Multimodal Brain Imaging Neural Mechanism Of The Co-occurrence Of Autistic Spectrum Disorder And Attention Deficit Hyperactivity Disorder

Symptoms of autism spectrum disorder(ASD)and attention deficit hyperactivity disorder(ADHD)often occur together.DSM-IV pointed out that ASD diagnosis was the exclusion criteria for ADHD,limiting the study of this common clinical cooccurrence.DSM-5 recognized this co-occurrence frequency in its revised diagnostic criteria and allowed comorbid diagnosis of ASD and ADHD for the first time.Although most studies to date have documented the separated developmental trajectories of ASD and ADHD,little was known about their simultaneous occurrence,and the underlying neural mechanisms were even less clear.Our project would be divided into three parts to explore the potential neurobiological mechanism of brain network and structure in ASD patients with ADHD Comorbidity using multi-modal neuroimaging data.1.This part aim to explore the characteristics of functional connectivity in the resting brain network and between networks in patients with ASD comorbid ADHD.Using resting functional magnetic resonance data from Autism Brain Imaging Data Exchange II(ABIDE?II)(N=339: ASD?co ADHD=79,ASD?non ADHD=83,TD=177),we found that the functional connectivity in default network(DMN)of ASD patients with ADHD was decreased and the functional connectivity between DMN and Somatomotor network was increased.The decrease of functional connectivity in the default network(DMN)was negatively correlated with the degree of autism characteristics in the whole sample of ASD patients and those with ASD and ADHD.Therefore,the dysfunction of default network(DMN)is the core feature of the co-occurrence of ASD and ADHD.2.This part aim to further explore the characteristic changes of gray matter volume in patients with ASD comorbid ADHD.After using the ABIDE?II database structure T1 data to strictly match the gender and age within each site(N=135: ASD?co ADHD=45,ASD?non ADHD=45,TD=45),it was found that increased grey matter volume of the right anterior cingulate cortex(ACC)and the left precentral gyrus,separately belonging to the default network(DMN)and the Somatomotor network,which proved that besides the abnormal functional connections(FC),the volume of gray matter in the default network(DMN)and Somatomotor network were also abnormal,further proving that the abnormality of default network and Somatomotor network is the core brain network of the co-occurrence of ASD and ADHD.3.Using single-site data to explore the abnormal characteristics of gray matter volume the co-occurrence of ASD and ADHD.The brain structure magnetic resonance imaging(s MRI)of children with ASD collected by Xinhua Hospital affiliated to Shanghai Jiaotong University were grouped according to the Chinese version of the SNAP-IV Rating Scale for Parental Deficit Hyperactivity Disorder(parent version)(N=101: ASD?co ADHD=40),ASD?non ADHD=40,TD=21),the results found that the Chinese Han ASD combined with ADHD children's DMN(left frontal lobe)gray matter volume and Somatomotor network(right inferior and middle temporal gyrus,the postcentral gyrus and left cerebellum)gray matter volume were damaged,although the specific location of gray matter volume change was different from that of European and American Caucasians,the gray matter volume of the right temporal lobe cluster was significantly negatively correlated with the age of the children in the disease group,further suggesting the DMN and Somatomotor network were the key neural networks for distinguishing children with the cooccurrence of ASD and ADHD from simple ASD children.In summary,the results of multimodal brain MRI data suggest that the default network and Somatomotor network are the key core networks for the co-occurrence of ASD and ADHD.Our results supported the existence of a clinically combined phenotype(ASD+ ADHD).It provided a key target for focused training,neuromodulation or pharmacotherapeutic approaches.