Structural brain abnormalities in children and adolescents with comorbid autism spectrum disorder and attention-deficit/hyperactivity disorder

Abstract

Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) share high rates of comorbidity, with the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition now acknowledging the comorbid diagnosis of ASD and ADHD. Although structural abnormalities in the prefrontal cortex, cerebellum, and basal ganglia occur in both ASD and ADHD, no structural studies have focused exclusively on patients with comorbid ASD and ADHD. We thus aimed to clarify the structural features and developmental changes in patients with comorbid ASD and ADHD in a relatively large sample from two sites. Ninety-two patients were age-matched to 141 typically developing (TD) controls (age range: 5-16 years) and assessed for volumetric characteristics using structural magnetic resonance imaging (i.e. surface-based morphometry). While there were no significant differences in prefrontal cortex, cerebellum, and basal ganglia volumes, patients with ASD and ADHD exhibited significantly lower left postcentral gyrus volumes than TD controls. We observed significantly lower postcentral gyrus volumes exclusively in children and preadolescents, and not in adolescents. Our findings suggest that abnormal somatosensory, attributed to delayed maturation of the left postcentral gyrus, leads to the core symptoms experienced by patients with comorbid ASD and ADHD.

Sex differences in structural brain asymmetry of children with autism spectrum disorders

“…Concerning the postcentral gyrus, volume abnormalities reported in this brain region in ASD have been inconsistent [31]. Mizuno et al [31] reported decreased left postcentral gyrus volume in ASD , while Brieber et al [32] described increased volume in this brain region in patients with ASD comparing with TDs. This may be due to the small sample sizes, the different proportions of females with ASD, and the different image processing techniques among different studies.…”

ADHD: Reviewing the Causes and Evaluating Solutions

“…This was observed through magnetic resonance imaging in both children and preadolescents, but was absent in adolescents. The authors suggested that pathophysiology in these comorbid patients may be related to somatosensory deficits and delayed maturation in this area [ 105 ].…”

Neuroimaging of Basal Ganglia in Neurometabolic Diseases in Children

“…Abnormalities in the basal ganglia were found in some psychiatric disorders (e.g., attention deficit hyperactivity disorder; ADHD). The prefrontal cortex and the basal ganglia (particularly the caudate nucleus) exhibit increased volumes [ 51 , 52 , 53 , 54 ].…”