Sex differences in sensory processing in children with autism spectrum disorder

Associations Between Autism Spectrum Quotient and Integration of Visual Stimuli in 9-year-old Children: Preliminary Evidence of Sex Differences

PURPOSE

The dorsal stream vulnerability hypothesis posits that the dorsal stream, responsible for visual motion and visuo-motor processing, may be particularly vulnerable during neurodevelopment. Consistent with this, autism spectrum disorder (ASD) has been associated with deficits in global motion integration, though deficits in ventral stream tasks, such as form identification, have also been reported. In the current study, we examined whether a similar pattern of results is found in a cohort of 381 children born with neurodevelopmental risk factors and exhibiting a wide spectrum of caregiver-reported autistic traits.

METHODS

We examined the associations between global motion perception, global form perception, fine motor function, visual-motor integration, and autistic traits (autism spectrum quotient, AQ) using linear regression, accounting for possible interactions with sex and other factors relevant to neurodevelopment.

RESULTS

All assessments of dorsal stream function were significantly associated with AQ such that worse performance predicted higher AQ scores. We also observed a significant sex interaction, with worse global form perception associated with higher AQ in boys (n = 202) but not girls (n = 179).

CONCLUSION

We found widespread associations between dorsal stream functions and autistic traits. These associations were observed in a large group of children with a range of AQ scores, demonstrating a range of visual function across the full spectrum of autistic traits. In addition, ventral function was associated with AQ in boys but not girls. Sex differences in the associations between visual processing and neurodevelopment should be considered in the designs of future studies.

Atypical Sensory Processing in Neurodevelopmental Disorders: Clinical Phenotypes in Preschool-Aged Children

BACKGROUND

Sensory processing issues are frequent in neurodevelopmental disorders (NDDs), with very variable prevalence rates ranging from 20% to 95%. This study aimed to investigate sensory processing in preschool-aged children with NDDs, to clarify the epidemiology, and to identify associated or correlated clinical and psychometric variables.

METHODS

A total of 141 NDD children (age range 2-5 years old) were included and enrolled in two subgroups: 72 with ASD and 69 with other NDDs. A standardized neuropsychological evaluation was assessed (Griffiths III/WPPSI-III/Leiter-R, ADOS-2) and the parents completed the CBCL ½-5, the SPM-P, and the ADI-R.

RESULTS

Atypical sensory processing was reported in 39.7% of the total sample, more frequently in ASD (44.4%) than in other NDDs (34.8%). No statistically significant differences were found regarding gender and developmental level. A positive correlation was found between sensory processing abnormalities and behavioral problems (p < 0.01).

CONCLUSIONS

Compared to other NDDs, ASDs more frequently have atypical sensory processing and appear to present a specific vulnerability in the processing of proprioceptive and vestibular inputs. Our results suggest that sensory processing difficulties should be considered regardless of developmental level and in children with behavioral problems.

Convergent validity of two adult self-report sensory scales: Comparing the Adolescent/Adult Sensory Profile and the Sensory Processing Measure 2-Adult Form

INTRODUCTION

Occupational therapists use standardised scales and measures to assess an individual's sensory processing factors. To date, few studies have investigated the correlations between the Adolescent/Adult Sensory Profile (A/ASP) and the Sensory Processing Measure 2-Adult Form (SPM-2-Adult). The aim of the project is to investigate the association between the sensory processing factors measured by the A/ASP and SPM-2-Adult when completed by the same group of adult participants, with an additional research question investigating whether any significant differences existed between sensory processing scores based on participants' self-reported gender identity.

METHODS

Forty-two adults aged 18-30 completed the A/ASP and the SPM-2-Adult. Associations between the A/ASP quadrant and the SPM-2-Adult subscales were examined using Spearman's rho correlation coefficients, and differences between participants based on their self-reported gender identity were investigated using Mann-Whitney U tests.

RESULTS

Statistically significant correlations were obtained between the A/ASP Low Registration, Sensory Sensitivity, and Sensation Avoiding quadrant subscales and all nine of the SPM-2-Adult subscales ranging from weak (rho = 0.342, p < 0.027) to strong (rho = 0.790, p < 0.001) correlations. The A/ASP Sensation Seeking quadrant subscale was only significantly correlated with the SPM-2-Adult Social Participation subscale (rho = -0.416, p = 0.006). Three subscales had statistically significant differences based on gender identity: SPM-2-Adult Vision (p = 0.007), SPM-2-Adult Sensory Total (p = 0.048), and A/ASP Sensory Sensitivity (p = 0.043).

CONSUMER AND COMMUNITY INVOLVEMENT

Consumers and community members were not involved in the design, execution, or write-up of the study results.

CONCLUSION

The A/ASP and the SPM-2-Adult had several subscales that were significantly correlated with one another. Of note, significant associations were achieved between the A/ASP Low Registration, Sensory Sensitivity, and Sensation Avoiding quadrant subscales and all nine of the SPM-2-Adult subscales. These findings make a significant preliminary contribution to the psychometric body of evidence related to the sensory processing assessment of adults.

Female-specific dysfunction of sensory neocortical circuits in a mouse model of autism mediated by mGluR5 and estrogen receptor α

Little is known of the brain mechanisms that mediate sex-specific autism symptoms. Here, we demonstrate that deletion of the autism spectrum disorder (ASD)-risk gene, Pten, in neocortical pyramidal neurons (NSEPten knockout [KO]) results in robust cortical circuit hyperexcitability selectively in female mice observed as prolonged spontaneous persistent activity states. Circuit hyperexcitability in females is mediated by metabotropic glutamate receptor 5 (mGluR5) and estrogen receptor α (ERα) signaling to mitogen-activated protein kinases (Erk1/2) and de novo protein synthesis. Pten KO layer 5 neurons have a female-specific increase in mGluR5 and mGluR5-dependent protein synthesis. Furthermore, mGluR5-ERα complexes are generally elevated in female cortices, and genetic reduction of ERα rescues enhanced circuit excitability, protein synthesis, and neuron size selectively in NSEPten KO females. Female NSEPten KO mice display deficits in sensory processing and social behaviors as well as mGluR5-dependent seizures. These results reveal mechanisms by which sex and a high-confidence ASD-risk gene interact to affect brain function and behavior.

Retinal GABAergic Alterations in Adults with Autism Spectrum Disorder

Alterations in γ-aminobutyric acid (GABA) have been implicated in sensory differences in individuals with autism spectrum disorder (ASD). Visual signals are initially processed in the retina, and in this study, we explored the hypotheses that the GABA-dependent retinal response to light is altered in individuals with ASD. Light-adapted electroretinograms were recorded from 61 adults (38 males and 23 females; n = 22 ASD) in response to three stimulus protocols: (1) the standard white flash, (2) the standard 30 Hz flickering protocol, and (3) the photopic negative response protocol. Participants were administered an oral dose of placebo, 15 or 30 mg of arbaclofen (STX209, GABAB agonist) in a randomized, double-blind, crossover order before the test. At baseline (placebo), the a-wave amplitudes in response to single white flashes were more prominent in ASD, relative to typically developed (TD) participants. Arbaclofen was associated with a decrease in the a-wave amplitude in ASD, but an increase in TD, eliminating the group difference observed at baseline. The extent of this arbaclofen-elicited shift significantly correlated with the arbaclofen-elicited shift in cortical responses to auditory stimuli as measured by using an electroencephalogram in our prior study and with broader autistic traits measured with the autism quotient across the whole cohort. Hence, GABA-dependent differences in retinal light processing in ASD appear to be an accessible component of a wider autistic difference in the central processing of sensory information, which may be upstream of more complex autistic phenotypes.

An evaluation of the German version of the Sensory Perception Quotient from an expert by experience perspective

Sensory processing is often altered in individuals with autism; thus, it is essential to develop reliable measurement tools to assess sensory perception. The Sensory Perception Quotient (SPQ) quantifies basic sensory sensitivities in adults via self-report. Adopting an expert by experience perspective, this study aimed to evaluate a German translation of the SPQ for its use in clinical and research applications, especially for autistic adults. 108 adults (n = 54 autistic) completed the German SPQ in an online assessment. A 92-item and a 35-item version of the German SPQ were analyzed for group differences and internal consistency. Our results show that adults with autism reported greater sensory sensitivity compared to non-autistic adults. Results further suggest good to excellent internal consistency for the 95-item and 35-item SPQ translations. This finding was supported by the correlative relationship between sensory sensitivity and autistic traits. These findings confirm the reliability of our SPQ translation, making it a suitable German assessment tool for basic sensory sensitivity in autistic adults.

Female specific dysfunction of sensory neocortical circuits in a mouse model of autism mediated by mGluR5 and Estrogen Receptor α

Autism manifests differently in males and females and the brain mechanisms that mediate these sex-dependent differences are unknown. Here, we demonstrate that deletion of the ASD-risk gene, Pten, in neocortical pyramidal neurons (NSE Pten KO) results in robust hyperexcitability of local neocortical circuits in female, but not male, mice, observed as prolonged, spontaneous persistent activity states (UP states). Circuit hyperexcitability in NSE Pten KO mice is mediated by enhanced and/or altered signaling of metabotropic glutamate receptor 5 (mGluR5) and estrogen receptor α (ERα) to ERK and protein synthesis selectively in Pten deleted female neurons. In support of this idea, Pten deleted Layer 5 cortical neurons have female-specific increases in mGluR5 and mGluR5-driven protein synthesis. In addition, mGluR5-ERα complexes are elevated in female cortex and genetic reduction of ERα in Pten KO cortical neurons rescues circuit excitability, protein synthesis and enlarged neurons selectively in females. Abnormal timing and hyperexcitability of neocortical circuits in female NSE Pten KO mice are associated with deficits in temporal processing of sensory stimuli and social behaviors as well as mGluR5-dependent seizures. Female-specific cortical hyperexcitability and mGluR5-dependent seizures are also observed in a human disease relevant mouse model, germline Pten +/- mice. Our results reveal molecular mechanisms by which sex and a high impact ASD-risk gene interact to affect brain function and behavior.

Is There a Bias Towards Males in the Diagnosis of Autism? A Systematic Review and Meta-Analysis

Autism is more frequently diagnosed in males, with evidence suggesting that females are more likely to be misdiagnosed or underdiagnosed. Possibly, the male/female ratio imbalance relates to phenotypic and camouflaging differences between genders. Here, we performed a comprehensive approach to phenotypic and camouflaging research in autism addressed in two studies. First (Study 1 - Phenotypic Differences in Autism), we conducted a systematic review and meta-analysis of gender differences in autism phenotype. The electronic datasets Pubmed, Scopus, Web of Science, and PsychInfo were searched. We included 67 articles that compared females and males in autism core symptoms, and in cognitive, socioemotional, and behavioural phenotypes. Autistic males exhibited more severe symptoms and social interaction difficulties on standard clinical measures than females, who, in turn, exhibited more cognitive and behavioural difficulties. Considering the hypothesis of camouflaging possibly underlying these differences, we then conducted a meta-analysis of gender differences in camouflaging (Study 2 - Camouflaging Differences in Autism). The same datasets as the first study were searched. Ten studies were included. Females used more compensation and masking camouflage strategies than males. The results support the argument of a bias in clinical procedures towards males and the importance of considering a 'female autism phenotype'-potentially involving camouflaging-in the diagnostic process.

Could Sensory Differences Be a Sex-Indifferent Biomarker of Autism? Early Investigation Comparing Tactile Sensitivity Between Autistic Males and Females

Sensory differences are highly prevalent in autistic individuals. However, few studies have compared their presentation between autistic males and autistic females. We used psychophysics to assess and compare tactile perceptual sensitivity between autistic and non-autistic boys and girls aged between 8 and 12 years of age. While there were sex-differences of amplitude discrimination, frequency discrimination and order judgement thresholds, these sex-differences were not autism-specific. Mean RTs and detection thresholds were elevated in autism but were comparable between the sexes. Tactile sensitivity measures that are elevated in autism but are otherwise comparable between autistic males and autistic females suggest the possibility that certain sensory features could be used as sex-indifferent markers of autism. Further investigation with larger and more representative samples should be conducted before any stronger conclusions are made.

Autistic phenomenology: past, present, and potential future

We are now at a transition point in autism conceptualisation, science, and clinical practise, where phenomenology could play a key role. This paper takes a broad view of the history of phenomenological perspectives on the autism concept and how this has evolved over time, including contemporaneous theory and methods. Early inquiry from a clinical perspective within the tradition of classical continental phenomenology, linked closely to the consideration of schizophrenia, is contrasted with emerging observations of child development and a period in the second half of the twentieth century of scientific inquiry into a behavioural autistic phenotype where there was little or no phenomenological aspect; a phenotype that has determined the recent scientific and clinical conceptualisation of autism within current nosology. We then mark a more recent reawakening of interdisciplinary interest in subjective experience and phenomenological inquiry, which itself coincides with the increasing prominence and salience of the neurodiversity movement, autistic advocacy, and critical autism studies. We review this emerging phenomenological work alongside a contemporaneous clinical phenomenology perspective and representations of autistic experience from within the extensive literature (including life writing) from autistic people themselves; all perspectives that we argue need now be brought into juxtaposition and dialogue as the field moves forward. We argue from this for a future which could build on such accounts at a greater scale, working toward a more co-constructed, systematic, representative, and empirical autistic phenomenology, which would include citizen and participatory science approaches. Success in this would not only mean that autistic experience and subjectivity would be re-integrated back into a shared understanding of the autism concept, but we also argue that there could be the eventual goal of an enhanced descriptive nosology, in which key subjective and phenomenological experiences, discriminating for autism, could be identified alongside current behavioural and developmental descriptors. Such progress could have major benefits, including increased mutual empathy and common language between professionals and the autistic community, the provision of crucial new foci for research through aspects of autistic experience previously neglected, and potential new supportive innovations for healthcare and education. We outline a programme and methodological considerations to this end.

Differences in temporal profile of brain responses by pleasantness of somatosensory stimulation in autistic individuals

Purpose/Aim. Autistic individuals may show either hyper- or hypo- responsiveness to touch compared to non-autistic individuals. These behavioural responses depend on perceptual and evaluative mechanisms, which unfold sequentially and thus can be distinguished by exploring the timing of neural responses. In this study, we examined neural response timing to pleasant, unpleasant, and affectively neutral textures, to determine whether these perceptual versus evaluative subprocesses differ in autism and how each subprocess contributes to behavioural responses.Materials and Methods. Our sample included n = 13 autistic and n = 14 non-autistic adults who completed functional magnetic resonance imaging. We analysed early, intermediate, and late phases of the tactile response, derived from studies of noxious tactile stimulation, to three different textures.Results. The autistic group showed distinct differences from the non-autistic group to each of the textures, showing earlier, somatosensory differences in response to the pleasantly and unpleasantly rated textures and later, frontomotor differences in response to the neutrally rated texture. Further, reduced early phase response to the pleasant texture correlated with increased sensory seeking behaviour.Conclusions. While preliminary, these results suggest distinct patterns between autistic and non-autistic individuals in how the neural response to touch unfolds and its correspondence with the perceived pleasantness of tactile experience. The findings suggest perceptual differences in response to affectively charged textures and evaluative differences in response to neutral, ambiguous textures. These temporal properties may inform future studies of tactile processing in autism, lending a better understanding of how individuals differ in their sensory experiences across contexts.

The Relationship Between Social Skills and Sensory Profile, Emotion Regulation, and Empathizing/Systemizing in Adolescents on the Autism Spectrum

This study aims to evaluate the relationship between social skills and sensory features, emotion regulation, and empathy in adolescents on the autism spectrum. One hundred and twenty-three adolescents were included in the study (50 autistic, 73 typically developing-TD adolescents). The participants filled out the Adolescent/Adult Sensory Profile (AASP) and Emotion Regulation Questionnaire. Parents of the participants completed the Child Empathy and Systemizing Quotient (EQ-C/SQ-C) and Autism-Social Skills Profile (ASSP) scales. Social reciprocity, social participation/avoidance, ASSP total scores, empathy and systemizing scores were lower, and detrimental social behaviors, low registration sensory profile scores were higher in the autism spectrum group. While a difference between genders was observed in sensory sensitivity, sensation avoiding, low registration quadrants and empathy scores, no gender and group interaction was found in any domain. Social skill total scores were correlated to sensation seeking and low registration sensory features, empathy, systemizing, and reappraisal emotion regulation scores. A hierarchical multiple linear regression analysis was conducted controlling for group and gender, sensation seeking (p = .032, β = 0.138), low registration (p = .012, β = - 0.215) of the AASP, and empathy (p < .001, β = 0.555) and systemizing (p = .033, β = 0.138) scores of the EQ/SQ-C was found to significantly predict social skill total scores. Although emotional regulation strategies may play a role, sensory processing features and empathy and systemizing skills seem to be the more significant contributors to social skills during adolescence. Interventions targeting sensory processing and especially improving empathy and systematization skills may positively affect social skills in adolescents on the autism spectrum.

Barriers to an Autistic Identity: How RRBs may Contribute to the Underdiagnosis of Females

Background

Autistic females are frequently underdiagnosed, misdiagnosed, and/or diagnosed later in life. Restricted and Repetitive Behaviors (RRBs) are increasingly critical for diagnosis and yet are commonly rated lower in females. Whether this reflects genuinely lower levels of these traits, or if female-typical RRBs have a different phenotypic presentation that may not register on current quantitative measurement tools is unclear.

Methods

Twenty-one autistic females and 21 autistic males matched on chronological age and FSIQ completed the AQ, ADOS-2, and ADI-R. Items from the ADOS-2 and ADI-R were selected that were relevant to the four areas of restricted and repetitive behavior in the DSM-5 diagnostic criteria of autism. Using a mixed-methods analytical approach, scores and comments on these measures were compared between sexes to better characterize RRBs in autistic females.

Results

There were no sex differences on the AQ, which broadly assesses autistic traits. When analyzed by the four DSM-5 RRB criteria, there were no sex differences on the ADI-R when using traditional algorithm scoring that narrows questions down to those that are more sensitive and specific in capturing autism in research samples with a high proportion of males. When incorporating additional items relevant to the DSM-5 to identify sex changes in a broader pool of items, females scored higher on stereotyped movements and speech. Females also engaged in more sensory behaviors during the ADOS-2. Qualitative analyses indicated that females were more likely to engage in stereotyped body rocking and spinning, stereotyped behaviors when anxious, to show major reactions to changes, repetitive language including listing and counting, and sensory behaviors, especially in the tactile domain.

Conclusion

Exploratory findings highlight sex differences in RRBs that may help enhance diagnostic clarity for females. Higher tactile sensory behaviors in females suggests there may be increased diagnostic sensitivity for females with the updated DSM-5 that now includes sensory components as part of the diagnostic criteria.

Similar overall expression, but different profiles, of autistic traits, sensory processing, and mental health between young adult males and females

Recent trends suggest that autism is more common in females than traditionally held. Additionally, some argue that females express autistic traits differently than males. Dimensional views of autism could shed light on these issues, especially with regards to understudied behavioral areas, such as sensory processing. We examined autistic traits, sensory processing, anxiety, and related behaviors in a large sample of neurotypical young adult males and females (n = 1,122; 556 female; ages 19-26). Participants completed an online survey containing questionnaires related to the above. Between groups statistical analyses, as well as within groups correlations and mediation analyses containing these constructs were then computed. We also carried out a cluster analysis to establish groups with behavioral similarities and estimate within-cluster male/female ratios. Results showed modest differences in the overall expression of autistic traits and sensory processing, if any, between males and females. Conversely, more detailed examination of survey subtests and mediation analyses revealed differing profiles between these groups. Cluster analysis uncovered a group comprised of both males (69.8%) and females (30.2%) who exhibited elevated degrees of autism-related behaviors, suggesting a higher proportion of females than would be predicted by traditional ratios. Taken together, these findings suggest that males and females may not differ as much as previously thought in their general levels of autistic traits or sensory processing, but may present with distinct profiles of such behaviors. These novel results add to our understanding of autistic traits in females and have the potential to positively influence diagnostic and support practices.

Exploratory evidence for differences in GABAergic regulation of auditory processing in autism spectrum disorder

Altered reactivity and responses to auditory input are core to the diagnosis of autism spectrum disorder (ASD). Preclinical models implicate ϒ-aminobutyric acid (GABA) in this process. However, the link between GABA and auditory processing in humans (with or without ASD) is largely correlational. As part of a study of potential biosignatures of GABA function in ASD to inform future clinical trials, we evaluated the role of GABA in auditory repetition suppression in 66 adults (n = 28 with ASD). Neurophysiological responses (temporal and frequency domains) to repetitive standard tones and novel deviants presented in an oddball paradigm were compared after double-blind, randomized administration of placebo, 15 or 30 mg of arbaclofen (STX209), a GABA type B (GABAB) receptor agonist. We first established that temporal mismatch negativity was comparable between participants with ASD and those with typical development (TD). Next, we showed that temporal and spectral responses to repetitive standards were suppressed relative to responses to deviants in the two groups, but suppression was significantly weaker in individuals with ASD at baseline. Arbaclofen reversed weaker suppression of spectral responses in ASD but disrupted suppression in TD. A post hoc analysis showed that arbaclofen-elicited shift in suppression was correlated with autistic symptomatology measured using the Autism Quotient across the entire group, though not in the smaller sample of the ASD and TD group when examined separately. Thus, our results confirm: GABAergic dysfunction contributes to the neurophysiology of auditory sensory processing alterations in ASD, and can be modulated by targeting GABAB activity. These GABA-dependent sensory differences may be upstream of more complex autistic phenotypes.

Sensory Processing Differences in Individuals With Autism Spectrum Disorder: A Narrative Review of Underlying Mechanisms and Sensory-Based Interventions

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties with social interaction and restricted, repetitive patterns of behavior. Altered sensory processing and perception are considered characteristics of ASD. Sensory processing differences (SPDs) are commonly observed in individuals with ASD, leading to atypical responses to sensory stimuli. SPDs refer to the way in which individuals receive, process, and respond to sensory information from the environment. People with SPDs may be hypersensitive (over-reactive) or hyposensitive (under-reactive) to sensory input, or they may experience fragmented or distorted perceptions. These differences can make it difficult for individuals with SPDs to filter out irrelevant sensory information, and to integrate sensory information from different sources. This study intends to investigate the underlying mechanisms contributing to SPDs in individuals with autism and determine the effectiveness of sensory-based therapies in addressing these challenges. The literature suggests that altered neural pathways, sensory gating dysfunction, and atypical sensory modulation contribute to SPDs in individuals with ASD. Assistive technology, environmental changes, and sensory-based interventions like sensory integration therapy (SIT) have all shown promise in improving sensory functioning and reducing associated behavioral issues. However, further research is needed to improve our understanding of sensory processing in autism and to optimize interventions for individuals with ASD.

Exploring the Prognosis: A Longitudinal Follow-Up Study of Children with Sensory Processing Challenges 8-32 Years Later

Sensory integration and processing challenges have been long recognized in children and, more recently, in adults. To understand the long-term prognosis of these challenges, more research is needed on what children with sensory integration and processing challenges look like as adults. Using the Adult/Adolescent Sensory History, researchers followed up with 102 adults who had known sensory integration and processing challenges as children to examine the following questions: What is the current sensory processing status of adults who received sensory-integration-based occupational therapy services as children? And how has the sensory processing status of adults who received sensory-integration-based services changed since childhood? This study compared performance on sensory processing measures completed as children and as adults for a follow-up group of adults. The results revealed that the severity of sensory integration and processing challenges experienced by the follow-up group decreased from childhood, with 51% of the follow-up group now scoring in the "typical" range of sensory processing. Our findings suggest that those children with sensory integration and processing challenges who are recognized and seek occupational therapy services using an ASI approach are likely to have a good long-term prognosis regarding the severity of their sensory processing functioning.

Sensory Processing and Executive Functioning in Autistic Adults

PURPOSE

One of the core features that can be experienced by adults on the autism spectrum is hyper- and hyporeactivity to sensory stimuli. Research suggests that executive functioning (EF) impairments are related to sensory issues. In this study the relationship between sensory processing issues and EF was investigated. We expected sensory processing issues to predict EF impairments.

METHODS

Thirty men and 30 women on the autism spectrum, 20 men and 24 women without autism were included and matched on intelligence and age. Group comparisons were conducted to determine if groups differed regarding self-reported sensory processing issues (GSQ-NL) and self-reports on EF (BRIEF-A). Correlational and regression analyses were carried out to investigate the relationship between self-reports on GSQ-NL and BRIEF-A.

RESULTS

We found significant differences between men and women on the spectrum with regard to sensory processing issues and EF. Hyporeactivity to sensory information explained most of the EF problems.

CONCLUSION

Clinicians should be aware of differences in sensory experiences between adults on the spectrum and non-autistic adults and differences between men and women during assessment and subsequent counselling.

Hemispheric lateralization of white matter microstructure in children and its potential role in sensory processing dysfunction

Diffusion tensor imaging (DTI) studies have demonstrated white matter microstructural differences between the left and right hemispheres of the brain. However, the basis of these hemispheric asymmetries is not yet understood in terms of the biophysical properties of white matter microstructure, especially in children. There are reports of altered hemispheric white matter lateralization in ASD; however, this has not been studied in other related neurodevelopmental disorders such as sensory processing disorder (SPD). Firstly, we postulate that biophysical compartment modeling of diffusion MRI (dMRI), such as Neurite Orientation Dispersion and Density Imaging (NODDI), can elucidate the hemispheric microstructural asymmetries observed from DTI in children with neurodevelopmental concerns. Secondly, we hypothesize that sensory over-responsivity (SOR), a common type of SPD, will show altered hemispheric lateralization relative to children without SOR. Eighty-seven children (29 females, 58 males), ages 8-12 years, presenting at a community-based neurodevelopmental clinic were enrolled, 48 with SOR and 39 without. Participants were evaluated using the Sensory Processing 3 Dimensions (SP3D). Whole brain 3 T multi-shell multiband dMRI (b = 0, 1,000, 2,500 s/mm2) was performed. Tract Based Spatial Statistics were used to extract DTI and NODDI metrics from 20 bilateral tracts of the Johns Hopkins University White-Matter Tractography Atlas and the lateralization Index (LI) was calculated for each left-right tract pair. With DTI metrics, 12 of 20 tracts were left lateralized for fractional anisotropy and 17/20 tracts were right lateralized for axial diffusivity. These hemispheric asymmetries could be explained by NODDI metrics, including neurite density index (18/20 tracts left lateralized), orientation dispersion index (15/20 tracts left lateralized) and free water fraction (16/20 tracts lateralized). Children with SOR served as a test case of the utility of studying LI in neurodevelopmental disorders. Our data demonstrated increased lateralization in several tracts for both DTI and NODDI metrics in children with SOR, which were distinct for males versus females, when compared to children without SOR. Biophysical properties from NODDI can explain the hemispheric lateralization of white matter microstructure in children. As a patient-specific ratio, the lateralization index can eliminate scanner-related and inter-individual sources of variability and thus potentially serve as a clinically useful imaging biomarker for neurodevelopmental disorders.

Sex Differences in the Developmental Trajectories of Autism Spectrum Disorder

Purpose of Review

Females and males are disproportionately diagnosed with autism, a sex difference that has historically represented this neurodevelopmental condition. The current review examines lifespan developmental trajectories of autism based on sex to elucidate behavioral phenotypic differences that may contribute to differential rates of diagnosis.

Recent Findings

We review sex differences in diagnostic criteria: social communication and restricted interests/repetitive behaviors (RRBs). Results suggest RRBs are more indicative of a diagnosis in males, whereas social differences are more indicative of a diagnosis in females. Factors contributing to a later diagnosis in females include social strengths (camouflaging) and diagnostic overshadowing.

Summary

Sex differences in diagnostic criteria may contribute to differential rates of identification in males and females. Sex differences are most pronounced when assessing naturalistic social communication instead of reliance on standardized measure. Numerous future directions are identified including increasing samples of sub-threshold autistic females and evaluating longitudinal sex differences.

Examine sex differences in autism spectrum disorder in school-aged children and adolescents with fluent language

There are noteworthy sex disparities in the prevalence of autism spectrum disorders (ASD), while findings regarding the sex differences in core symptoms are inconsistent. There are few relevant studies on sex differences in mainland China. This study was dedicated to a deeper understanding of the impact of sex differences on the clinical presentation of ASD with fluent language. We retrospectively studied 301 children with ASD (58 females) and utilized raw scores from the ADI-R and ADOS and the intelligence quotient (IQ) to measure symptomatology. Based on the Full-Scale IQ (FS-IQ), a binary split of average, above-average IQ (high-IQ), and below-average IQ (low IQ) occurs at 85. Across the entire sample, males and females are comparable in the FS-IQ, while males scored higher in the Perceptual Reasoning Index (PRI) (F = 7.812, p = 0.006). ADI-R did not find any statistically significant sex differences in the diagnostic cutoff score satisfaction or the raw domain scores. While a significant effect of sex on ADOS social affect domain scores was found in the total sample [λ = 0.970, partial η²  = 0.030, F (3,295) = 3.019, p = 0.030]. Tests of between-subjects effects revealed that males scored higher than females mainly in the ADOS reciprocal social interaction subcategory (partial η²  = 0.022, F = 6.563, p = 0.011). Stratified analysis revealed that the effect of sex on ADOS reciprocal social interaction subcategory scores only significant in the low-IQ children with ASD (partial η²  = 0.092, F = 10.088, p = 0.002). In general, overall cognitive functioning is similar across males and females with ASD, while males have a higher perceptual reasoning ability. Females with ASD are more likely to have comorbid intellectual impairment than males, and they could require additional intervention support. Autistic children with low IQs are more likely to exhibit sex differences in their core symptoms than children with high IQs. Intelligence plays a key role in sex-based differences in the core symptoms of ASD.

Sensory processing in 16p11.2 deletion and 16p11.2 duplication

Deletions and duplications at the chromosomal region of 16p11.2 have a broad range of phenotypic effects including increased likelihood of intellectual disability, autism, attention deficit hyperactivity disorder (ADHD), epilepsy, and language and motor delays. However, whether and how sensory processing is affected has not yet been considered in detail. Parents/caregivers of 38 children with a 16p11.2 deletion and 31 children with a 16p11.2 duplication completed the Sensory Behavior Questionnaire (SBQ) and the Child Sensory Profile 2 (CSP-2) along with other standardized questionnaires assessing autistic traits (SRS-2), ADHD traits (Conners 3), anxiety (SCAS-P) and adaptive behavior (VABS-3). SBQ and CSP-2 responses found that sensory processing differences were clearly evident in both 16p11.2 deletion and 16p11.2 duplication, though there was significant variation in both cohorts. SBQ data indicated the frequency and impact of sensory behavior were more severe when compared to neurotypical children, with levels being similar to autistic children. CSP-2 data indicated over 70% of children displayed clear differences in sensory registration (missing sensory input). Seventy-one percent with 16p11.2 duplications were also unusually sensitive to sensory information and 57% with 16p11.2 duplications were unusually avoidant of sensory stimuli. This first detailed assessment of sensory processing, alongside other clinical features, in relatively large cohorts of children with a 16p11.2 deletion and 16p11.2 duplication demonstrates that sensory processing differences have a profound impact on their lives.

Patterns of sensory modulation by age and sex in young people on the autism spectrum

Sensory modulation symptoms form a diagnostic criterion for autism spectrum disorder and are associated with significant daily functional limitations. Utilizing caregiver report on Short Sensory Profile-2 (SSP-2) for 919 autistic children (3-14.11 years), we examined the expression of sensory modulation symptoms by age and sex and investigated the existence of specific sensory modulation subtypes. Sensory modulation symptoms appeared to peak in frequency during middle childhood, particularly in sensory sensitivity and avoidance. Symptoms associated with sensory hypo-reactivity and seeking tended not differ between age cohorts. Males and females demonstrated similar overall sensory modulation profiles, however, females showed elevated symptoms relating to sensory sensitivity. Model-based cluster analysis revealed five interpretable sensory modulation subtypes which related to symptom severity (low, mid-range, high). Subtypes demonstrating mid-range symptom severity differed in focus on sensory hyper-reactivity or seeking symptoms. The findings of this study report for the first time that age-related differences in sensory modulation symptoms may be associated with sensory hyper-reactivity only. The subtyping results also suggest that sensory modulation symptom severity is a reliable means of classifying variance within autistic children, however, consideration of differences in the behavioral strategies employed by individuals to manage sensory modulation symptoms may inform tailored supportive strategies.

A Machine Learning Approach in Autism Spectrum Disorders: From Sensory Processing to Behavior Problems

Atypical sensory processing described in autism spectrum disorders (ASDs) frequently cascade into behavioral alterations: isolation, aggression, indifference, anxious/depressed states, or attention problems. Predictive machine learning models might refine the statistical explorations of the associations between them by finding out how these dimensions are related. This study investigates whether behavior problems can be predicted using sensory processing abilities. Participants were 72 children and adolescents (21 females) diagnosed with ASD, aged between 6 and 14 years (M = 7.83 years; SD = 2.80 years). Parents of the participants were invited to answer the Sensory Profile 2 (SP2) and the Child Behavior Checklist (CBCL) questionnaires. A collection of 26 supervised machine learning regression models of different families was developed to predict the CBCL outcomes using the SP2 scores. The most reliable predictions were for the following outcomes: total problems (using the items in the SP2 touch scale as inputs), anxiety/depression (using avoiding quadrant), social problems (registration), and externalizing scales, revealing interesting relations between CBCL outcomes and SP2 scales. The prediction reliability on the remaining outcomes was “moderate to good” except somatic complaints and rule-breaking, where it was “bad to moderate.” Linear and ridge regression achieved the best prediction for a single outcome and globally, respectively, and gradient boosting machine achieved the best prediction in three outcomes. Results highlight the utility of several machine learning models in studying the predictive value of sensory processing impairments (with an early onset) on specific behavior alterations, providing evidences of relationship between sensory processing impairments and behavior problems in ASD.

Atypical sensory processing features in children with autism, and their relationships with maladaptive behaviors and caregiver strain

Atypical sensory processing occurs in up to 97% of children on the autism spectrum. Children who are on the autism spectrum also commonly demonstrate challenging behaviors, and their caregivers report increased levels of strain in daily life. The aim of this study was to explore four sensory processing features; seeking, avoiding, sensitivity, and registration, and their relationships with maladaptive behaviors in children with autism, as well as with caregiver strain. Participants comprised 75 children with autism aged 7–12 years (M = 7.81). Caregivers completed three questionnaire measures examining child sensory processing, maladaptive behaviors, and perceptions of caregiver strain. We found avoiding significantly associated with irritability. Avoiding also displayed the strongest relationship with global caregiver strain. Avoiding and seeking were strongly related to hyperactivity/noncompliance (components of maladaptive behavior). A multiple regression was performed to explore how atypical sensory processing features and maladaptive behaviors together predicted caregiver strain. Together, maladaptive behaviors and sensory features accounted for 58% of the variance in total caregiver strain. The only significant individual predictor of total caregiver strain was sensory avoiding, which uniquely accounted for 5.76% of the variation. The findings suggest that atypical sensory processing is associated with overall caregiver strain, above that explained by maladaptive behaviors. Implications for targeted support for the benefit of the child, parents and family unit are discussed.

Sensory-Adapted Dental Environment for the Treatment of Patients with Autism Spectrum Disorder

Purpose: The importance of dental care and oral hygiene is often underestimated in people with autism spectrum disorder (ASD). Comorbidity with dental anxiety is greater in ASD subjects who also show unusual reactions to sensory stimuli. The aim of our study was to assess the efficacy for a sensory-adapted environment and targeted methods in reducing anxiety and positively influencing cooperation in children with ASD during a dental examination or specific treatments. Material and methods: The sample consisted of 50 Italian children with a diagnosis of ASD (36 males and 14 females; aged 9–10 years) presenting with mild intellectual disability (ID) and verbal language skills. The subjects enrolled in the study had at least two decayed teeth and all were treated in two different dental environments: regular dental environment (RDE) and sensory-adapted dental environment (SADE). Results: 20% of the sample was successfully treated in RDE, while 68% of subjects were successfully treated in SADE. Conclusions: Results suggest that a sensory-adapted environment positively affects the therapeutic dental treatment in patients with ASD and reaffirm that sensory dysregulation in children with ASD is a crucial factor influencing the successful outcome of oral care.

Sex/gender differences in children with autism spectrum disorder: A brief overview on epidemiology, symptom profile, and neuroanatomy

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental conditions whose shared core features are impairments in social interaction and communication as well as restricted patterns of behavior, interests, and activities. The significant and consistent male preponderance in ASD prevalence has historically affected the scientific knowledge of autism in females as regards, inter alia, the clinical presentation, the genetic architecture, and the structural brain underpinnings. Indeed, females with ASD are under-investigated as samples recruited for clinical research typically reflect the strong male bias of the disorder. In the last years, the study of the various aspects of sex/gender (s/g) differences in ASD is gaining increased clinical and research interest resulting in a growing number of investigations on this topic. Here, I review and discuss evidence emerged from epidemiological, clinical, and neuroimaging studies in the last decade focusing on s/g differences in children with ASD. These studies are the prerequisites for the development of assessment and treatment practices which take into consideration s/g differences in ASD. Ultimately, a better understanding of s/g differences aims at improving healthcare for both ASD males and females.

Neural Markers of Auditory Response and Habituation in Phelan-McDermid Syndrome

Phelan-McDermid Syndrome (PMS) is a rare genetic disorder caused by deletion or sequence variation in the SHANK3 gene at terminal chromosome 22 that confers high likelihood of comorbid autism spectrum disorder (ASD). Whereas individuals with idiopathic ASD (iASD) can demonstrate diverse patterns of sensory differences, PMS is mainly characterized by sensory hyporesponsiveness. This study used electrophysiology and a passive auditory habituation paradigm to test for neural markers of hyporesponsiveness. EEG was recorded from 15 individuals with PMS, 15 with iASD, and 16 with neurotypical development (NT) while a series of four consecutive 1,000 Hz tones was repeatedly presented. We found intact N1, P2, and N2 event-related potentials (ERPs) and habituation to simple auditory stimuli, both in individuals with iASD and in those with PMS. Both iASD and PMS groups showed robust responses to the initial tone and decaying responses to each subsequent tone, at levels comparable to the NT control group. However, in PMS greater initial N1 amplitude and habituation were associated with auditory hypersensitivity, and P2 habituation correlated with ASD symptomatology. Additionally, further classification of the PMS cohort into genetic groupings revealed dissociation of initial P2 amplitude and habituation of N1 based on whether the deletions included additional genes beyond solely SHANK3 and those not thought to contribute to phenotype. These results provide preliminary insight into early auditory processing in PMS and suggest that while neural response and habituation is generally preserved in PMS, genotypic and phenotypic characteristics may drive some variability. These initial findings provide early evidence that the robust pattern of behavioral hyporesponsiveness in PMS may be due, at least in audition, to higher order factors.

Sex-related differences in clinical characteristics of children with ASD without ID: Results from the ELENA cohort

OBJECTIVE

The literature on sex related-clinical differences for children with autism spectrum disorder (ASD) is highly contradictory, whereas this topic has major clinical implications. We aimed to investigate sex-related clinical differences in children with ASD without intellectual disability (ID).

MATERIALS AND METHODS

We compared 319 boys and 65 girls with ASD without ID, aged from 2 to 12 years, recruited from a multiregional cohort on their clinical profiles based on the scores for the Vineland-II, the SRS-2, the ADOS calibrated severity score, sensory processing, aberrant behaviors, and comorbidity rates.

RESULTS

Our results confirm a high sex ratio of 4.9 males/females. Many similarities were found in the clinical profiles. However, we found that girls had higher SRS-2 total scores. In addition, there was a negative correlation between the SRS-2 total score and the intellectual quotient level (IQ) for girls only.

CONCLUSION

We confirm the higher rates of boys with ASD without ID. A comparison between the girls and boys showed them to have similar clinical profiles, except for the SRS- 2 total scores, which were higher among girls, suggesting more severe social impairment perceived by parents. Our findings that the cognitive level is related to ASD severity in girls should be taken into account during the diagnostic procedure in the clinical interpretation of gold-standard measures of ASD, and additional clinical observations are necessary.

CLINICAL TRIAL REGISTRATION

[ClinicalTrials.gov], identifier [NCT02625116s].