Emerging signs of autism spectrum disorder in infancy: Putative neural substrate

Predictive validity of the Standardized Infant NeuroDevelopmental Assessment (SINDA) to identify 4-5 year-old children at risk of developmental delay in a low-risk sample

BACKGROUND

Early detection of developmental problems is important as it allows for early intervention. Previous studies, in high-risk infants, found high predictive values of atypical scores on the Standardized Infant NeuroDevelopmental Assessment (SINDA) for later neurodevelopmental disorders (i.e., cerebral palsy, intellectual disability).

AIMS

The present study explored SINDA's predictive values to identify risk of developmental delay at 4-5 years.

STUDY DESIGN

Cohort study.

SUBJECTS

786 low-risk Dutch children (367 boys; median gestational age: 40 (27-42) weeks; mean birth weight: 3455 (SD 577) grams).

OUTCOME MEASURES

The SINDA was assessed at 2-12 months and risk of developmental delay was assessed using the Ages and Stages Questionnaire (ASQ) at 4-5 years. SINDA's predictive values were determined for five ASQ domains and the total ASQ score for children at risk of marked (all ASQ domains deviant) and any (one or more ASQ domains deviant) developmental delay.

RESULTS

Presence of one atypical SINDA scale score showed low to moderate sensitivities (12-88 %, depending on the SINDA scale and ASQ domain involved), moderate to high specificities (66-94 %), low positive predictive values (PPVs; 3-16 %), and high negative predictive values (NPVs; 95-100 %) for children at risk of marked and any developmental. Presence of multiple atypical SINDA scale scores predicted deviant ASQ domains slightly better (sensitivities = 11-62 %, specificities = 90-98 %, PPVs = 6-30 %, and NPVs = 95-100 %).

CONCLUSIONS

In low-risk infants, SINDA's predictive value is low for detecting children at risk of marked and any developmental delay at 4-5 years, as reflected by the low sensitivities. One of the explanations is the relatively low prevalence of developmental delay in low-risk populations. This might have consequences for the application of the SINDA in general healthcare settings (e.g. child health clinics), but further studies are needed to draw this conclusion.

Metabotropic signaling within somatostatin interneurons controls transient thalamocortical inputs during development

During brain development, neural circuits undergo major activity-dependent restructuring. Circuit wiring mainly occurs through synaptic strengthening following the Hebbian "fire together, wire together" precept. However, select connections, essential for circuit development, are transient. They are effectively connected early in development, but strongly diminish during maturation. The mechanisms by which transient connectivity recedes are unknown. To investigate this process, we characterize transient thalamocortical inputs, which depress onto somatostatin inhibitory interneurons during development, by employing optogenetics, chemogenetics, transcriptomics and CRISPR-based strategies in mice. We demonstrate that in contrast to typical activity-dependent mechanisms, transient thalamocortical connectivity onto somatostatin interneurons is non-canonical and involves metabotropic signaling. Specifically, metabotropic-mediated transcription, of guidance molecules in particular, supports the elimination of this connectivity. Remarkably, we found that this process impacts the development of normal exploratory behaviors of adult mice.

Alterations in Preterm Brain Development: Relation to Developmental Assessment and Prediction

Infants born extremely preterm are at risk for compromised cognitive and motor outcome. There are various possibilities as to why this occurs. The "two-hit" hypothesis consists of interrelated developmental disruptions and insults. Both specifically affect the transient subplate neuronal layer (SNL) and the early development of brain circuitry. The SNL, analogous to a switchboard, is critical in connecting cortical and lower brain centers and is highly susceptible to disruptions and insults, producing dysfunctional neural networks. Damage to the SNL provides the putative link between atypical early brain development and later cognitive and academic function that require complex neural circuitry. This, in turn, has major ramifications for developmental assessment and prediction. KEY POINTS: · Preterm brains are highly susceptible to disruptions and insults, this being the two-hit hypothesis.. · There is a variation in which low-grade stressors "sensitize" the infant increasing susceptibility to a second stressor-causing brain damage.. · Subplate neuronal layer damage compromises outcome by interfering with thalamocortical connections.. · Combining neuroimaging and developmental testing is the best way to gain insight into these processes.. · Atypical early brain development may not be evident until the network is mature and challenged..

Metabotropic signaling within somatostatin interneurons controls transient thalamocortical inputs during development

During brain development, neural circuits undergo major activity-dependent restructuring. Circuit wiring mainly occurs through synaptic strengthening following the Hebbian "fire together, wire together" precept. However, select connections, essential for circuit development, are transient. They are effectively connected early in development, but strongly diminish during maturation. The mechanisms by which transient connectivity recedes are unknown. To investigate this process, we characterize transient thalamocortical inputs, which depress onto somatostatin inhibitory interneurons during development, by employing optogenetics, chemogenetics, transcriptomics and CRISPR-based strategies. We demonstrate that in contrast to typical activity-dependent mechanisms, transient thalamocortical connectivity onto somatostatin interneurons is non-canonical and involves metabotropic signaling. Specifically, metabotropic-mediated transcription, of guidance molecules in particular, supports the elimination of this connectivity. Remarkably, we found that this developmental process impacts the development of normal exploratory behaviors of adult mice.

Predictive value of the General Movements Assessment and Standardized Infant NeuroDevelopmental Assessment in infants at high risk of neurodevelopmental disorders

AIM

To compare the predictive values of the General Movements Assessment (GMA) and the Standardized Infant NeuroDevelopmental Assessment (SINDA) neurological scale for atypical neurodevelopmental outcome in 3-month-old at-risk infants.

METHOD

A total of 109 infants (gestational age 30 weeks; range: 24-41; 52 males) attending a non-academic outpatient clinic were assessed with the GMA and the SINDA at 3 (2-4) months corrected age. The GMA pays attention to the complexity of general movements and presence of fidgety movements. Atypical neurodevelopmental outcome at 24 months corrected age (and older) implied cerebral palsy (CP) or a Bayley Mental Development Index or Bayley Psychomotor Development Index lower than 70.

RESULTS

At 24 months corrected (and older) age, 16 children had an atypical outcome, including 14 children with CP. Regarding markedly reduced general movement complexity in combination with absent or sporadic fidgety movements, the GMA predicted an atypical outcome with specificity, positive, and negative predictive values greater than 0.900, and sensitivity of 0.687 (95% confidence interval [CI] = 0.460-0.915). SINDA predicted an atypical outcome with sensitivity, specificity, and negative predictive value greater than 0.900 and a positive predictive value of 0.652 (95% CI = 0.457-0.847). Regarding absent fidgety movements only or markedly reduced general movement complexity, the GMA predicted the outcome less well than both general movement criteria.

INTERPRETATION

The SINDA and GMA both predict neurodevelopmental outcome well, but SINDA is easier to learn than the GMA; being a non-video-based assessment, it allows caregiver feedback during the consultation whereas the GMA usually does not.

Cranio-Facial Characteristics in Autism Spectrum Disorder: A Scoping Review

Autism spectrum disorders (ASD) consist of a complex group of neurodevelopmental disorders characterised by qualitative impairments of social interactions, communication abilities, and a limited, stereotyped, and repetitive selection of interests and activities. In light of the imperative to identify a possible biomarker for ASD, it has been determined that craniofacial anomalies serve as significant risk factors for neurodevelopmental disorders. The aim of this scoping review is to deepen the knowledge of the scientific literature related to cranio-facial characteristics in individuals with ASD, with a particular focus on recent research advancements. The review was performed by employing the search strings (("Autism Spectrum Disorder" OR autism OR ASD OR "Autism Spectrum") AND ("facial morphology" OR "facial phenotype")) on the databases PubMed/MEDLINE, Scopus, and ERIC as of March 9, 2023. The review comprised seven studies whose findings were obtained through quantitative analysis of Euclidean distances between anatomical landmarks. The examination of facial abnormalities represents a possible reliable diagnostic biomarker that could aid in the timely identification of ASD. Phenotypic characteristics that may serve as predictive indicators of the severity of autistic symptoms can be observed in certain individuals with ASD by applying anthropometric and instrumental measurements. The presence of a phenotype characterised by an increased intercanthal distance and a reduced facial midline height appears to be associated with a higher degree of severity in autistic symptoms. In addition, it is worth noting that facial asymmetry and facial masculinity can be considered reliable indicators for predicting a more severe manifestation of symptoms.

Once upon a Time Oral Microbiota: A Cinderella or a Protagonist in Autism Spectrum Disorder?

Autism spectrum disorder (ASD) is a neurodevelopmental disorder evolving over the lifetime of individuals. The oral and gut microbial ecosystems are closely connected to each other and the brain and are potentially involved in neurodevelopmental diseases. This narrative review aims to identify all the available evidence emerging from observational studies focused on the role of the oral microbiome in ASD. A literature search was conducted using PubMed and the Cochrane Library for relevant studies published over the last ten years. Overall, in autistic children, the oral microbiota is marked by the abundance of several microbial species belonging to the Proteobacteria phylum and by the depletion of species belonging to the Bacteroidetes phylum. In mouse models, the oral microbiota is marked by the abundance of the Bacteroidetes phylum. Oral dysbiosis in ASD induces changes in the human metabolome, with the overexpression of metabolites closely related to the pathogenesis of ASD, such as acetate, propionate, and indoles, together with the underexpression of butyrate, confirming the central role of tryptophan metabolism. The analysis of the literature evidences the close relationship between oral dysbiosis and autistic core symptoms; the rebuilding of the oral and gut ecosystems by probiotics may significantly contribute to mitigating the severity of ASD symptoms.

Possible disrupted biological movement processing in Developmental Coordination Disorder

AIM

There is emerging evidence that the Mirror Neuron System (MNS) might contribute to the motor learning difficulties characteristic of Developmental Coordination Disorder (DCD). This study aimed to identify whether MNS activity differed between children with and without DCD during action observation, action execution and during a non-action baseline.

METHODS

Electroencephalography (EEG) was used to measure mu rhythm (a proxy for MNS activation) in 8-12-year-old children either with (n = 20) or without (n = 19) a diagnosis of DCD. The mu rhythm was recorded at rest and during five experimental conditions: (1) observation of gross motor and (2) fine motor actions; (3) execution of gross motor and (4) fine motor actions; and (5) non-biological movement. To address whether potential co-occurring traits of other neurodevelopmental conditions were associated with differences in mu rhythm, parents reported their child's attention and social communication skills. Mixed and repeated measure ANOVAs were conducted to examine differences in mu desynchronization and mu power respectively.

RESULTS

The non-DCD group showed greater mu rhythm desynchronization than children with DCD (i.e., more MNS activity), with both groups demonstrating increasing desynchronization from observation of fine actions to execution of gross actions. However, we also found that the children with DCD had less mu power during the non-biological movement condition than the non-DCD children, although mu power did not differ between groups during the resting condition. Correlations between mu desynchronization and children's attention and motor skills showed that poorer attention and motor abilities were associated with reduced MNS activity.

CONCLUSION

Compared to children without DCD, the MNS in children with DCD did not distinguish between biological and non-biological movement. It is possible that the reduced specificity of the MNS in children with DCD is an underlying factor in the motor impairments observed in the disorder. The differential MNS activity could reflect broader atypical activity in perceptual networks that feed into the MNS in DCD.

Sensory Processing in Children and Adolescents with Neurofibromatosis Type 1

Despite the evidence of elevated autistic behaviors and co-occurring neurodevelopmental difficulties in many children with neurofibromatosis type 1 (NF1), we have a limited understanding of the sensory processing challenges that may occur with the condition. This study examined the sensory profile of children and adolescents with NF1 and investigated the relationships between the sensory profiles and patient characteristics and neuropsychological functioning. The parent/caregivers of 152 children with NF1 and 96 typically developing children completed the Sensory Profile 2 (SP2), along with standardized questionnaires assessing autistic behaviors, ADHD symptoms, internalizing symptoms, adaptive functioning, and social skills. Intellectual functioning was also assessed. The SP2 data indicated elevated sensory processing problems in children with NF1 compared to typically developing children. Over 40% of children with NF1 displayed differences in sensory registration (missing sensory input) and were unusually sensitive to and unusually avoidant of sensory stimuli. Sixty percent of children with NF1 displayed difficulties in one or more sensory modalities. Elevated autistic behaviors and ADHD symptoms were associated with more severe sensory processing difficulties. This first detailed assessment of sensory processing, alongside other clinical features, in a relatively large cohort of children and adolescents with NF1 demonstrates the relationships between sensory processing differences and adaptive skills and behavior, as well as psychological well-being. Our characterization of the sensory profile within a genetic syndrome may help facilitate more targeted interventions to support overall functioning.

Changing subplate circuits: Early activity dependent circuit plasticity

Early neural activity in the developing sensory system comprises spontaneous bursts of patterned activity, which is fundamental for sculpting and refinement of immature cortical connections. The crude early connections that are initially refined by spontaneous activity, are further elaborated by sensory-driven activity from the periphery such that orderly and mature connections are established for the proper functioning of the cortices. Subplate neurons (SPNs) are one of the first-born mature neurons that are transiently present during early development, the period of heightened activity-dependent plasticity. SPNs are well integrated within the developing sensory cortices. Their structural and functional properties such as relative mature intrinsic membrane properties, heightened connectivity via chemical and electrical synapses, robust activation by neuromodulatory inputs-place them in an ideal position to serve as crucial elements in monitoring and regulating spontaneous endogenous network activity. Moreover, SPNs are the earliest substrates to receive early sensory-driven activity from the periphery and are involved in its modulation, amplification, and transmission before the maturation of the direct adult-like thalamocortical connectivity. Consequently, SPNs are vulnerable to sensory manipulations in the periphery. A broad range of early sensory deprivations alters SPN circuit organization and functions that might be associated with long term neurodevelopmental and psychiatric disorders. Here we provide a comprehensive overview of SPN function in activity-dependent development during early life and integrate recent findings on the impact of early sensory deprivation on SPNs that could eventually lead to neurodevelopmental disorders.

Combination of machine learning-based bulk and single-cell genomics reveals necroptosis-related molecular subtypes and immunological features in autism spectrum disorder

Background

Necroptosis is a novel form of controlled cell death that contributes to the progression of various illnesses. Nonetheless, the function and significance of necroptosis in autism spectrum disorders (ASD) remain unknown and require further investigation.

Methods

We utilized single-nucleus RNA sequencing (snRNA-seq) data to assess the expression patterns of necroptosis in children with autism spectrum disorder (ASD) based on 159 necroptosis-related genes. We identified differentially expressed NRGs and used an unsupervised clustering approach to divide ASD children into distinct molecular subgroups. We also evaluated immunological infiltrations and immune checkpoints using the CIBERSORT algorithm. Characteristic NRGs, identified by the LASSO, RF, and SVM-RFE algorithms, were utilized to construct a risk model. Moreover, functional enrichment, immune infiltration, and CMap analysis were further explored. Additionally, external validation was performed using RT-PCR analysis.

Results

Both snRNA-seq and bulk transcriptome data demonstrated a greater necroptosis score in ASD children. Among these cell subtypes, excitatory neurons, inhibitory neurons, and endothelials displayed the highest activity of necroptosis. Children with ASD were categorized into two subtypes of necroptosis, and subtype2 exhibited higher immune activity. Four characteristic NRGs (TICAM1, CASP1, CAPN1, and CHMP4A) identified using three machine learning algorithms could predict the onset of ASD. Nomograms, calibration curves, and decision curve analysis (DCA) based on 3-NRG have been shown to have clinical benefit in children with ASD. Furthermore, necroptosis-based riskScore was found to be positively associated with immune activation. Finally, RT-PCR demonstrated differentially expressed of these four NRGs in human peripheral blood samples.

Conclusion

A comprehensive identification of necroptosis may shed light on the underlying pathogenic process driving ASD onset. The classification of necroptosis subtypes and construction of a necroptosis-related risk model may yield significant insights for the individualized treatment of children with ASD.

The developing brain: Challenges and opportunities to promote school readiness in young children at risk of neurodevelopmental disorders in low- and middle-income countries

This paper discusses possibilities for early detection and early intervention in infants with or at increased risk of neurodevelopmental disorders in low- and middle-income countries (LMICs). The brain's high rate of developmental activity in the early years post-term challenges early detection. It also offers opportunities for early intervention and facilitation of school readiness. The paper proposes that in the first year post-term two early detection options are feasible for LMICs: (a) caregiver screening questionnaires that carry little costs but predict neurodevelopmental disorders only moderately well; (b) the Hammersmith Infant Neurological Examination and Standardized Infant NeuroDevelopmental Assessment (SINDA) which are easy tools that predict neurodisability well but require assessment by health professionals. The young brain's neuroplasticity offers great opportunities for early intervention. Ample evidence indicates that families play a critical role in early intervention of infants at increased risk of neurodevelopmental disorders. Other interventional key elements are responsive parenting and stimulation of infant development. The intervention's composition and delivery mode depend on the infant's risk profile. For instance, in infants with moderately increased risk (e.g., preterm infants) lay community health workers may provide major parts of intervention, whereas in children with neurodisability (e.g., cerebral palsy) health professionals play a larger role.