14 research outputs found
Attentional Disengagement and the Locus Coeruleus – Norepinephrine System in Children With Autism Spectrum Disorder
Background: Differences in non-social attentional functions have been identified as among the earliest features that distinguish infants later diagnosed with autism spectrum disorder (ASD), and may contribute to the emergence of core ASD symptoms. Specifically, slowed attentional disengagement and difficulty reorienting attention have been found across the lifespan in those at risk for, or diagnosed with, ASD. Additionally, the locus coeruleus-norepinephrine (LC-NE) system, which plays a critical role in arousal regulation and selective attention, has been shown to function atypically in ASD. While activity of the LC-NE system is associated with attentional disengagement and reorienting in typically developing (TD) individuals, it has not been determined whether atypical LC-NE activity relates to attentional disengagement impairments observed in ASD.
Objective: To examine the relationship between resting pupil diameter (an indirect measure of tonic LC-NE activation) and attentional disengagement in children with ASD.
Methods: Participants were 21 school-aged children with ASD and 20 age- and IQ-matched TD children. The study consisted of three separate experiments: a resting eye-tracking task and visual and auditory gap-overlap paradigms. For the resting eye-tracking task, pupil diameter was monitored while participants fixated a central crosshair. In the gap-overlap paradigms, participants were instructed to fixate on a central stimulus and then move their eyes to peripherally presented visual or auditory targets. Saccadic reaction times (SRT), percentage of no-shift trials, and disengagement efficiency were measured.
Results: Children with ASD had significantly larger resting pupil size compared to their TD peers. The groups did not differ for overall SRT, nor were there differences in SRT for overlap and gap conditions between groups. However, the ASD group did evidence impairments in disengagement (larger step/gap effects, higher percentage of no-shift trials, and reduced disengagement efficiency) compared to their TD peers. Correlational analyses showed that slower, less efficient disengagement was associated with increased pupil diameter.
Conclusion: Consistent with prior reports, children with ASD show significantly larger resting pupil diameter, indicative of atypically elevated tonic LC-NE activity. Associations between pupil size and measures of attentional disengagement suggest that atypically increased tonic activation of the LC-NE system may be associated with poorer attentional disengagement in children with ASD
Equivalent Behavioral Facilitation to Tactile Cues in Children with Autism Spectrum Disorder
The alerting network, a subcomponent of attention, enables humans to respond to novel information. Children with ASD have shown equivalent alerting in response to visual and/or auditory stimuli compared to typically developing (TD) children. However, it is unclear whether children with ASD and TD show equivalent alerting to tactile stimuli. We examined (1) whether tactile cues affect accuracy and reaction times in children with ASD and TD, (2) whether the duration between touch-cues and auditory targets impacts performance, and (3) whether behavioral responses in the tactile cueing task are associated with ASD symptomatology. Six- to 12-year-olds with ASD and TD participated in a tactile-cueing task and were instructed to respond with a button press to a target sound /a/. Tactile cues were presented at 200, 400, and 800 ms (25% each) prior to the auditory target. The remaining trials (25%) were presented without tactile cues. Findings suggested that both groups showed equivalent alerting responses to tactile cues. Additionally, all children were faster to respond to auditory targets at longer cue-target intervals. Finally, there was an association between rate of facilitation and RRB scores in all children, suggesting that patterns of responding to transient phasic cues may be related to ASD symptomatology
A Magnetic Resonance Spectroscopy Study of Superior Visual Search Abilities in Children with Autism Spectrum Disorder
Although diagnosed on the basis of deficits in social communication and interaction, autism spectrum disorder (ASD) is also characterized by superior performance on a variety of visuospatial tasks, including visual search. In neurotypical individuals, region-specific concentrations of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) are associated with individual differences in attention and perception. While it has been hypothesized that ASD may be associated with an excitatory-inhibitory imbalance, it remains unclear how this may contribute to accelerated visual search performance in individuals with ASD. To investigate this, 21 children with ASD and 20 typically developing children participated in a visual search task and a magnetic resonance spectroscopy study to detect neurochemical concentrations, including GABA. Region-specific neurochemicals were examined in the right frontal eye fields, right temporal-parietal junction (rTPJ), and bilateral visual cortex (VIS). GABA concentrations did not differ between groups; however, in children with ASD, greater GABA concentration in the VIS was related to more efficient search. Additionally, lower VIS GABA levels were also associated with increased social impairment. Finally, we found reduced N-acetyl aspartate, total creatine, glutamate and glutamine (Glx), GABA/Glx in the rTPJ, suggestive of neuronal dysfunction in a critical network hub. Our results show that GABA concentrations in the VIS are related to efficient search in ASD, thus providing further evidence of enhanced discrimination in ASD. Autism Res 2020, 13: 550-562. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Children with autism spectrum disorder (ASD) often perform better than their non-ASD peers on visual search tasks; however, it is unclear how they achieve this superior performance. Using magnetic resonance spectroscopy to measure neurochemicals in the brain, we found that the level of one, gamma-aminobutyric acid, in the visual cortex was directly related to search abilities in children with ASD. These results suggest that faster search may relate to enhanced perceptual functioning in children with ASD
Associations Among Referral Concerns, Screening Results, and Diagnostic Outcomes of Young Children Assessed in a Statewide Early Autism Evaluation Network
Objectives
To examine associations between referral concerns, screening results, and diagnostic outcomes for young children evaluated across a statewide primary care network for early screening and diagnosis of autism spectrum disorder (ASD).
Study design
The Early Autism Evaluation Hub system was developed to increase developmental screening and improve access to timely ASD evaluations in local communities. In 2019, 858 children (ages 18-48 months; 40% diagnosed with ASD) received ASD evaluations across 12 Early Autism Evaluation Hubs. Data on primary care provider (PCP)- and caregiver-reported referral concerns, Modified Checklist for Autism in Toddlers, Revised with Follow-Up (MCHAT-R/F) and Ages and Stages Questionnaire, Third Edition (ASQ-3), and diagnostic outcome were collected.
Results
Among children evaluated, there was low concordance between PCP and caregiver referral concern. Although a positive MCHAT-R/F screen was associated with PCP but not caregiver-reported ASD referral concern, there was a significant linear relationship between MCHAT-R/F raw scores and both PCP and caregiver ASD referral concern. A different pattern of ASQ-3 delays was found to be associated with PCP-reported as compared with caregiver-reported ASD referral concern. Finally, PCP-reported ASD referral concern, positive MCHAT-R/F, and ASQ-3 Communication and Personal Social delays were associated with a significantly higher likelihood of subsequent ASD diagnosis.
Conclusions
Understanding how community PCPs use surveillance and screening data, the extent to which PCPs and caregivers have shared understanding and engage in collaborative decision-making about evaluation referral, and how these factors relate to diagnostic outcomes has the potential to impact educational efforts for both PCPs and caregivers of young children, as well as inform the development of more efficacious early identification approaches
Associations between sensory processing and electrophysiological and neurochemical measures in children with ASD: an EEG-MRS study
Background: Autism spectrum disorder (ASD) is associated with hyper- and/or hypo-sensitivity to sensory input. Spontaneous alpha power, which plays an important role in shaping responsivity to sensory information, is reduced across the lifespan in individuals with ASD. Furthermore, an excitatory/inhibitory imbalance has also been linked to sensory dysfunction in ASD and has been hypothesized to underlie atypical patterns of spontaneous brain activity. The present study examined whether resting-state alpha power differed in children with ASD as compared to TD children, and investigated the relationships between alpha levels, concentrations of excitatory and inhibitory neurotransmitters, and atypical sensory processing in ASD.
Methods: Participants included thirty-one children and adolescents with ASD and thirty-one age- and IQ-matched typically developing (TD) participants. Resting-state electroencephalography (EEG) was used to obtain measures of alpha power. A subset of participants (ASD = 16; TD = 16) also completed a magnetic resonance spectroscopy (MRS) protocol in order to measure concentrations of excitatory (glutamate + glutamine; Glx) and inhibitory (GABA) neurotransmitters.
Results: Children with ASD evidenced significantly decreased resting alpha power compared to their TD peers. MRS estimates of GABA and Glx did not differ between groups with the exception of Glx in the temporal-parietal junction. Inter-individual differences in alpha power within the ASD group were not associated with region-specific concentrations of GABA or Glx, nor were they associated with sensory processing differences. However, atypically decreased Glx was associated with increased sensory impairment in children with ASD.
Conclusions: Although we replicated prior reports of decreased alpha power in ASD, atypically reduced alpha was not related to neurochemical differences or sensory symptoms in ASD. Instead, reduced Glx in the temporal-parietal cortex was associated with greater hyper-sensitivity in ASD. Together, these findings may provide insight into the neural underpinnings of sensory processing differences present in ASD
A Statewide Tiered System for Screening and Diagnosis of Autism Spectrum Disorder
Although autism spectrum disorder (ASD) can be reliably detected in the second year of life, the average age of diagnosis is 4 to 5 years. Limitations in access to timely ASD diagnostic evaluations delay enrollment in interventions known to improve developmental outcomes. As such, developing and testing streamlined methods for ASD diagnosis is a public health and research priority. In this report, we describe the Early Autism Evaluation (EAE) Hub system, a statewide initiative for ASD screening and diagnosis in the primary care setting. Development of the EAE Hub system involved geographically targeted provision of developmental screening technical assistance to primary care, community outreach, and training primary care clinicians in ASD evaluation. At the EAE Hubs, a standard clinical pathway was implemented for evaluation of children, ages 18 to 48 months, at risk for ASD. From 2012 to 2018, 2076 children were evaluated (mean age: 30 months; median evaluation wait time: 62 days), and 33% of children received a diagnosis of ASD. Our findings suggest that developing a tiered system of developmental screening and early ASD evaluation is feasible in a geographic region facing health care access problems. Through targeted delivery of education, outreach, and intensive practice-based training, large numbers of young children at risk for ASD can be identified, referred, and evaluated in the local primary care setting. The EAE Hub model has potential for dissemination to other states facing similar neurodevelopmental health care system burdens. Implementation lessons learned and key system successes, challenges, and future directions are reviewed
Family-Centered Care Coordination in an Interdisciplinary Neurodevelopmental Evaluation Clinic: Outcomes From Care Coordinator and Caregiver Reports
Children with neurodevelopmental disabilities experience many unmet healthcare needs. Care coordination is one critical solution to addressing the substantial strain on families, local communities, and the larger healthcare system. The purpose of this study was to implement a care coordination program in an interdisciplinary pediatric neurodevelopmental evaluation clinic and examine care coordinator and caregiver outcomes. Following neurodevelopmental diagnosis, children were provided with either care coordination (CC) or care as usual (CAU). For those receiving CC, the care coordinator documented family goals and care coordination activities, outcomes, and time spent. Caregivers in both groups completed a survey measuring access to needed services and caregiver stress and empowerment following their child's evaluation (T1) and 4-6 months post-evaluation (T2). Care coordinator findings demonstrated that over 85% of family goals focused on understanding the child's diagnosis, getting needed interventions and educational support, and accessing healthcare financing programs. More than half of care coordination activities were spent on engaging and educating the family; similarly, the most time-consuming care coordination efforts were in helping families understand their child's diagnosis and meeting family's basic needs. For those children referred to needed services, 54% were enrolled in one or more service at T2. Caregivers in both the CC and CAU groups reported an increase in stress related to interactions with their child as well as increased empowerment from T1 to T2. Contrary to our hypotheses, there were no significant group-by-time interactions across caregiver-report measures. While these findings further our understanding of care coordination delivery, they diverge from previous evidence demonstrating care coordination efficacy. This study paves the way for future opportunities to evaluate what kinds of care coordination supports family need at varying times in their child's healthcare journey and how the outcomes important to all stakeholders are measured to reflect true evaluation of efficacy
INteractive Virtual Expert-Led Skills Training: A Multi-Modal Curriculum for Medical Trainees
Background: Internationally, pediatric depression and suicide are significant issues. Additionally, in the context of the COVID-19 pandemic, pediatric mental health needs are rising astronomically. In light of Child & Adolescent Psychiatrist (CAP) subspecialist shortages in the United States (US), there is an increasing call for primary care physicians in Family Medicine and Pediatrics to address an increasingly broad variety of patient needs. Here we report on the development and preliminary evaluation of medical student and resident perceptions on the “INteractive Virtual Expert-led Skills Training” (INVEST) medical education curriculum, a virtual synchronous CAP curriculum employing active learning strategies, including expert-led discussion and video modeling, and discussion designed to meet those priorities., Methods: In a standardized 60-min training format, our curriculum leverages audience response system polling, video modeling of key clinical skills, and interactive discussion with an expert subspecialist, over a virtual video conferencing platform. The primary educational strategy relies on use of video modeling to demonstrate best practice with CAP led group discussion to solidify and explain important concepts. Five waves of medical students and residents (N = 149) participated in the INVEST curriculum and completed pre- and post-training surveys regarding knowledge and comfort in the management of pediatric patients with depression and suicidality., Results: Trainee participants reported significant positive gains in perceived likelihood of encountering pediatric suicidality as well as knowledge/comfort with depression screening and suicidality assessment in a primary care setting. Across some competency areas, there was an effect of medical learner level. Learners at lower levels generally reported the highest benefit. Medical students reported significant increases in their comfort interpreting and discussing positive depression screens and evidenced the greatest relative benefit in comfort with discussing suicidality., Conclusion: To our knowledge, INVEST is the first fully virtual, multimodal curriculum led by expert CAP subspecialists. Our findings suggest that INVEST shows promise for equipping medical learners with baseline knowledge for caring for patients with pediatric depression and suicidality. This synchronous, virtually delivered curriculum allows for critical training delivered to diverse medical learners regardless of geographic location, a particular benefit during the current COVID-19 pandemic
Effects of eight neuropsychiatric copy number variants on human brain structure
Many copy number variants (CNVs) confer risk for the same range of neurodevelopmental symptoms and psychiatric conditions including autism and schizophrenia. Yet, to date neuroimaging studies have typically been carried out one mutation at a time, showing that CNVs have large effects on brain anatomy. Here, we aimed to characterize and quantify the distinct brain morphometry effects and latent dimensions across 8 neuropsychiatric CNVs. We analyzed T1-weighted MRI data from clinically and non-clinically ascertained CNV carriers (deletion/duplication) at the 1q21.1 (n = 39/28), 16p11.2 (n = 87/78), 22q11.2 (n = 75/30), and 15q11.2 (n = 72/76) loci as well as 1296 non-carriers (controls). Case-control contrasts of all examined genomic loci demonstrated effects on brain anatomy, with deletions and duplications showing mirror effects at the global and regional levels. Although CNVs mainly showed distinct brain patterns, principal component analysis (PCA) loaded subsets of CNVs on two latent brain dimensions, which explained 32 and 29% of the variance of the 8 Cohen’s d maps. The cingulate gyrus, insula, supplementary motor cortex, and cerebellum were identified by PCA and multi-view pattern learning as top regions contributing to latent dimension shared across subsets of CNVs. The large proportion of distinct CNV effects on brain morphology may explain the small neuroimaging effect sizes reported in polygenic psychiatric conditions. Nevertheless, latent gene brain morphology dimensions will help subgroup the rapidly expanding landscape of neuropsychiatric variants and dissect the heterogeneity of idiopathic conditions
Auditory Attentional Disengagement in Children with Autism Spectrum Disorder
Despite early differences in orienting to sounds, no study to date has investigated whether children with ASD demonstrate impairments in attentional disengagement in the auditory modality. Twenty-one nine- to fifteen year old children with ASD and 20 age- and IQ-matched TD children were presented with an auditory gap-overlap paradigm. Evidence of impaired disengagement in ASD was mixed. Differences in saccadic reaction time for overlap and gap conditions did not differ between groups. However, children with ASD did show increased no-shift trials in the overlap condition, as well as reduced disengagement efficiency compared to their TD peers. These results provide further support for disengagement impairments in ASD, and suggest that these deficits include disengaging from and shifting to unimodal auditory information