Biology subjects

Beggiato, A.

Publications and source records attributed to Beggiato, A..

3 recordsLinked to original sources

bioRxiv2019

Increased contrast of the grey-white matter boundary in the motor, visual and auditory areas in Autism Spectrum Disorders

The contrast of the interface between the cortical grey matter and the white matter is emerging as an important neuroimaging biomarker for several brain disorders. Differences in grey to white matter contrast could be related to abnormalities in neuronal migration or in intra-cortical myelination, and are an appealing biomarker for ASD. Two previous studies have reported differences in contrast between patients with autism spectrum disorder and non-autistic controls. We aimed at replicating this finding using open data from the ABIDE initiative, phases 1 and 2, gathering data from 2,148 subjects from 26 different centres and on 764 individuals from the EU-AIMS project (6 different centres). We used multiple linear regression to study the effect of the diagnosis of ASD on contrast, and 3 different strategies for controlling for multiple comparisons. We did not find statistically significant differences in the EU-AIMS dataset, and those that we found in the ABIDE dataset were due to a single centre. All the code necessary to replicate our analyses has been made available open source: https://github.com/neuroanatomy/GWPC.

neuroscience↗

bioRxiv2018

Reproducible functional connectivity alterations are associated with autism spectrum disorder

Despite the high clinical burden little is known about pathophysiology underlying autism spectrum disorder (ASD). Recent resting state functional magnetic resonance imaging (rs-fMRI) studies have found atypical synchronization of brain activity in ASD. However, no consensus has been reached on the nature and clinical relevance of these alterations. Here we address these questions in the most comprehensive, large-scale effort to date comprising evaluation of four large ASD cohorts. We followed a strict exploration and replication procedure to identify core rs-fMRI functional connectivity (degree centrality) alterations associated with ASD as compared to typically developing (TD) controls (ASD: N=841, TD: N=984). We then tested for associations of these imaging phenotypes with clinical and demographic factors such as age, sex, medication status and clinical symptom severity. We find reproducible patterns of ASD-associated functional hyper- and hypo-connectivity with hypo-connectivity being primarily restricted to sensory-motor regions and hyper-connectivity hubs being predominately located in prefrontal and parietal cortices. We establish shifts in between-network connectivity from outside to within the identified regions as a key driver of these abnormalities. The magnitude of these alterations is linked to core ASD symptoms related to communication and social interaction and is not affected by age, sex or medication status. The identified brain functional alterations provide a reproducible pathophysiological phenotype underlying the diagnosis of ASD reconciling previous divergent findings. The large effect sizes in standardized cohorts and the link to clinical symptoms emphasize the importance of the identified imaging alterations as potential treatment and stratification biomarkers for ASD.

neuroscience↗

bioRxiv2017

Cerebellar volume in autism: Meta-analysis and analysis of the ABIDE cohort

Cerebellar volume abnormalities have been often suggested as a possible endophenotype for autism spectrum disorder (ASD). We aimed at objectifying this possible alteration by performing a systematic meta-analysis of the literature, and an analysis of the Autism Brain Imaging Data Exchange (ABIDE) cohort. Our meta-analysis sought to determine a combined effect size of ASD diagnosis on different measures of the cerebellar anatomy, as well as the effect of possible factors of variability across studies. We then analysed the cerebellar volume of 328 patients and 353 controls from the ABIDE project. The meta-analysis of the literature suggested a weak but significant association between ASD diagnosis and increased cerebellar volume (p=0.049, uncorrected), but the analysis of ABIDE did not show any relationship. The studies in the literature were generally underpowered, however, the number of statistically significant findings was larger than expected. Although we could not provide a conclusive explanation for this excess of significant findings, our analyses would suggest publication bias as a possible reason. Finally, age, sex and IQ were important sources of cerebellar volume variability, however, independent of autism diagnosis.

neuroscience↗