Repetitive and self-injurious behaviors: associations with caudate volume in autism and fragile X syndrome

Abstract

BackgroundFollowing from previous work suggesting that neurobehavioral features distinguish fragile X and idiopathic variants of autism, we investigated the relationships between four forms of repetitive behavior (stereotypy, self-injury, compulsivity, ritual behavior) and caudate nuclei volume in two groups: boys with fragile X syndrome, a subset of whom met criteria for autism, and a comparison group of boys with idiopathic autism.MethodsBilateral caudate nuclei volumes were measured in boys aged 3 to 6 years with fragile X syndrome (n = 41), the subset of boys with fragile X syndrome and autism (n = 16), and boys with idiopathic autism (n = 30). Repetitive behaviors were measured using the Repetitive Behavior Scales-Revised.ResultsFor boys with idiopathic autism, left caudate volume was modestly associated with self-injury, while both compulsive and ritual behaviors showed significant positive correlations with bilateral caudate nuclei volumes, replicating previous results. For boys with fragile X syndrome, there was no such association between caudate volume and compulsive behaviors. However, we did identify significant positive correlations between self-injury total scores and number of self-injury topographies with bilateral caudate nuclei volumes.ConclusionsThese findings suggest a specific role for the caudate nucleus in the early pathogenesis of self-injurious behavior associated with both idiopathic autism and fragile X syndrome. Results further indicate that the caudate may be differentially associated with compulsive behavior, highlighting the utility of isolating discrete brain-behavior associations within and between subtypes of autism spectrum disorder.

Multidisciplinary Assessment and Treatment of Self-Injurious Behavior in Autism Spectrum Disorder and Intellectual Disability: Integration of Psychological and Biological Theory and Approach

“…The caudate is a portion of the basal ganglia that is highly innervated by DA. In a recent study, bilateral caudate nuclei volumes were associated with SIB in boys with fragile X syndrome, whereas increased volume of the left caudate nucleus was associated with SIB in boys with idiopathic ASD, indicating possible involvement (Wolff et al 2013).…”

Modeling fragile X syndrome in the <i>Fmr1</i> knockout mouse

“…Perseveration and repetitive behaviors, such as hand flapping, are associated with the full mutation in FXS (33,35,131,132). In the five-choice serial reaction time task, Fmr1 KO mice demonstrated heightened perseveration and responding during novel rule acquisition, which normalized with training (119).…”

Naltrexone for Severe Eye-Gouging in Down Syndrome

“…Dysregulation of a number of neurotransmitters has been linked with SIB, including dopamine, endogenous opioid, serotonin, glutamate, and GABA systems (2). For example, the caudate nucleus, which is heavily innervated by dopaminergic neurons, has been shown to be abnormal in cases of SIB associated with a wide range of neurodevelopmental conditions (3). Glutamate works in a regulatory relationship with dopamine between the basal ganglia and prefrontal cortex and has been implicated in animal studies of SIB (4).…”