Positive and Negative Syndrome Scale (PANSS), respectively. We employed automatic probabilistic tractography DTI analysis using TRActs Constrained by UnderLying Anatomy (TRACULA) available in the Freesurfer software for the reconstruction of major tract bundles. The LGI was measured by quantifying the gyrification in spherical three-dimensional regions of interest by the Freesurfer.ResultsWhole-tract diffusion characteristics in patients with schizophrenia and controls were significantly different. Fractional anisotropy (FA) was lower for patients with schizophrenia compared to controls in the left superior longitudinal fasciculus - parietal endings (slfp) (p < 0.001), left cingulum - angular bundle (cab) (p < 0.001), and corpus callosum - forceps minor (fminor) (p < 0.001). We found significant correlation between musical abilities and FA alterations in slfp in both controls and patients with schizophrenia. While lower musical ability corresponds to lower FA in slfp of controls (r = -0.572, p = 0.013), it is associated with higher FA in the slfp of patients with schizophrenia (r = 0.515, p = 0.021). We did not reveal any significant correlation of musical ability to LGI in patients with schizophrenia. In controls, the correlation of musical ability to LGI in parahippocampal region after adjusting for age, sex, and years of musical training.DiscussionThis study shows that TRACULA can be used for the detection of decrements in several DTI tracts including the left slfp, left cab, and fminor in patients with schizophrenia. It revealed that while lower musical ability correlates with lower FA values in the left slfp in controls, it is associated with higher FA values in the same region in patients with schizophrenia. This contradictory finding in controls and patients with schizophrenia with regard to white matter pathology may reflect left supramarginal region malfunction resulting in cortical pathology in patients with schizophrenia. The data suggest that patients with schizophrenia may be more susceptible to changes in cortical thickness in the supramarginal region, and white matter alteration in the left slfp. Further study is needed to confirm the results. The characteristics of grey and white matter in the left parietal region which are relevant to musical ability may provide insight into pathological progression in patients with schizophrenia.

Cortical complexity and gyrification patterns in Parkinson’s disease

This study aimed to investigate the cortical complexity and gyrification patterns in Parkinson's disease (PD) using local fractional dimension (LFD) and local gyrification index (LGI), respectively. In a cross-sectional study, LFD and LGI in 60 PD patients without dementia and 56 healthy controls (HC) were investigated using brain structural MRI data. LFD and LGI were estimated using the Computational Anatomy Toolbox (CAT12) and statistically analyzed between groups on a vertex level using statistical parametric mapping 12 (SPM12). Additionally, correlations between structural changes and clinical indices were further examined. PD patients showed widespread LFD reductions mainly in the left pre- and postcentral cortex, the left superior frontal cortex, the left caudal middle frontal cortex, the bilaterally superior parietal cortex and the right superior temporal cortex compared to HC. For LGI, there was no significant difference between PD and HC. In PD patients group, a significant negative correlation was found between LFD of the left postcentral cortex and duration of illness (DOI). Our results of widespread LFD reductions, but not LGI, indicate that LFD may provide a more sensitive diagnostic biomarker and encode specific information of PD. The significant negative correlation between LFD of the left postcentral cortex and DOI suggests that LFD may be a biomarker to monitor disease progression in PD.