The Default Mode Network in Autism

Metabolic control of type 1 diabetes in youth with autism spectrum disorder: A multicenter Diabetes-Patienten-Verlaufsdokumentation analysis based on 61 749 patients up to 20 years of age

BACKGROUND

A paucity of reports in the literature exists concerning the co-existence between autism spectrum disorder (ASD) and type 1 diabetes (T1D).

OBJECTIVE

To compare clinical characteristics, diabetes management and metabolic control in youth with T1D and ASD (T1D-ASD) with youth without ASD (T1D-non ASD).

METHODS

Using the German/Austrian diabetes patient follow-up registry, this study analyzed aggregated data from the last available year of observation for each patient with T1D, ages 1-20 with consistent data on insulin regimen and glycated hemoglobin (A1C), between January, 2005 and March, 2017.

RESULTS

From 61 749 patients, 150 (0.24%) were identified as T1D-ASD. Non-adjusted comparisons showed similar results for mean age at onset and duration of diabetes, but not for gender (male: T1D-ASD: 85.3%; T1D-non ASD: 52.8%; P < .001). Unadjusted comparisons showed no difference for severe hypoglycemia, diabetic ketoacidosis, insulin doses, insulin pump therapy, and body mass index. A statistical difference was observed for A1C (P-value .01) and in the number of blood glucose (SMBG) tests/day (median [interquartile range]: T1D-ASD 6.0 [4.4-7.0]; T1D-non ASD 5.0 [4.4-7.0]; P-value < .001). After adjusting for age, gender, duration of diabetes, and year of observation, only SMBG remained significant (P-value .003). T1D-ASD used psycho-stimulants (15.3% vs 2.2%; P-value < .001), antipsychotics (10.7% vs 0.6%; P-value < .001), and antidepressive medications (3.6% vs 0.7%; P-value < .001) more frequently.

CONCLUSION

Metabolic control was similar in the T1D-ASD group compared to T1D-non ASD despite their comorbidity. Awareness of ASD remains important in T1D treatment, as both conditions require long-term multi-disciplinary medical follow-up for optimal outcomes.

Disrupted Cerebrocerebellar Intrinsic Functional Connectivity in Young Adults with High-Functioning Autism Spectrum Disorder: A Data-Driven, Whole-Brain, High-Temporal Resolution Functional Magnetic Resonance Imaging Study

This study examines the resting-state functional-connectivity (RsFc) in young adults with high-functioning autism spectrum disorder (HF-ASD) using state-of-the-art fMRI data acquisition and analysis techniques. High temporal resolution fMRI using simultaneous multi-slice acquisition aided unbiased whole-brain connectome-wide multivariate pattern analysis (MVPA) techniques for assessing RsFc. MVPA revealed two clusters (Crus I/II and lobule IX) of abnormal connectivity in the cerebellum that are consistent with the notion of a triple representation of nonmotor processing in the cerebellum. Whole-brain seed-based RsFc analyses informed by these clusters showed significant under connectivity between the cerebellar and social, emotional, and language brain regions in the HF-ASD group compared to healthy controls. The results we report are coherent with existing structural, functional, and RsFc literature in autism, extend previous literature reporting cerebellar abnormalities in the neuropathology of autism, and highlight the cerebellum as a potential target for therapeutic, diagnostic, predictive, and prognostic developments in HF-ASD. The description of functional connectivity abnormalities reported in this study using whole-brain, data-driven analyses has the potential to crucially advance the development of ASD biomarkers, targets for therapeutic interventions, and neural predictors for measuring treatment response.

Abnormal Functional Connectivity of Resting State Network Detection Based on Linear ICA Analysis in Autism Spectrum Disorder

Some functional magnetic resonance imaging (fMRI) researches in autism spectrum disorder (ASD) patients have shown that ASD patients have significant impairment in brain response. However, few researchers have studied the functional structure changes of the eight resting state networks (RSNs) in ASD patients. Therefore, research on statistical differences of RSNs between 42 healthy controls (HC) and 50 ASD patients has been studied using linear independent component analysis (ICA) in this paper. Our researches showed that there was abnormal functional connectivity (FC) of RSNs in ASD patients. The RSNs with the decreased FC and increased FC in ASD patients included default mode network (DMN), central executive network (CEN), core network (CN), visual network (VN), self-referential network (SRN) compared to HC. The RSNs with the increased FC in ASD patients included auditory network (AN), somato-motor network (SMN). The dorsal attention network (DAN) in ASD patients showed the decreased FC. Our findings indicate that the abnormal FC in RSNs extensively exists in ASD patients. Our results have important contribution for the study of neuro-pathophysiological mechanisms in ASD patients.

Metabotropic glutamate receptor 5 tracer [18F]-FPEB displays increased binding potential in postcentral gyrus and cerebellum of male individuals with autism: a pilot PET study

Background

Autism is a neurodevelopmental disorder that is first manifested during early childhood. Postmortem experiments have identified significantly elevated expression of metabotropic glutamate receptor 5 (mGluR5) in cerebellar vermis and prefrontal cortex of individuals with autism.

Methods

In the current study we employed the mGluR5 tracer [¹⁸F]-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile ([¹⁸F]-FPEB) to quantify mGluR5 binding in vivo in adults with autism vs. healthy controls using positron emission tomography (PET).

Results

We identified significantly higher [¹⁸F]-FPEB binding potential in the postcentral gyrus and cerebellum of individuals with autism. There was a significant negative correlation between age and [¹⁸F]-FPEB binding potential in the cerebellum but not in the postcentral gyrus. In the precuneus, [¹⁸F]-FPEB binding potential correlated positively with the lethargy subscale score for the Aberrant Behavioral Checklist (ABC). In cerebellum, there were significant negative correlations between [¹⁸F]-FPEB binding potential and ABC total score, ABC hyperactivity subscale score, and the ABC inappropriate speech subscale score.

Conclusions

These novel findings demonstrate for the first time that mGluR5 binding is altered in critical brain areas of subjects with autism, suggesting abnormal glutamate signaling in these regions. Finally, the correlations between altered [¹⁸F]-FPEB binding potential in the cerebellum and precuneus suggest that some autistic symptoms may be influenced by abnormal glutamate signaling.