Inhibitory control in children and adolescents with paediatric-onset obsessive-compulsive disorder - An fMRI study

BackgroundThe pathophysiology of obsessive-compulsive disorder (OCD) appears to involve dysfunctions in brain circuits underlying sensorimotor, cognitive, affective, and motivational processes. One area of dysfunction observed is disruption in inhibitory motor control. While functional magnetic resonance imaging (fMRI) has revealed associated alterations at the brain network level in adults, studies in pediatric OCD has yielded inconsistent results. MethodsThis task-based fMRI study examined executive motor control in 65 unmedicated paediatric OCD patients and 58 age- and sex-matched healthy controls. Participants were aged eight to 17 years and performed a stop-signal task during whole-brain 3 Tesla fMRI. In addition to whole-brain analyses, we performed a region-of-interest analysis, focusing on brain regions subserving inhibitory motor control during the stop-signal task. ResultsThe paediatric patients with OCD showed comparable task performance and inhibition abilities to healthy controls. However, during successful inhibition, patients with paediatric OCD showed increased activation in the superior frontal sulcus, dorsomedial prefrontal cortex and dorsal anterior cingulate cortex as compared to healthy controls. ConclusionOur behavioural findings indicate typical inhibitory motor control proficiency in paediatric OCD patients. This proficiency in completing a stop-signal task was associated with increased brain activation pattern in brain areas resembling patterns observed in adult patients with OCD, suggesting compensatory mechanisms. These findings, obtained in a large sample of unmedicated children and adolescents, contribute to the notion of early neural impairment in paediatric OCD.