Huebner, Andrea R.

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.

BACKGROUND Type 1 diabetes (T1D) is a risk factor for dementia and structural brain changes. It remains to be determined whether transient insulin deprivation that frequently occurs in insulin-treated individuals with T1D alters brain function. METHODS We therefore performed functional and structural magnetic resonance imaging, magnetic resonance spectroscopy, and neuropsychological testing at baseline and following 5.4 ± 0.6 hours of insulin deprivation in 14 individuals with T1D and compared results with those from 14 age-, sex-, and BMI-matched nondiabetic (ND) participants with no interventions. RESULTS Insulin deprivation in T1D increased blood glucose, and β-hydroxybutyrate, while reducing bicarbonate levels. Participants with T1D showed lower baseline brain N-acetyl aspartate and myo-inositol levels but higher cortical fractional anisotropy, suggesting unhealthy neurons and brain microstructure. Although cognitive functions did not differ between participants with T1D and ND participants at baseline, significant changes in fine motor speed as well as attention and short-term memory occurred following insulin deprivation in participants with T1D. Insulin deprivation also reduced brain adenosine triphosphate levels and altered the phosphocreatine/adenosine triphosphate ratio. Baseline differences in functional connectivity in brain regions between participants with T1D and ND participants were noted, and on insulin deprivation further alterations in functional connectivity between regions, especially cortical and hippocampus-caudate regions, were observed. These alterations in functional connectivity correlated to brain metabolites and to changes in cognition. CONCLUSION Transient insulin deprivation therefore caused alterations in executive aspects of cognitive function concurrent with functional connectivity between memory regions and the sensory cortex. These findings have important clinical implications, as many patients with T1D inadvertently have periods of transient insulin deprivation. TRIAL REGISTRATION ClinicalTrials.gov NCT03392441. FUNDING Clinical and Translational Science Award (UL1 TR002377) from the National Center for Advancing Translational Science; NIH grants (R21 AG60139 and R01 AG62859); the Mayo Foundation.