Investigating the autonomic nervous system response to anxiety in children with autism spectrum disorders

The Physiological and Clinical-Behavioral Effects of Heart Rate Variability Biofeedback in Adolescents with Autism: A Pilot Randomized Controlled Trial

Adolescents with autism present lower levels of cardiac vagal modulation. It was hypothesized that Heart Rate Variability Biofeedback (HRVB) increases cardiac vagal modulation in adolescents with autism, resulting in positive effects on physiological and psychosocial parameters. It was also hypothesized that home-based HRVB training is feasible. In a single-blind, randomized sham-controlled pilot trial, adolescents with autism performed supervised HRVB (n = 24) or sham training (n = 20). Subsequently, half of the adolescents received HRVB training at home, whereas the other subset did not practice. Physiological, cortisol and behavioral data were collected during stress-provoking assessments before and after each training period. Supervised HRVB resulted in a late increase in cardiac vagal modulation in adolescents with autism. Heart rate increased and cortisol decreased significantly immediately after supervised HRVB, but none of these effects remained after follow-up. Following supervised HRVB, no significant change in psychosocial functioning was found. Home-based HRVB was feasible, adolescents reported lower symptoms of stress, but a significant decrease in compliance rate was found. HRVB is feasible and effective in adolescents with autism given the late-emerging increases in cardiac vagal modulation and decrease in stress symptoms. Replicating this study with a larger sample and further exploration of the working mechanisms of HRVB are recommended. ClinicalTrials.gov , NCT04628715.

Experiences of siblings and parents of children with congenital heart disease and exploration of siblings' support needs

Research with siblings of children with congenital heart disease (CHD) is scarce, although more than one-third of them experience limitations on their quality of life. This interview study aims to explore the diagnosis-associated experience of German siblings of children with CHD, their interest in a potential intervention, and potential key topics and contextual conditions of such an intervention. Interviews with 10 siblings aged 10 to 21 and a respective parent were conducted from August to October 2021, resulting in 20 interviews. Negative experiences associated with CHD included concerns regarding hospitalization, health deterioration, and the death of the child with CHD, as well as burdens including reduced family activities, less parental attention and support, and extended family meals. Positive experiences included perceived positive consequences of CHD, such as strong family cohesion and empathy toward people with chronic illnesses. Furthermore, siblings experienced enhanced coping mechanisms, such as having conversations with friends and family about the high prevalence of CHD and successful treatment or using distractions such as entertainment or study. Siblings' reported interest in a future intervention included empathy, peer support, and studying medical information on CHD. These findings should be used for counseling and developing tailored interventions to support these siblings.

Machine learning-enabled detection of attention-deficit/hyperactivity disorder with multimodal physiological data: a case-control study

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD) is a multifaceted neurodevelopmental psychiatric condition that typically emerges during childhood but often persists into adulthood, significantly impacting individuals' functioning, relationships, productivity, and overall quality of life. However, the current diagnostic process exhibits limitations that can significantly affect its overall effectiveness. Notably, its face-to-face and time-consuming nature, coupled with the reliance on subjective recall of historical information and clinician subjectivity, stand out as key challenges. To address these limitations, objective measures such as neuropsychological evaluations, imaging techniques and physiological monitoring of the Autonomic Nervous System functioning, have been explored.

METHODS

The main aim of this study was to investigate whether physiological data (i.e., Electrodermal Activity, Heart Rate Variability, and Skin Temperature) can serve as meaningful indicators of ADHD, evaluating its utility in distinguishing adult ADHD patients. This observational, case-control study included a total of 76 adult participants (32 ADHD patients and 44 healthy controls) who underwent a series of Stroop tests, while their physiological data was passively collected using a multi-sensor wearable device. Univariate feature analysis was employed to identify the tests that triggered significant signal responses, while the Informative k-Nearest Neighbors (KNN) algorithm was used to filter out less informative data points. Finally, a machine-learning decision pipeline incorporating various classification algorithms, including Logistic Regression, KNN, Random Forests, and Support Vector Machines (SVM), was utilized for ADHD patient detection.

RESULTS

Results indicate that the SVM-based model yielded the optimal performance, achieving 81.6% accuracy, maintaining a balance between the experimental and control groups, with sensitivity and specificity of 81.4% and 81.9%, respectively. Additionally, integration of data from all physiological signals yielded the best results, suggesting that each modality captures unique aspects of ADHD.

CONCLUSIONS

This study underscores the potential of physiological signals as valuable diagnostic indicators of adult ADHD. For the first time, to the best of our knowledge, our findings demonstrate that multimodal physiological data collected via wearable devices can complement traditional diagnostic approaches. Further research is warranted to explore the clinical applications and long-term implications of utilizing physiological markers in ADHD diagnosis and management.

Functional Gastrointestinal Symptoms in Children with Autism and ADHD: Profiles of Hair and Salivary Cortisol, Serum Leptin Concentrations and Externalizing/Internalizing Problems

BACKGROUND

Functional Gastrointestinal Disorders (FGIDs) present a higher prevalence in individuals with Neurodevelopmental Disorders (NDDs). The Stress System and the Gut-Brain axis (GBA) may mediate these relations. We aimed to assess the prevalence and profile of FGIDs in a clinical sample of children with Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD) compared to typically developing children (TD) as well as to investigate possible relations between stress-related biomarkers and internalizing/externalizing problems in children with NDDS.

METHODS

In total, 120 children, aged between 4 and 12 years old, formed three groups (N = 40, each): ADHD, ASD and TD. Salivary cortisol, hair cortisol and serum leptin were measured.

RESULTS

The ASD group had more FGID problems than the TD group (p = 0.001). The ADHD and ASD groups had higher total internalizing/externalizing problems than the TD group (p < 0.0001, p < 0.0001, p = 0.005, respectively). Children with FGIDs showed more total, internalizing and externalizing problems compared to children without FGIDs (p < 0.0001, p < 0.0001, p = 0.041, respectively). The ADHD group showed lower AUCg values (p < 0.0001), while the hair cortisol was higher for the TD group (p < 0.0001).

CONCLUSION

In conclusion, children with NDDs had more FGID symptoms and present higher internalizing and externalizing problems. Children with ADHD and FGIDs had more internalizing problems compared to those without FGIDs. No differences in stress-related biomarkers were shown to differentiate children with NDDs with and without FGIDs. Future prospective studies including a greater number of children may elucidate the biological pathways linking these comorbidities.

Autonomic and hedonic response to affective touch in autism spectrum disorder

Interpersonal touch plays a crucial role in shaping relationships and encouraging social connections. Failure in processing tactile input or abnormal tactile sensitivity may hamper social behaviors and have severe consequences in individuals' relational lives. Autism Spectrum Disorder (ASD) is characterized by both sensory disruptions and social impairments, making affective touch an ideal meeting point for understanding these features in ASD individuals. By integrating behavioral and physiological measures, we investigated the effects of affective touch on adult individuals with ASD from both an implicit and explicit perspective. Specifically, at an implicit level, we investigated whether and how receiving an affective touch influenced participants' skin conductance tonic and phasic components. At the explicit level, we delved into the affective and unpleasant features of affective touch. Overall, we observed lower skin conductance level in ASD compared to TD subjects. Interestingly, the typically developing (TD) group showed an increased autonomic response for affective touch compared to a control touch, while ASD subjects' autonomic response did not differ between the two conditions. Furthermore, ASD participants provided higher ratings for both the affective and unpleasant components of the touch, compared to TD subjects. Our results reveal a noteworthy discrepancy in ASD population between the subjective experience, characterized by amplified hedonic but also unpleasant responses, and the physiological response, marked by a lack of autonomic activation related to affective touch. This insightful dissociation seems crucial for a deeper understanding of the distinctive challenges characterizing people with ASD and may have implications for diagnosis and therapeutic approaches.

Immediate effect of physical activity on the autonomic nervous system in individuals with autism spectrum disorders of different age groups: a randomised trial

Background

Autism spectrum disorder (ASD) is one of the most complex neurodevelopmental disorders. It affects almost all human physiological systems. Individuals with ASD often display dysregulation in their autonomic nervous system (ANS), which may elicit differing effects across age groups. Also, studying the ANS missed several important parameters related to ANS. Studying the ANS is crucial in developing adaptive behavioural strategies and maintaining communication abilities and social behaviours. Thus, this study compared the immediate effect of physical activity on the ANS in individuals with ASD in different age groups.

Methods

200 participants (106 males and 94 females) took part in a double-blinded randomised design. All participants were divided into four groups according to their age (4-7, 7-10, 10-13 and 14-18 years old). Participants performed a 60 min treadmill walk. The main outcome measurements were heart rate (HR), saturation of peripheral oxygen (SpO2), respiratory rate (RR) and end-tidal carbon dioxide (etCO2).

Results

Before the study, there were non-significant differences between groups in their physical characteristics (body mass index, Childhood Autism Rating Scale, physical activity level, both parents' existence, aerobic capacity and gender) (p>0.05). At baseline measurements, there were non-significant differences between all groups for all outcome measurements (p>0.05). Immediately after physical activity, there was significant difference between group 1 and other groups (p<0.05), while all other differences were non-significant (p>0.05). At the follow-up (after 15 min of rest), group 1 maintained significant differences with the other groups for all outcome measurements (p<0.05), while there were non-significant differences between the other three groups (p>0.05).

Conclusion

This study revealed that the SpO2 significantly decreased immediately after the physical activity, while HR, RR and etCO2 significantly increased immediately after physical activity in comparison to the baseline measurements. Contrary to other ANS parameters (SpO2, RR and etCO2), HR in early ages (4-7 years old) was higher after physical activity and remained elevated longer than other ages. The early ages (4-7 years old) take more time to return to the normal status of ANS parameters including SpO2, HR, RR and etCO2.

Trial registration number

NCT05725733.

Behavioral and physiological differences during an emotion-evoking task in children at increased likelihood for autism spectrum disorder

Literature examining emotional regulation in infants with autism spectrum disorder (ASD) has focused on parent report. We examined behavioral and physiological responses during an emotion-evoking task designed to elicit emotional states in infants. Infants at an increased likelihood for ASD (IL; have an older sibling with ASD; 96 not classified; 29 classified with ASD at age two) and low likelihood (LL; no family history of ASD; n = 61) completed the task at 6, 12, and 18 months. The main findings were (1) the IL-ASD group displayed higher levels of negative affect during toy removal and negative tasks compared to the IL non-ASD and LL groups, respectively, (2) the IL-ASD group spent more time looking at the baseline task compared to the other two groups, and (3) the IL-ASD group showed a greater increase in heart rate from baseline during the toy removal and negative tasks compared to the LL group. These results suggest that IL children who are classified as ASD at 24 months show differences in affect, gaze, and heart rate during an emotion-evoking task, with potential implications for understanding mechanisms related to emerging ASD.

Comparative analysis of electrodermal activity metrics and their association with child behavior in autism spectrum disorder

Researchers are increasingly utilizing physiological data like electrodermal activity (EDA) to understand how stress "gets under the skin." Results of EDA studies in autistic children are mixed, with some suggesting autistic hyperarousal, others finding hypoarousal, and yet others detecting no difference compared to non-autistics. Some of this variability likely stems from the different techniques used to assess EDA. Therefore, the purpose of this study is to investigate and compare commonly used metrics of EDA (frequency of peaks, average amplitude of peaks, and standard deviation of skin conductance level) using two data processing programs (NeuroKit2 and Ledalab) and their link to observed child behavior. EDA data were collected using Empatica E4 wristbands from 60 autistic children and adolescents (5-18 years old) during a 7-min play interaction with their primary caregiver. The play interaction was coded for a range of child behaviors including mood, social responsiveness, dysregulation, and cooperation. Results indicate a strong correlation between NeuroKit2 and Ledalab and a weak correlation between metrics within each program. Furthermore, the frequency of peaks was associated with more positive child social behaviors, and the magnitude of peaks was associated with less adaptive child behaviors. Recommendations for replication and the need for generalizability of this research are given.

Development and Parasympathetic Regulation in Male and Female Adolescents with Autism Spectrum Disorder: A Two-Timepoint Longitudinal Study

Prolonged dysregulation of the autonomic nervous system (ANS) may increase propensity for physical or psychiatric illness. The current study examined differences in respiratory sinus arrhythmia (RSA) regulation in 215 adolescents with or without autism spectrum disorder (ASD) at Time 1 (T1; 10-13 years old) and 1 year later (Time 2; T2). Linear mixed effects models demonstrated lower RSA regulation in ASD, and a small interaction effect, showing blunted change in RSA from T1 to T2. Developmental differences in RSA regulation were particularly notable in females with ASD and those taking psychotropic medications. Results expand previous findings of reduced parasympathetic regulation in ASD by revealing a blunted developmental slope, indicating diagnostic differences may persist or worsen over time, particularly in females.

Patterns of Food Selectivity among Children with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by food selectivity in a significant portion of the population. The nature of this selectivity remains unclear, with hypotheses suggesting associations with sensory disorders or stereotypical and repetitive patterns of activity and interests. This study aimed to determine the prevalence and nature of food selectivity traits in individuals with ASD compared with the neurotypical population. This study involved 219 participants, with 115 diagnosed with autism and 92 without. Twelve children undergoing diagnosis were excluded from the analyses. The findings revealed that food selectivity traits are more common in individuals with ASD, with differences in preferences mainly involving structure, color, taste, and serving method. Children with ASD had more food selectivity traits than those without, and the intake of certain food characteristics could be altered as they grow. Selectivity occurred for both sensory and stereotypical reasons, but stereotypical features significantly differentiated neurotypical individuals from those with ASD.

Motor Skills, Heart Rate Variability, and Arterial Stiffness in Children with Autism Spectrum Disorder

The prevalence of autism spectrum disorder (ASD) among children has been recently increasing. The severity of symptoms greatly varies between individuals with ASD, ranging from relatively mild to extremely severe. It is important to have a clearer understanding of the possible adverse consequences resulting from this disorder, such as delayed motor development, autonomic dysregulation, and arterial stiffness. Thus, the objective of this study was to investigate differences in motor skills, heart rate variability (HRV), and arterial stiffness between children with ASD and typically developing children. In this study, the school-aged children with mild symptoms of ASD (n = 17, 11.1 ± 1.0 years old) and typically developing peers (n = 15, 11.0 ± 0.5 years old) were recruited. Motor skills, HRV, and arterial stiffness were measured in these two groups. Motor skills were evaluated by the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition. Moreover, HRV was measured through a short-term recording using the Polar heart rate monitor, and arterial stiffness was assessed by non-invasive computerized oscillometry. Compared with the typically developing group, children with ASD displayed significant deficits in some areas of motor skills, including manual coordination, strength and agility, and total motor composite. Moreover, children with ASD exhibited significantly reduced HRV, including time- and frequency-domain measures. However, the results did not demonstrate any statistically significant differences in arterial stiffness between the groups. Our findings demonstrated the presence of motor skill deficits and autonomic dysregulation in children with ASD.

Autism spectrum disorders in adults and the autonomic nervous system: Heart rate variability markers in the diagnostic procedure

The diagnostic assessment of autism spectrum disorders (ASD) in adults is a challenging and time-consuming procedure. In order to address the lack of specialised health-care professionals and improve the waiting time, we aimed to identify specific electrocardiogram (ECG) derived Heart Rate Variability (HRV) parameters that could be used for diagnostic purposes. 152 patients were diagnosed based on a standardised clinical procedure and assigned to one of three groups: ASD (n = 56), any other psychiatric disorder (OD) (n = 72), and patients with no diagnosis (ND) (n = 24). Groups were compared using ANOVA. Discriminative power of biological parameters and the clinical assessment were compared using receiver operating characteristic curves (ROCs). Patients with ASD showed reduced parasympathetic and increased sympathetic activity compared to ND. The accuracy determined by the area under the curve (AUC) of the biological parameters for discrimination between ASD vs. pooled OD/ND was 0.736 (95% CI = 0.652-0.820), compared to .856 (95% CI = 0.795-0.917) for the extensive clinical assessment. Our results confirmed the dysregulation of the autonomic nervous system in ASD with reduced parasympathetic and increased sympathetic activity as compared to ND. The discriminative power of biological markers including HRV was considerable and could supplement less sophisticated clinical assessments.

Heart rate monitoring to detect acute pain in non-verbal patients: a study protocol for a randomized controlled clinical trial

BACKGROUND

Autism entails reduced communicative abilities. Approximately 30% of individuals with autism have intellectual disability (ID). Some people with autism and ID are virtually non-communicative and unable to notify their caregivers when they are in pain. In a pilot study, we showed that heart rate (HR) monitoring may identify painful situations in this patient group, as HR increases in acutely painful situations.

OBJECTIVES

This study aims to generate knowledge to reduce the number of painful episodes in non-communicative patients' everyday lives. We will 1) assess the effectiveness of HR as a tool for identifying potentially painful care procedures, 2) test the effect of HR-informed changes in potentially painful care procedures on biomarkers of pain, and 3) assess how six weeks of communication through HR affects the quality of communication between patient and caregiver.

METHODS

We will recruit 38 non-communicative patients with autism and ID residing in care homes.

ASSESSMENTS

HR is measured continuously to identify acutely painful situations. HR variability and pain-related cytokines (MCP-1, IL-1RA, IL-8, TGFβ1, and IL-17) are collected as measures of long-term pain. Caregivers will be asked to what degree they observe pain in their patients and how well they believe they understand their patient's expressions of emotion and pain. Pre-intervention: HR is measured 8 h/day over 2 weeks to identify potentially painful situations across four settings: physiotherapy, cast use, lifting, and personal hygiene.

INTERVENTION

Changes in procedures for identified painful situations are in the form of changes in 1) physiotherapy techniques, 2) preparations for putting on casts, 3) lifting techniques or 4) personal hygiene procedures.

DESIGN

Nineteen patients will start intervention in week 3 while 19 patients will continue data collection for another 2 weeks before procedure changes are introduced. This is done to distinguish between specific effects of changes in procedures and non-specific effects, such as caregivers increased attention.

DISCUSSION

This study will advance the field of wearable physiological sensor use in patient care.

TRIAL REGISTRATION

Registered prospectively at ClinicalTrials.gov (NCT05738278).

Neurophysiological Correlates of Sensory-Based Phenotypes in ASD

Children with autism spectrum disorder frequently present with atypical behavioral responses to sensory stimuli, as well as differences in autonomic nervous system (ANS) and neuroendocrine activity. However, no one consistent pattern appears to explain these differences within this heterogeneous population. To conceptualize more homogenous ASD subgroups, sensory-based subtypes have been explored. One subtyping mechanism groups children by sensory responsivity pattern in addition to sensory domain. Differences in nervous system responsivity to sensory input within this sensory-based subtyping scheme have not yet been investigated. This exploratory study used ANS indices (respiratory sinus arrhythmia [RSA], skin conductance level) and neuroendocrine (salivary cortisol) response to examine patterns differentiating these subtypes. Significant differences in RSA were found during baseline, and during tactile, tone and movement stimuli (p < 0.05). Subtype membership was predicted by RSA changes during auditory stimulation and recovery periods (p < 0.05). Results confirm that children with an adaptive sensory responsivity subtype differ from those children with sensory processing dysfunction, however, physiological variables did not distinguish between children with different patterns of sensory processing dysfunction.

Simulating developmental diversity: Impact of neural stochasticity on atypical flexibility and hierarchy

Introduction

Investigating the pathological mechanisms of developmental disorders is a challenge because the symptoms are a result of complex and dynamic factors such as neural networks, cognitive behavior, environment, and developmental learning. Recently, computational methods have started to provide a unified framework for understanding developmental disorders, enabling us to describe the interactions among those multiple factors underlying symptoms. However, this approach is still limited because most studies to date have focused on cross-sectional task performance and lacked the perspectives of developmental learning. Here, we proposed a new research method for understanding the mechanisms of the acquisition and its failures in hierarchical Bayesian representations using a state-of-the-art computational model, referred to as in silico neurodevelopment framework for atypical representation learning.

Methods

Simple simulation experiments were conducted using the proposed framework to examine whether manipulating the neural stochasticity and noise levels in external environments during the learning process can lead to the altered acquisition of hierarchical Bayesian representation and reduced flexibility.

Results

Networks with normal neural stochasticity acquired hierarchical representations that reflected the underlying probabilistic structures in the environment, including higher-order representation, and exhibited good behavioral and cognitive flexibility. When the neural stochasticity was high during learning, top-down generation using higher-order representation became atypical, although the flexibility did not differ from that of the normal stochasticity settings. However, when the neural stochasticity was low in the learning process, the networks demonstrated reduced flexibility and altered hierarchical representation. Notably, this altered acquisition of higher-order representation and flexibility was ameliorated by increasing the level of noises in external stimuli.

Discussion

These results demonstrated that the proposed method assists in modeling developmental disorders by bridging between multiple factors, such as the inherent characteristics of neural dynamics, acquisitions of hierarchical representation, flexible behavior, and external environment.

Chronic Pain-Associated Cardiovascular Disease: The Role of Sympathetic Nerve Activity

Chronic pain affects many people world-wide, and this number is continuously increasing. There is a clear link between chronic pain and the development of cardiovascular disease through activation of the sympathetic nervous system. The purpose of this review is to provide evidence from the literature that highlights the direct relationship between sympathetic nervous system dysfunction and chronic pain. We hypothesize that maladaptive changes within a common neural network regulating the sympathetic nervous system and pain perception contribute to sympathetic overactivation and cardiovascular disease in the setting of chronic pain. We review clinical evidence and highlight the basic neurocircuitry linking the sympathetic and nociceptive networks and the overlap between the neural networks controlling the two.

Atypical Response to Affective Touch in Children with Autism: Multi-Parametric Exploration of the Autonomic System

This study aimed at evaluating the autonomic response to pleasant affective touch in children with Autism Spectrum Disorders (ASD) and age-matched typically developing (TD) peers, thanks to multiple autonomic nervous system (ANS) parameters and by contrasting CT (C-tactile fibers) high- vs. low-density territory stimulations. We measured pupil diameter, skin conductance, and heart rate during gentle stroking of two skin territories (CT high- and low-density, respectively, forearm and palm of the hand) in thirty 6-12-year-old TD children and twenty ASD children. TD children showed an increase in pupil diameter and skin conductance associated with a heart rate deceleration in response to tactile stimulations at the two locations. Only the pupil was influenced by the stimulated location, with a later dilation peak following CT low-density territory stimulation. Globally, ASD children exhibited reduced autonomic responses, as well as different ANS baseline values compared to TD children. These atypical ANS responses to pleasant touch in ASD children were not specific to CT-fiber stimulation. Overall, these results point towards both basal autonomic dysregulation and lower tactile autonomic evoked responses in ASD, possibly reflecting lower arousal and related to social disengagement.

Higher scores on autonomic symptom scales in pediatric patients with neurodevelopmental disorders of known genetic etiology

INTRODUCTION

Features of underlying autonomic dysfunction, including sleep disturbances, gastrointestinal problems, and atypical heart rate, have been reported in neurodevelopmental conditions, including autism spectrum disorder (ASD). The current cross-sectional, between-groups study aimed to quantify symptoms of autonomic dysfunction in a neurodevelopmental pediatric cohort characterized by clinical diagnoses as well as genetic etiology.

METHOD

The Pediatric Autonomic Symptom Scales (PASS) questionnaire was used to assess autonomic features across a group of patients with clinical neurodevelopmental diagnoses (NPD; N = 90) and genetic etiologies. Patients were subdivided based on either having a clinical ASD diagnosis (NPD-ASD; n = 37) or other non-ASD neurodevelopmental diagnoses, such as intellectual disability without ASD, speech and language disorders, and/or attention deficit hyperactivity disorder (NPD-OTHER; n = 53). Analyses focused on characterizing differences between the NPD group compared to previously published reference samples, as well as differences between the two NPD subgroups (NPD-ASD and NPD-OTHER).

RESULTS

Our results indicate higher PASS scores in our NPD cohort relative to children with and without ASD from a previously published cohort. However, we did not identify significant group differences between our NPD-ASD and NPD-OTHER subgroups. Furthermore, we find a significant relationship between quantitative ASD traits and symptoms of autonomic function.

CONCLUSION

This work demonstrates the utility of capturing quantitative estimates of autonomic trait dimensions that may be significantly linked with psychosocial impairments and other core clinical features of ASD.

A Randomised Crossover Trial of Behaviour Guidance Techniques on Children with Special Health Care Needs during Dental Treatment: The Physiological Variations

Passive immobilisation is regarded as able to potentially cause physical distress and intense anxiety manifestations. The study aims to investigate the physiological variations of children with special health care needs while using a Papoose board and a combination of basic behaviour guidance during dental treatment. This is a randomised crossover trial involving 90 children with special health care needs receiving standard dental care with two methods of behaviour guidance sequentially. Exposure A is a combination of tell-show-do, distraction, and positive reinforcement, while exposure B is passive immobilisation with a Papoose board. The subject child’s blood pressure, heart rate, and oxygen saturation level were measured at four different times during dental treatment. In total, 74 children’s physiological data were successfully collected with a mean age of 9.85 years (SD = 2.71). Further, 64.9% of the children were diagnosed with autism spectrum disorder, 12.2% with attention deficit hyperactivity disorder, 9.5% with intellectual disability, 8.1% with Down syndrome, 2.2% with global developmental delay, and 1.1% with dyslexia and cerebral palsy, respectively. The measurement of children’s blood pressure, heart rate, and oxygen saturation level with the application of a Papoose board or a combination of the basic behaviour guidance revealed no significant changes (p > 0.05). The use of a Papoose board is safe and has no discernible influence on the child’s physiological responses.

Diagnostic and Physical Effects in Parasympathetic Response to Social Evaluation in Youth With and Without Autism Spectrum Disorder

Individuals with autism spectrum disorder (ASD) may demonstrate atypical autonomic (ANS) responses; however, research remains inconsistent. This study examined parasympathetic response during social evaluation in 241 youth (10-13 years) with ASD (n = 138) or typical development (TD; n = 103). Diagnosis, age, pubertal development, and body mass index (BMI) were hypothesized to be associated with ANS function. Linear mixed effects models demonstrated lower RSA in ASD relative to TD in a base model with no covariates. However, when accounting for differences in BMI, there was no evidence of atypical parasympathetic regulation in youth with ASD. As lower parasympathetic regulation may increase susceptibility for a number of conditions, it will be important to elucidate the link between BMI and the ANS, especially in ASD.

Examining the impact of social stressor stimuli in eliciting physiological reactivity in children and adolescents with autism spectrum disorder: a systematic review and meta-analysis protocol

INTRODUCTION

Stress is not experienced the same by everyone. Some individuals, such as individuals with autism spectrum disorder (ASD), are at risk of heightened sensitivity to stress responses. ASD is a neurodevelopmental disorder commonly characterised by deficits in social communication and social interaction. Among different stressor stimuli, social stressors are particularly worth our attention due to the social and communication challenges inherent in ASD. This study aims to systematically evaluate different social stressor stimuli in eliciting physiological reactivity in ASD, focusing on the children and adolescent population.

METHODS AND ANALYSIS

We designed a study protocol for this study and submitted it to PROSPERO for systematic review registration. Any studies with children and adolescents with ASD between the ages of 0 and 18 in clinical and community settings will be included. All types of social stressor interventions will be included. The outcome of interest will include studies with physiological activity of the participants being measured, for example, measures related to autonomic functioning, electrodermal functioning and cortisol level. The primary literature sources will be across four electronic databases: MEDLINE, Embase, PsycInfo and CINAHL in August 2021. The second source of literature will be across grey literature, including ProQuest Dissertations & Theses Global and across clinical trial registries in August 2021. Hand searching of references will be performed on the reference lists of all included studies. Two volunteers pursuing postgraduate-level studies will independently search and screen potential studies for eligibility. Finally, all references considered by hand searching will be reviewed by two researchers. The methodological quality of the research will be assessed by adopting the quality assessment used by a previous study. The assessment consists of four primary categories: descriptive validity, internal validity, external validity and statistical conclusion validity.

ETHICS AND DISSEMINATION

No ethical approval is required for this study. Results will be disseminated through conferences and publications in relevant peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42021244039.

Indices of Heart Rate Variability and Performance During a Response-Conflict Task Are Differently Associated With ADHD and Autism

We investigated autonomic arousal, attention and response conflict, in ADHD and autism. Heart rate variability (HRV), and behavioral/electrophysiological indices of performance, were recorded during a task with low and high levels of response conflict in 78 children/adolescents (7-15 years old) with ADHD, autism, comorbid ADHD+autism, or neurotypical. ANOVA models were used to investigate effects of ADHD and autism, while a mediation model was tested to clarify the relationship between ADHD and slower performance. Slower and less accurate performance characterized ADHD and autism; however, atypical electrophysiological indices differently characterized these conditions. The relationship between ADHD and slower task performance was mediated by reduced HRV in response to the cue stimulus. Autonomic hypo-arousal and difficulties in mobilizing energetic resources in response to sensory information (associated with ADHD), and atypical electrophysiological indices of information processing (associated with autism), might negatively affect cognitive performance in those with ADHD+autism.

Stress System Activation in Children and Adolescents With Autism Spectrum Disorder

The mission of the human stress system is the maintenance of homeostasis in the presence of real or perceived, acute or chronic stressors. The hypothalamic–pituitary–adrenal (HPA) axis and the autonomic nervous system (ANS) are the stress system-related neuroendocrine pathways. There is abundant evidence that children and adolescents with autism spectrum disorder (ASD) may exhibit atypical function within the HPA axis and the ANS both at the resting state and during the presence of social and/or non-social stressors. The aim of this review is to provide an up-to-date summary of the findings regarding stress system alterations in children and adolescents with ASD. We focus on the variations of stress hormones circadian rhythms, specifically cortisol and alpha-amylase (i.e., a surrogate index of epinephrine/norepinephrine secretion), and on the alterations of stress system responsivity to different stressors. Also, we present imaging and immunological findings that have been associated with stress system dysregulation in children and adolescents with ASD. Finally, we review the pivotal role of HPA axis-ANS coordination, the developmental trajectory of the stress system in ASD, and the possible role of early life stress in the dysregulation of the stress system demonstrated in children and adolescents with ASD. This synthesis will hopefully provide researchers with a foundation for an integrated approach to future research into stress system variations in children and adolescents with ASD.

Functional links between thermoregulation and sleep in children with neurodevelopmental and chronic health conditions

The bi-directional relationship between sleep and wake is recognized as important for all children. It is particularly consequential for children who have neurodevelopmental disorders (NDDs) or health conditions which challenge their sleep and biological rhythms, and their ability to maintain rhythms of participation in everyday activities. There are many studies which report the diverse reasons for disruption to sleep in these populations. Predominantly, there is focus on respiratory, pharmaceutical, and behavioral approaches to management. There is, however, little exploration and explanation of the important effects of body thermoregulation on children's sleep-wake patterns, and associated behaviors. Circadian patterns of sleep-wake are dependent on patterns of body temperature change, large enough to induce sleep preparedness but remaining within a range to avoid sleep disturbances when active thermoregulatory responses against heat or cold are elicited (to maintain thermoneutrality). Additionally, the subjective notion of thermal comfort (which coincides with the objective concept of thermoneutrality) is of interest as part of general comfort and associated behavioral responses for sleep onset and maintenance. Children's thermoregulation and thermal comfort are affected by diverse biological functions, as well as their participation in everyday activities, within their everyday environments. Hence, the aforementioned populations are additionally vulnerable to disruption of their thermoregulatory system and their capacity for balance of sleep and wakefulness. The purpose of this paper is to present hitherto overlooked information, for consideration by researchers and clinicians toward determining assessment and intervention approaches to support children's thermoregulation functions and promote their subjective thermal comfort, for improved regulation of their sleep and wake functions.

Transdermal Electrical Neuromodulation for Anxiety and Sleep Problems in High-Functioning Autism Spectrum Disorder: Feasibility and Preliminary Findings

BACKGROUND

Autism spectrum disorder (ASD) is associated with anxiety and sleep problems. We investigated transdermal electrical neuromodulation (TEN) of the cervical nerves in the neck as a safe, effective, comfortable and non-pharmacological therapy for decreasing anxiety and enhancing sleep quality in ASD.

METHODS

In this blinded, sham-controlled study, seven adolescents and young adults with high-functioning ASD underwent five consecutive treatment days, one day of the sham followed by four days of subthreshold TEN for 20 min. Anxiety-provoking cognitive tasks were performed after the sham/TEN. Measures of autonomic nervous system activity, including saliva α-amylase and cortisol, electrodermal activity, and heart rate variability, were collected from six participants.

RESULTS

Self-rated and caretaker-rated measures of anxiety were significantly improved with TEN treatment as compared to the sham, with effect sizes ranging from medium to large depending on the rating scale. Sleep scores from caretaker questionnaires also improved, but not significantly. Performance on two of the three anxiety-provoking cognitive tasks and heart rate variability significantly improved with TEN stimulation as compared to the sham. Four of the seven (57%) participants were responders, defined as a ≥ 30% improvement in self-reported anxiety. Salivary α-amylase decreased with more TEN sessions and decreased from the beginning to the end of the session on TEN days for responders. TEN was well-tolerated without significant adverse events.

CONCLUSIONS

This study provides preliminary evidence that TEN is well-tolerated in individuals with ASD and can improve anxiety.

Physiological reactivity in children with high callous-unemotional and autistic traits: investigating unique and interactive effects

Empathy deficits are a hallmark sign of both callous-unemotional (CU) and autistic traits. Despite these similarities, prior work did not investigate how these traits relate to physiological reactivity (heart rate and skin conductance) in response to emotional or empathy-eliciting stimuli. Understanding the physiological mechanisms associated with emotional processing deficits among individuals with autistic or CU traits is a critical step for improving both assessment and interventions. The current study was designed to investigate the unique and interactive contributions of CU and autistic traits in predicting physiological reactivity. Heart rate (HR) and skin conductance (SC) activity in response to sad, fearful and happy emotional videos were collected form young children. Participants for the current study (n = 163; M_age = 7.30, SD= 1.42; 44.2% girls) were recruited from a larger community sample of 1652 children and were selected based on their levels of empathy. Regression analysis revealed that boys, but not girls, with high levels of CU traits exhibited low SC reactivity during sad and fearful stimuli. No significant associations were revealed for autistic traits. Finally, an interesting interaction effect suggested that CU traits were associated with stronger HR reactivity to fear stimuli only when autistic traits were low. The identified differences in physiological reactivity can inform etiological hypothesis by providing evidence for the underlying physiological mechanisms related to emotional processing among children high in CU traits but not in autistic traits.

Heart Rate Variability in Children and Adolescents with Autism, ADHD and Co-occurring Autism and ADHD, During Passive and Active Experimental Conditions

Despite overlaps in clinical symptomatology, autism and ADHD may be associated with opposite autonomic arousal profiles which might partly explain altered cognitive and global functioning. We investigated autonomic arousal in 106 children/adolescents with autism, ADHD, co-occurring autism/ADHD, and neurotypical controls. Heart rate variability was recorded during resting-state, a 'passive' auditory oddball task and an 'active' response conflict task. Autistic children showed hyper-arousal during the active task, while those with ADHD showed hypo-arousal during resting-state and the passive task. Irrespective of diagnosis, children characterised by hyper-arousal showed more severe autistic symptomatology, increased anxiety and reduced global functioning than those displaying hypo-arousal, suggesting the importance of considering individual autonomic arousal profiles for differential diagnosis of autism/ADHD and when developing personalised interventions.

Evaluating the potential of respiratory-sinus-arrhythmia biofeedback for reducing physiological stress in adolescents with autism: study protocol for a randomized controlled trial

Background

Prior evidence points towards lower cardiac vagal modulation in individuals with autism spectrum disorder (ASD) as compared to control groups. A cross-sectional phase in this study will gather more evidence concerning this topic. A longitudinal phase will explore the efficacy of a biofeedback intervention based on respiratory sinus arrhythmia (RSA) in adolescents with ASD. Finally, a feasibility study will focus on a non-supervised RSA biofeedback intervention in this population.

Methods

The cross-sectional phase includes the comparison of adolescents with ASD (n=38) and age- and gender-matched typically developing peers. A standardized assessment will be used which contains physiological, cortisol, and behavioral measurements. The longitudinal phase contains a randomized, single-blinded, and sham-controlled design to determine the efficacy of supervised RSA biofeedback in adolescents with ASD (n=128). A follow-up phase of 5 weeks is included to evaluate the presence of retention effects. During the latter, a feasibility study will focus on a non-supervised intervention (n=64). Assessments as described previously are scheduled after the intervention and the follow-up phase.

Discussion

First, more conclusive evidence will be provided for the presence of lower cardiac vagal modulation in adolescents with ASD as well as the association between these lower values and physiological and behavioral indices. Second, the supervised intervention in adolescents with ASD is hypothesized to upregulate this cardiac vagal modulation and positively change behavioral and physiological parameters. Third, evidence regarding the feasibility and acceptability of a non-supervised intervention may open novel avenues for home-based interventions in this population.

Trial registration

ClinicalTrials.govNCT04628715. Registered on 13 November 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05709-4.

Associations between physiological and neural measures of sensory reactivity in youth with autism

BACKGROUND

Individuals with Autism Spectrum Disorder (ASD) commonly show sensory over-responsivity (SOR), an impairing condition related to over-reactive brain and behavioral responses to aversive stimuli. While individuals with ASD often show atypically high physiological arousal, it is unclear how this relates to sensory reactivity. We therefore investigated how physiological arousal relates to brain and behavioral indices of SOR, to inform understanding of the biological mechanisms underlying SOR and to determine whether physiological measures are associated with SOR-related brain responses.

METHODS

Youth aged 8-18 (49 ASD; 30 age- and performance-IQ-matched typically developing (TD)) experienced mildly aversive tactile and auditory stimuli first during functional magnetic resonance imaging (N = 41 ASD, 26 TD) and then during skin conductance (SCR) (N = 48 ASD, 28 TD) and heart rate (HR) measurements (N = 48 ASD, 30 TD). Parents reported on their children's SOR severity.

RESULTS

Autism Spectrum Disorder youth overall displayed greater SCR to aversive sensory stimulation than TD youth and greater baseline HR. Within ASD, higher SOR was associated with higher mean HR across all stimuli after controlling for baseline HR. Furthermore, the ASD group overall, and the ASD-high-SOR group in particular, showed reduced HR deceleration/greater acceleration to sensory stimulation compared to the TD group. Both SCR and HR were associated with brain responses to sensory stimulation in regions previously associated with SOR and sensory regulation.

CONCLUSIONS

Autism Spectrum Disorder youth displayed heightened physiological arousal to mildly aversive sensory stimulation, with HR responses in particular showing associations with brain and behavioral measures of SOR. These results have implications for using psychophysiological measures to assess SOR, particularly in individuals with ASD who cannot undergo MRI.

Person-Oriented Research Ethics to Address the Needs of Participants on the Autism Spectrum

Research ethics scholarship often attends to vulnerability. People with autism may be vulnerable in research, but are also vulnerable to unjust exclusion from participation. Addressing the needs of participants with autism can facilitate inclusion and honor the bioethics principle of respect for persons while accounting for risk and vulnerability. Drawing from a review of the literature and informed by a moral deliberation process involving a task force of stakeholders (including autistic people and parents of autistic people), we use the model of person-oriented research ethics to identify several practical strategies researchers can use to address these needs and foster inclusion. Strategies include using multiple means of communication, addressing the sensory environment, preparing participants in advance, and accounting for social context. These practical strategies are not just methodological or design choices; they are inherently related to ethical issues. Method and design choices fulfill ethical aspirations by facilitating inclusion, reducing discomfort, and focusing on individuals.

Sleep Dysregulation and Daytime Electrodermal Patterns in Children With Autism: A Descriptive Study

Sleep deficiency influences emotion and behavior regulation but the mechanisms of influence are poorly understood. Emotion, behavioral, and sleep theories highlight differences in autonomic function as a potential pathway of influence and research in typical populations draw links between sleep deficiency and autonomic dysregulation (e.g., elevated reactivity within the sympathetic nervous system). In populations at elevated risk for sleep deficiency/problems (i.e., individuals with autism), greater variability in sleep and autonomic/arousal profiles may be particularly informative. Using electrodermal activity (EDA) as an indicator of sympathetic nervous system activation, this descriptive pilot study aimed to document daytime EDA patterns in children with autism and to explore their relations with sleep dysregulation/deficiency. EDA and sleep were measured using ankle and wrist worn sensors in 13 children (Mean_age 6.11 years). EDA indices included nonspecific skin conductance responses (NSSCR) and tonic skin conductance levels (SCL). Descriptively, children in the dysregulated sleep group had fewer NSSCRs and lower SCL in the afternoon. This blunted physiological arousal profile/pattern is consistent with previous research, but this is the first study to explore how sleep may be linked. Notably, this pattern may not reflect sleep but an overall dysregulation profile which in this sample included: dysregulated sleep, a blunted afternoon arousal profile, and elevated ASD symptom severity. Replication with larger, more diverse samples is needed to disentangle the complex relations among sleep, arousal, and ASD behavioral features. However, this study represents an important first step in documenting extended daytime arousal patterns.

Children With Autism Exhibit More Individualized Responses to Live Animation Biofeedback Than Do Typically Developing Children

Children with autism have displayed imbalances in responding to feedback and feedforward learning information and they have shown difficulty imitating movements. Previous research has focused on motor learning and coordination problems for these children, but little is known about their motoric responses to visual live animation feedback. Thus, we compared motor output responses to live animation biofeedback training in both 15 children with autism and 15 age- and sex-matched typically developing children (age range: 8-17 years). We collected kinematic data via Inertial Measurement Unit devices while participants performed a series of body weight squats at a pre-test, during live animation biofeedback training, and at post-test. Dependent t-tests (α = 0.05), were used to test for statistical significance between pre- and post-test values within groups, and repeated measures analyses of variance (α = 0.05) were used to test for differences among the training blocks, within each group. The Model Statistic technique (α = 0.05) was used to test for pre- and post-test differences on a single-subject level for every participant. Grouped data revealed little to no significant findings in the children with autism, as these participants showed highly individualized responses. However, typically developing children, when grouped, exhibited significant differences in their left hip position (p = 0.03) and ascent velocity (p = 0.004). Single-subject analyses showed more individualistic live animation responses of children with autism than typically developing children on every variable of interest except descent velocity. Thus, to teach children with autism new movements in optimal fashion, it is particularly important to understand their individualistic motor learning characteristics.

Exploring Social Biomarkers in High-Functioning Adults with Autism and Asperger's Versus Healthy Controls: A Cross-Sectional Analysis

Biomarkers for autism spectrum disorder (ASD) are lacking but would facilitate drug development for the core deficits of the disorder. We evaluated markers proposed for characterization of differences in social communication and interaction in adults with ASD versus healthy controls (HC) for utility as biomarkers. Data pooled from an observational study and baseline data from a placebo-controlled study were analyzed. Between-group differences were observed in eye-tracking tasks for activity monitoring, biomotion, human activity preference, composite score (p = 0.0001-0.037) and pupillometry (various tasks, p = 0.017-0.05). Impaired olfaction was more common in the ASD sample versus HC (p = 0.018). Our preliminary results suggest the potential use for stratification and response sub-analyses outcome-prediction of specific eye-tracking tasks, pupillometry and olfaction tests in ASD trials.

Salivary cortisol and alpha-amylase daily profiles and stress responses to an academic performance test and a moral cognition task in children with neurodevelopmental disorders

There is evidence that children with neurodevelopmental disorders may exhibit atypical responses to stress and alterations in concentrations and diurnal secretion of stress hormones. We assessed diurnal profiles and stress responses of salivary cortisol and alpha-amylase (sAA) in children with attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and specific learning disorder (SLD) compared to typically developing children (TD). A total of 157 children of both sexes, aged between 6 and 12 years old, took part in the study distributed into four groups: ADHD (N = 34), ASD (N = 56), SLD (N = 43) and TD (N = 24). Salivary samples were collected at three time points during a day, as well as before and 5 min after an academic performance test and a moral cognition task. ADHD children had lower evening and diurnal sAA levels, adjusted for age. Also, ASD children showed lower diurnal sAA secretion, adjusted for age. The mean percentage change for salivary cortisol and sAA after both tests did not differ between the groups. In conclusion, we demonstrated alterations in diurnal autonomic functioning in children with ADHD and ASD, while hypothalamic-pituitary-adrenal axis functioning did not differ between the clinical and the comparison groups.

Automatic Classification of Adult Males With and Without Autism Spectrum Disorder by Non-contact Measurement of Autonomic Nervous System Activation

People with autism spectrum disorder (ASD) exhibit atypicality in various domains of behavior. Previous psychophysiological studies have revealed an atypical pattern of autonomic nervous system (ANS) activation induced by psychosocial stimulation. Thus, it might be feasible to develop a novel assessment tool to evaluate the risk of ASD by measuring ANS activation in response to emotional stimulation. The present study investigated whether people with ASD could be automatically classified from neurotypical adults based solely on physiological data obtained by the recently introduced non-contact measurement of pulse wave. We video-recorded faces of adult males with and without ASD while watching emotion-inducing video clips. Features reflective of ANS activation were extracted from the temporal fluctuation of facial skin coloration and entered into a machine-learning algorithm. Though the performance was modest, the gradient boosting classifier succeeded in classifying people with and without ASD, which indicates that facial skin color fluctuation contains information useful for detecting people with ASD. Taking into consideration the fact that the current study recruited only high-functioning adults who have relatively mild symptoms and probably developed some compensatory strategies, ASD screening by non-contact measurement of pulse wave could be a promising assessment tool to evaluate ASD risk.

Brief Report: Reduced Heart Rate Variability in Children with Autism Spectrum Disorder

Dysregulation of the autonomic nervous system (ANS), which can be indexed by heart rate variability (HRV), has been posited to contribute to core features of autism spectrum disorder (ASD). However, the relationship between ASD and HRV remains uncertain. We assessed tonic and phasic HRV of 21 children with ASD and 21 age- and IQ-matched typically developing (TD) children and examined (1) group differences in HRV and (2) associations between HRV and ASD symptomatology. Children with ASD showed significantly lower tonic HRV, but similar phasic HRV compared to TD children. Additionally, reduced tonic HRV was associated with atypical attentional responsivity in ASD. Our findings suggest ANS dysregulation is present in ASD and may contribute to atypical attentional responses to sensory stimulation.

IQ and Internalising Symptoms in Adolescents with ASD

Intelligence quotient (IQ), has been found to relate to the presence of internalising symptoms in autism spectrum disorder (ASD). This meta-analysis sought to clarify the direction of the relationship between IQ and two prevalent internalising symptoms, anxiety and depression, in adolescents with ASD. Secondly, this study aimed to highlight methodological factors contributing to inconsistent findings in existing research. Self-reported anxiety was found to be significantly higher in youth with a lower IQ, while depression was positively associated with IQ. Consequently, parents, schools and clinicians should be cautious of underestimating anxiety in youth with a lower IQ. However, care should also be taken to ensure adolescents with ASD without intellectual disabilities are not overlooked with regards to social and emotional support.

The Safety and Effectiveness of High-Dose Propranolol as a Treatment for Challenging Behaviors in Individuals With Autism Spectrum Disorders

PURPOSE/BACKGROUND

Individuals with autism spectrum disorders present with social communication deficits and a rigid adherence to sameness. Along with these symptoms, many individuals also present with severe challenging behaviors that place themselves as well as their families and communities at risk for injury. For these individuals, new and effective treatments are acutely needed. Propranolol has been used worldwide for over 50 years. Its primary indication is for hypertension, but there is evidence that, at higher doses, propranolol inhibits rage and anger through its effects on the central nervous system. This effect has been demonstrated in a variety of neuropsychiatric disorders.

METHODS/PROCEDURES

Here, we present 46 retrospective analyses of clinical cases that were followed by a psychiatrist. Propranolol was prescribed as an add-on to the patients' existing medications. The doses ranged from 120 to 960 mg per day (mean = 462 mg).

FINDINGS/RESULTS

Thirty-nine (85%) of 46 patients were found to be much improved or very much improved on the physician-rated Clinical Global Impression Improvement scale. There were few side effects noted, with only 2 subjects unable to tolerate the propranolol.

IMPLICATIONS/CONCLUSIONS

It appears that high-dose propranolol can be given safely with minimal adverse cardiovascular problems, provided that close clinical monitoring is maintained. A more rigorous clinical trial is needed to elucidate and verify its clinical utility, clinical practice parameters, and the effects of propranolol as a monotherapy versus as an add-on to the patient's existing medication regimen.

The Relationship between Autism and Ehlers-Danlos Syndromes/Hypermobility Spectrum Disorders

Considerable interest has arisen concerning the relationship between hereditary connective tissue disorders such as the Ehlers-Danlos syndromes (EDS)/hypermobility spectrum disorders (HSD) and autism, both in terms of their comorbidity as well as co-occurrence within the same families. This paper reviews our current state of knowledge, as well as highlighting unanswered questions concerning this remarkable patient group, which we hope will attract further scientific interest in coming years. In particular, patients themselves are demanding more research into this growing area of interest, although science has been slow to answer that call. Here, we address the overlap between these two spectrum conditions, including neurobehavioral, psychiatric, and neurological commonalities, shared peripheral neuropathies and neuropathologies, and similar autonomic and immune dysregulation. Together, these data highlight the potential relatedness of these two conditions and suggest that EDS/HSD may represent a subtype of autism.

Heart Rate Variability in Children With Autism Spectrum Disorder and Associations With Medication and Symptom Severity

Decreased heart rate variability (HRV) is considered a common marker of autonomic dysfunction that contributes to poor health outcomes. While some studies have suggested that children with autism spectrum disorder (ASD) show reduced HRV, research is yet to consider whether this may be associated with medication use and symptom severity. This study examined the relationship between resting state HRV, medication use and symptom severity in children diagnosed with ASD. Children with ASD (N = 86), aged between 3 and 12 years (M = 8.09), were compared to 44 neurotypical children of similar age (M = 7.15). Laboratory assessment of HRV involved 5 min of non-invasive baseline electrocardiogram assessments while participants viewed an age-appropriate non-verbal animated video. Time-domain and frequency-domain HRV measures were analyzed. ASD symptom severity was assessed using the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) and Social Responsiveness Scale (SRS-2). Results indicated that children with ASD exhibited reduced resting HRV relative to neurotypical children. Subsequent analyses within the ASD group suggested that this group difference was greater in children who were taking psychotropic medication (N = 36). Our data also provides tentative evidence of a relationship between HRV and social impairment symptoms in children with ASD, with more severe repetitive behaviors (as measured by the ADOS-2) associated with decreased resting HRV. Overall, these findings suggest that HRV may be atypical in children with ASD and suggest the importance of exploring HRV as a risk factor for cardiovascular health in this group. LAY SUMMARY: Cardiac activity, such as heart rate variability (HRV), can provide insight into the autonomic nervous system. This study reports on the association between resting-state HRV and autonomic nervous system activity in young children with autism spectrum disorder (ASD) compared to neurotypical children. These results may help us understand what underlies autonomic nervous system dysfunction and the potential pathophysiological mechanisms leading to increased cardiovascular risk in ASD.

Transcranial Magnetic Stimulation in Autism Spectrum Disorders: Neuropathological Underpinnings and Clinical Correlations

Despite growing knowledge about autism spectrum disorder (ASD), research findings have not been translated into curative treatment. At present, most therapeutic interventions provide for symptomatic treatment. Outcomes of interventions are judged by subjective endpoints (eg, behavioral assessments) which alongside the highly heterogeneous nature of ASD account for wide variability in the effectiveness of treatments. Transcranial magnetic stimulation (TMS) is one of the first treatments that targets a putative core pathologic feature of autism, specifically the cortical inhibitory imbalance that alters gamma frequency synchronization. Studies show that low frequency TMS over the dorsolateral prefrontal cortex of individuals with ASD decreases the power of gamma activity and increases the difference between gamma responses to target and nontarget stimuli. TMS improves executive function skills related to self-monitoring behaviors and the ability to apply corrective actions. These improvements manifest themselves as a reduction of stimulus bound behaviors and diminished sympathetic arousal. Results become more significant with increasing number of sessions and bear synergism when used along with neurofeedback. When applied at low frequencies in individuals with ASD, TMS appears to be safe and to improve multiple patient-oriented outcomes. Future studies should be conducted in large populations to establish predictors of outcomes (eg, genetic profiling), length of persistence of benefits, and utility of booster sessions.

Atypical Emotional Electrodermal Activity in Toddlers with Autism Spectrum Disorder

Past studies in autism spectrum disorder (ASD) indicate atypical peripheral physiological arousal. However, the conditions under which these atypicalities arise and their link with behavioral emotional expressions and core ASD symptoms remain uncertain. Given the importance of physiological arousal in affective, learning, and cognitive processes, the current study examined changes in skin conductance level (ΔSCL) in 41 toddlers with ASD (mean age: 22.7 months, SD: 2.9) and 32 age-matched toddlers with typical development (TD) (mean age: 21.6 months, SD: 3.6) in response to probes designed to induce anger, joy, and fear emotions. The magnitude of ΔSCL was comparable during anger (P = 0.206, d = 0.30) and joy (P = 0.996, d = 0.01) conditions, but significantly lower during the fear condition (P = 0.001, d = 0.83) in toddlers with ASD compared to TD peers. In the combined samples, ΔSCL positively correlated with intensity of behavioral emotional expressivity during the anger (r[71] = 0.36, P = 0.002) and fear (r[68] = 0.32, P = 0.007) conditions, but not in the joy (r[69] = -0.15, P = 0.226) condition. Finally, ΔSCL did not associate with autism symptom severity in any emotion-eliciting condition in the ASD group. Toddlers with ASD displayed attenuated ΔSCL to situations aimed at eliciting fear, which may forecast the emergence of highly prevalent internalizing and externalizing problems in this population. The study putatively identifies ΔSCL as a dimension not associated with severity of autism but with behavioral responses in negatively emotionally challenging events and provides support for the feasibility, validity, and incipient utility of examining ΔSCL in response to emotional challenges in very young children. LAY SUMMARY: Physiological arousal was measured in toddlers with autism exposed to frustrating, pleasant, and threatening tasks. Compared to typically developing peers, toddlers with autism showed comparable arousal responses to frustrating and pleasant events, but lower responses to threatening events. Importantly, physiological arousal and behavioral expressions were aligned during frustrating and threatening events, inviting exploration of physiological arousal to measure responses to emotional challenges. Furthermore, this study advances the understanding of precursors to emotional and behavioral problems common in older children with autism. Autism Res 2020, 13: 1476-1488. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

Evaluation of sympathetic sudomotor responses to auditory stimuli in children with autism spectrum disorders

AIM AND OBJECTIVE

Autism spectrum disorder (ASD) being a complex neurological and developmental disorder is also associated with autonomic nervous system dysfunction. Sudomotor nerve function is one highly sensitive index of sympathetic cholinergic activity and can be evaluated by measuring sympathetic skin response (SSR) to various stimuli. Studies reporting SSR to auditory stimulus among ASDs are limited and to the extent of our knowledge not assessed in the Indian scenario. The objective of the study was to assess and compare sympathetic sudomotor activity by evaluating SSR to auditory stimuli in children with and without ASDs.

MATERIALS AND METHODS

A total of eighty individuals were enrolled in the study, including forty children with ASD and forty typically developing (TD) children. SSR to auditory stimulus was assessed using a digitized data acquisition unit in a soundproof room, maintained at 23°C. SSR indices such as latent period (s), amplitude (mv), and habituation were analyzed and compared using appropriate statistical tests between the groups. P < 0.05 was considered statistically significant.

RESULTS

Habituation for SSR was statistically significantly lower (P < 0.001) in children with ASD (0.43 [0.21, 0.61]) compared to TD children (0.78 [0.65, 0.95]). Latent period was also statistically significantly higher in children with ASD (1.67 [1.37, 2.02]) compared to TD children (1.41 [1.2, 1.72]). However, there was no significant difference in amplitude values between the groups.

CONCLUSIONS

Children with ASDs exhibited slower habituation of SSR to auditory stimuli compared to healthy controls. This slower habituation process might be due to the persistent predominant state of sympathetic nerves, which, in turn, contributes to the atypical emotional and behavioral traits prevailing in ASDs.

Trial-to-Trial Variability in Electrodermal Activity to Odor in Autism

Abnormal trial-to-trial variability (TTV) has been identified as a key feature of neural processing that is related to increased symptom severity in autism. The majority of studies evaluating TTV have focused on cortical processing. However, identifying whether similar atypicalities are evident in the peripheral nervous system will help isolate perturbed mechanisms in autism. The current study focuses on TTV in responses from the peripheral nervous system, specifically from electrodermal activity (EDA). We analyzed previously collected EDA data from 17 adults with autism and 19 neurotypical controls who viewed faces while being simultaneously exposed to fear (fear-induced sweat) and neutral odors. Average EDA peaks were significantly smaller and TTV was reduced in the autism group compared to controls, particularly during the fear odor condition. Amplitude and TTV were positively correlated in both groups, but the relationship was stronger in the control group. In addition, TTV was reduced in those with higher Autism Quotient scores but only for the individuals with autism. These findings confirm the existing results that atypical TTV is a key feature of autism and that it reflects symptom severity, although the smaller TTV in EDA contrasts with the previous findings of greater TTV in cortical responses. Identifying the relationship between cortical and peripheral TTV in autism is key for furthering our understanding of autism physiology. LAY SUMMARY: We compared the changes in electrodermal activity (EDA) to emotional faces over the course of repeated faces in adults with autism and their matched controls. The faces were accompanied by smelling fear-inducing odors. We found smaller and less variable responses to the faces in autism when smelling fear odors, suggesting that the peripheral nervous system may be more rigid. These findings were exaggerated in those who had more severe autism-related symptoms.

The Importance of Adolescent Self-Report in Autism Spectrum Disorder: Integration of Questionnaire and Autonomic Measures

Anxiety and sensory symptoms are highly prevalent and meaningful in the daily lives of individuals with autism spectrum disorder (ASD). Despite the importance of carefully measuring, researching, and treating these symptoms, current methods in ASD seldom include self-report. This study investigated the consistency of adolescent and parent reports of anxiety and auditory sensitivity in individuals with ASD, and examined their validity via comparisons with sympathetic arousal at baseline and in response to an auditory challenge. Fifty adolescent-parent dyads (n = 26 ASD, n = 24 typically developing; 12-16 years old; IQ>80) completed parallel versions of both anxiety and auditory hypersensitivity scales, which were compared to heart rate collected at rest and during an aversive noise task. Adolescents with ASD exhibited greater anxiety and auditory hypersensitivity than their peers, based on both self and parent report. Across groups, self-report was higher than parent report. In individuals with ASD, a significant relationship was found between self-reported anxiety and autonomic arousal at rest, and between self-reported auditory sensitivity and autonomic reactivity during the noise task. These relationships were not significant for parent-report. These findings extend past work by demonstrating greater self-reported (than parent-reported) anxiety and sensory symptoms. Furthermore, the presence of significant correlations between self-reported symptoms and sympathetic arousal supports the validity of self-report in adolescents with ASD with average or above average cognitive abilities. This indicates that adolescents with ASD have a unique perspective on their internal experience, which can complement parent reports and provide a more comprehensive assessment of symptoms in research and clinical settings.

Physiological arousal and observed behaviour in parent-child interactions involving young children with Down syndrome

BACKGROUND

Parents of children with Down syndrome (DS) play an important role in their child's development. Physiological measures, such as electrodermal activity (EDA), can shed light on parent-child relations beyond the behavioural level. The goals of the current study were to assess the feasibility of collecting EDA data in preschool age children with DS, examine the association between parent and child EDA during play-based interactions, and investigate the relation between parent and child EDA and observed parent behaviours.

METHOD

Two parents in 15 families participated in dyadic free play interactions with their child with DS (i.e., 15 mother-child and 15 father-child interactions). The children with DS (aged 24-61 months) and both of their parents wore multisensory wristbands measuring EDA. Parent behaviours were coded as requests for behavioural complies, requests for verbal complies, or comments.

RESULTS

Usable EDA data were collected for 13/15 children and 11/15 mothers during the mother-child interactions and 14/15 children and 12/15 fathers during the father-child interactions. Parent and child EDA variability was significantly positively related for father-child but not mother-child dyads. Maternal use of requests for behavioural complies was positively related to child EDA variability.

CONCLUSIONS

The collection of EDA data through wristbands worn by young children with DS during early parent-child interactions was feasible. Preliminary findings indicated that some aspects of parent and child physiology in DS may be related in different ways for mother-child and father-child dyads.

Exploring Key Physiological System Profiles at Rest and the Association with Depressive Symptoms in Autism Spectrum Disorder

Depression is often associated with dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). Individuals with autism spectrum disorder (ASD) may experience physiological dysregulation and psychological comorbidities; however, the extent to which the interactions between these systems predict internalizing symptoms in ASD has not been investigated. The study examined interactions with the HPA axis and ANS in 10-13-year-old children with ASD (n = 41) and typical development (TD; n = 46). The interrelated systems uniquely contributed to depressive symptoms in ASD above and beyond any system in isolation. A reciprocal, parasympathetic-dominant ANS was related to fewer affective symptoms in ASD. Findings highlight the importance of examining arousal across multiple systems to more precisely identify profiles associated with maladaptive psychiatric outcomes in ASD.

Screen Time and Children with Autism Spectrum Disorder

BACKGROUND

Research is increasingly raising concerns regarding the negative consequences of children's use of screens.

SUMMARY

This article reviews the literature on the benefits and risks of screen time with attention to explaining possible reasons that children with autism are more at risk for the negative effects of screen time. Based on the science of learning literature, a framework for choosing appropriate digital media for children with autism is described. The 3-component framework considers the characteristics of the child, the context in which digital media are used, and the content of the media. Key Message: Using the framework, the speech-language pathologist will be better able to select appropriate digital media content for children with autism that is engaging (while not being distracting), encourages the child to be actively involved with the media, is meaningful in the child's life, and incorporates social interactions with others.