Symons, Frank J.

ABSTRACTBackgroundSelf‐injurious behaviour (SIB) is a common problem among individuals with intellectual and developmental disabilities (IDDs) with important impacts on quality of life. Although some evidence suggests that SIB may increase with age, perhaps in a curvilinear pattern, this is primarily based on cross‐sectional studies. Therefore, the purpose of the current study was to conduct a prospective, longitudinal analysis of age‐related changes in a high‐risk cohort of children with developmental disabilities/delays.MethodsA total of 110 participants, between 2 and 12 years of age at enrolment (70% male), were followed for between 2 and 4 years. Caregivers completed the RBS‐EC SIB subscale annually, for a total of 317 assessments. The SIB total score, SIB interference ratings and endorsement of specific topographies were selected as dependent measures. Generalised linear models evaluating linear, quadratic and cubic age‐related changes and differences by intellectual disability (ID) status (no or mild ID vs. moderate to profound ID) were created for each outcome.ResultsFor SIB total scores, the model suggested complex developmental patterns that varied by degree of ID. For SIB interference ratings, the model suggested that individuals with moderate to profound ID showed relatively high and stable levels of SIB interference across ages, whereas individuals with no or mild ID showed an increasing trend with age. Patterns varied across the specific SIB topographies.DiscussionThe results suggest that age‐related changes in SIB are complex and may vary across topographies. Overall, the results are concerning in that they indicate a potentially increasing trend in frequency of SIB and its impact on daily activities as individuals approach adolescence, indicating the need for further longitudinal work across the lifespan.

AbstractBackgroundEmpirical evidence regarding the development of sensory responsivity in young children at high likelihood to develop autism spectrum disorder (ASD) remains relatively limited. It is unclear how sensory responsivity behaviors may change over time and impact later developmental outcomes. The goals of this study were to (a) characterize developmental trajectories of sensory responsivity across infancy (∼12 months), toddlerhood (∼24 months), and school age (6–11 years) in children at high and low familial likelihood for ASD; and (b) determine if sensory responsivity in infancy predicts adaptive and cognitive functioning at school age among children with ASD.MethodsGeneralized linear mixed effects models were used to examine scores from the Sensory Experiences Questionnaire in three groups of children including high‐likelihood children later diagnosed with ASD (HL‐ASD; n = 30), high‐likelihood children without ASD (HL‐Neg; n = 150), and low‐likelihood control children not meeting ASD diagnostic criteria (LL‐Neg; n = 94). Hierarchical linear regression was then used to examine the association between sensory responsivity scores in infancy and functional adaptive and cognitive outcomes at school age for children at high likelihood of ASD.ResultsDevelopment of sensory responsivity from infancy to later childhood is best estimated by the effects of chronological age and Group for Sensory Seeking and Hypo responsivity and the additional effect of the interaction of Group and chronological age for Total and Hyper responsivity. Early elevated Hypo responsivity and Sensory Seeking scores are negatively associated with later adaptive behavior but not cognitive level.ConclusionOverall, higher degrees of Sensory Seeking and Hypo sensory responsivity are detectable in autistic children's behavioral repertoires by 12 months of age and associate with reduced adaptive functioning in middle childhood. These results point to the potential importance of early detection and treatment implications of early sensory behaviors.

Abstract Assessing tactile function among children with intellectual, motor, and communication impairments remains a clinical challenge. A case control design was used to test whether children with global developmental delays (GDD; n = 20) would be more/less reactive to a modified quantitative sensory test (mQST) compared to controls (n = 20). Reactivity was indexed by blinded behavioral coding across vocal, facial, and gross motor responses during the mQST. On average the children with GDD were significantly more reactive than controls to most tactile sensory modalities including light touch (p = .034), pin prick (p = .008), cool (p = .039), pressure (p = .037), and repeated von Frey (p = .003). The results suggest the mQST approach was feasible and highlights the GDD sample was more reactive than controls to a range of stimuli.

The relation between somatosensory mechanisms and self-injury among children with neurologic impairments associated with developmental delay is not well understood. We evaluated the feasibility of procuring skin biopsies to examine epidermal nerve fiber density and reported self-injury. Following informed parental consent, epidermal skin biopsies were obtained from a distal leg site with no pre-existing skin damage from 11 children with global developmental delay (55% male; mean age = 36.8 months, 17-63 months). Visual microscopic examination and quantitative analyses showed extremely high epidermal nerve fiber density values for some children. Children with reported self-injury (5/11) had significantly ( P < .02) greater density values (138.8, standard deviation = 45.5) than children without self-injury (80.5, standard deviation = 17.5). Results from this novel immunohistologic analysis of skin in very young children with neurodevelopmental delays suggest it may be a useful tool to study peripheral innervation as a possible sensory risk factor for self-injury.

The aim of this preliminary case study series was to investigate epidermal innervation in pediatric patients with significant neurological impairment and self‐injurious behavior. We enrolled four pediatric patients with self‐injury (two males, two females; mean age 12y, range 9–14y) and used archival specimens from healthy, age‐matched children with typical development for comparison purposes. Epidermal nerve fiber density, peptide content, and mast cell degranulation patterns from non‐damaged skin were tested between the patients and the comparison group. The male patients with self‐injury had significantly increased epidermal nerve fiber densities, increased substance P positive fiber count and extensive mast cell degranulation compared with sex‐ and age‐matched individuals with typical development. Our case series shows for the first time altered peripheral innervation from non‐damaged tissue in children with significant self‐injury and developmental disability compared with a healthy comparison group. Establishing the role of peripheral nociceptive and immune modulatory neural pathways may offer new treatment avenues for this devastating neurobehavioral disorder.