title: Atypical within- and between-hemisphere motor network functional connections in children with developmental coordination disorder and attention-deficit/hyperactivity disorder.
abstract: Developmental coordination disorder (DCD) and attention-deficit hyperactivity disorder (ADHD) are highly comorbid neurodevelopmental disorders; however, the neural mechanisms of this comorbidity are poorly understood. Previous research has demonstrated that children with DCD and ADHD have altered brain region communication, particularly within the motor network. The structure and function of the motor network in a typically developing brain exhibits hemispheric dominance. It is plausible that functional deficits observed in children with DCD and ADHD are associated with neurodevelopmental alterations in within- and between-hemisphere motor network functional connection strength that disrupt this hemispheric dominance. We used resting-state functional magnetic resonance imaging to examine functional connections of the left and right primary and sensory motor (SM1) cortices in children with DCD, ADHD and DCD + ADHD, relative to typically developing children. Our findings revealed that children with DCD, ADHD and DCD + ADHD exhibit atypical within- and between-hemisphere functional connection strength between SM1 and regions of the basal ganglia, as well as the cerebellum. Our findings further support the assertion that development of atypical motor network connections represents common and distinct neural mechanisms underlying DCD and ADHD. In children with DCD and DCD + ADHD (but not ADHD), a significant correlation was observed between clinical assessment of motor function and the strength of functional connections between right SM1 and anterior cingulate cortex, supplementary motor area, and regions involved in visuospatial processing. This latter finding suggests that behavioral phenotypes associated with atypical motor network development differ between individuals with DCD and those with ADHD.
authors.affiliation: Medical Science, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: McLeod
authors.affiliation: Department of Paediatrics, University of Calgary, Calgary, Alberta, Canada; Owerko Centre at the Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; Behavioural Research Unit, Alberta Children's Hospital, Calgary, Alberta, Canada.
authors.forename: Lisa Marie
authors.initials: LM
authors.lastname: Langevin
authors.affiliation: Department of Paediatrics, University of Calgary, Calgary, Alberta, Canada; Owerko Centre at the Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada; Behavioural Research Unit, Alberta Children's Hospital, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Deborah
authors.initials: D
authors.lastname: Dewey
authors.affiliation: Department of Radiology, University of Calgary, Calgary, Alberta, Canada; Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada; Seaman Family MR Research Centre, University of Calgary, Calgary, Alberta, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Bradley G
authors.initials: BG
authors.lastname: Goodyear
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002648:Child; D015897:Comorbidity; D063132:Connectome / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019957:Motor Skills Disorders / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D066191:Sensorimotor Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: Attention-deficit/hyperactivity disorder; Developmental coordination disorder; Motor network; Resting-state fMRI