Atypical longitudinal development of speech‐evoked auditory brainstem response in preschool children with autism spectrum disorders

Using Pivotal Response Treatment to Improve Language Functions of Autistic Children in Special Schools: A Randomized Controlled Trial

Language difficulties exert profound negative effects on the cognitive and social development of autistic children. Pivotal Response Treatment (PRT) is a promising intervention for improving social communication in autistic children, but there is a lack of a comprehensive examination of language functions. This study aimed to investigate the effectiveness of PRT in promoting the primary language functions (requesting, labeling, repeating, responding) defined by (Skinner, B. F. (1957). Verbal behavior. Martino Publishing.) theory of verbal behavior in autistic children. Thirty autistic children were randomly divided into the PRT group (Mage = 6.20, SDage = 1.21) and control group (Mage = 6.07, SDage = 1.49). The PRT group were provided with an 8-week training of the PRT motivation component in addition to treatment as usual (TAU) in their schools, whereas the control group only received TAU. Parents of the PRT group were also trained to practice the PRT motivation procedures at home. The PRT group demonstrated greater improvements in all four measured language functions compared to the control group. The improvement in language functions in the PRT group was generalized and maintained at the follow-up assessment. In addition, the PRT intervention enhanced untargeted social and communicative functioning, cognition, motor skills, imitation, and adaptive behaviors in the autistic children. In conclusion, language intervention using the motivation component of PRT is effective in promoting language functions as well as widespread untargeted cognitive and social functions in autistic children.

Incidence of Otolaryngological Manifestations in Individuals with Autism Spectrum Disorder: A Special Focus on Auditory Disorders

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by stereotyped and repetitive behavior patterns. In addition to neurological and behavioral problems, individuals with ASD commonly experience otolaryngological comorbidities. Individuals with ASD often have auditory disorders including hearing loss and auditory processing disorders such as central auditory processing disorder (CAPD), as well as both chronic and recurrent otitis media. These challenges negatively impact a person's ability to effectively communicate and may further impact their neurological functioning, particularly when not appropriately treated. Individuals diagnosed with ASD also have difficulty sleeping which contributes to increased irritability and may further aggravate the core behavioral symptoms of autism. The individuals with ASD also have a higher rate of sinusitis which contributes to the worsening of the autism behavior phenotype. The high prevalence of otolaryngological comorbidities in individuals with ASD warrants a better collaboration between their various healthcare providers and otolaryngologists with expertise in auditory, sleep, and sinus disorders in pursuit of improving the quality of life of affected individuals and their families/caregivers.

A Preliminary Study Characterizing Subcortical and Cortical Auditory Processing and Their Relation to Autistic Traits and Sensory Features

This study characterizes the subcortical auditory brainstem response (speech-ABR) and cortical auditory processing (P1 and Mismatch Negativity; MMN) to speech sounds and their relationship to autistic traits and sensory features within the same group of autistic children (n = 10) matched on age and non-verbal IQ to their typically developing (TD) peers (n = 21). No speech-ABR differences were noted, but autistic individuals had larger P1 and faster MMN responses. Correlations revealed that larger P1 amplitudes and MMN responses were associated with greater autistic traits and more sensory features. These findings highlight the complexity of the auditory system and its relationships to behaviours in autism, while also emphasizing the importance of measurement and developmental matching.

Autism Spectrum Disorder and auditory sensory alterations: a systematic review on the integrity of cognitive and neuronal functions related to auditory processing

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition with a wide spectrum of symptoms, mainly characterized by social, communication, and cognitive impairments. Latest diagnostic criteria according to DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, 2013) now include sensory issues among the four restricted/repetitive behavior features defined as "hyper- or hypo-reactivity to sensory input or unusual interest in sensory aspects of environment". Here, we review auditory sensory alterations in patients with ASD. Considering the updated diagnostic criteria for ASD, we examined research evidence (2015-2022) of the integrity of the cognitive function in auditory-related tasks, the integrity of the peripheral auditory system, and the integrity of the central nervous system in patients diagnosed with ASD. Taking into account the different approaches and experimental study designs, we reappraise the knowledge on auditory sensory alterations and reflect on how these might be linked with behavior symptomatology in ASD.

Speech auditory brainstem response in audiological practice: a systematic review

BACKGROUND

Speech-ABR is an auditory brainstem response that evaluates the integrity of the temporal and spectral coding of speech in the upper levels of the brainstem. It reflects the acoustic properties of the stimulus used and consists of seven major waves. Waves V and A represent the onset of the response; wave C transition region; D, E, and F waves periodic region (frequency following response); and wave O reflects the offset of the response.

PURPOSE

The aim of this study is to evaluate the clinical availability of the speech-ABR procedure through a literature review.

METHODS

Literature search was conducted in Pubmed, Google Scholar, Scopus and Science Direct databases. Clinical studies of the last 15 years have been included in this review and 60 articles have been reviewed.

RESULTS

As a result of the articles reviewed, it was seen that most of the studies on speech ABR were conducted with children and young people and generally focused on latency analysis measurements. Most used stimulus is the /da/ syllable.

CONCLUSIONS

Speech ABR can objectively measure the auditory cues important for speech recognition and has many clinical applications. It can be used as a biomarker for auditory processing disorders, learning disorders, dyslexia, otitis media, hearing loss, language disorders and phonological disorders. S-ABR is an effective procedure that can be used in speech and language evaluations in people with hearing aids or cochlear implant. It may also be of benefit to the aging auditory system's ability to encode temporal cues.

The viability of the frequency following response characteristics for use as biomarkers of cognitive therapeutics in schizophrenia

Deficits in early auditory information processing contribute to cognitive and psychosocial disability; this has prompted development of interventions that target low-level auditory processing, which may alleviate these disabilities. The frequency following response (FFR) is a constellation of event-related potential and frequency characteristics that reflect the processing of acoustic stimuli at the level of the brainstem and ascending portions of the auditory pathway. While FFR is a promising candidate biomarker of response to auditory-based cognitive training interventions, the psychometric properties of FFR in schizophrenia patients have not been studied. Here we assessed the psychometric reliability and magnitude of group differences across 18 different FFR parameters to determine which of these parameters demonstrate adequate internal consistency. Electroencephalography from 40 schizophrenia patients and 40 nonpsychiatric comparison subjects was recorded during rapid presentation of an auditory speech stimulus (6000 trials). Patients showed normal response amplitudes but longer latencies for most FFR peaks and lower signal-to-noise ratios (SNRs) than healthy subjects. Analysis of amplitude and latency estimates of peaks, however, indicated a need for a substantial increase in task length to obtain internal consistency estimates above 0.80. In contrast, excellent internal consistency (>0.95) was shown for FFR sustained responses. Only SNR scores reflecting the FFR sustained response yielded significant group differences and excellent internal consistency, suggesting that this measure is a viable candidate for use in clinical treatment studies. The present study highlights the use of internal consistency estimates to select FFR characteristics for use in future intervention studies interested in individual differences among patients.

A Systematic Review of Brainstem Contributions to Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects one in 66 children in Canada. The contributions of changes in the cortex and cerebellum to autism have been studied for decades. However, our understanding of brainstem contributions has only started to emerge more recently. Disruptions of sensory processing, startle response, sensory filtering, sensorimotor gating, multisensory integration and sleep are all features of ASD and are processes in which the brainstem is involved. In addition, preliminary research into brainstem contribution emphasizes the importance of the developmental timeline rather than just the mature brainstem. Therefore, the purpose of this systematic review is to compile histological, behavioral, neuroimaging, and electrophysiological evidence from human and animal studies about brainstem contributions and their functional implications in autism. Moreover, due to the developmental nature of autism, the review pays attention to the atypical brainstem development and compares findings based on age. Overall, there is evidence of an important role of brainstem disruptions in ASD, but there is still the need to examine the brainstem across the life span, from infancy to adulthood which could lead the way for early diagnosis and possibly treatment of ASD.

The Brainstem-Informed Autism Framework: Early Life Neurobehavioral Markers

Autism spectrum disorders (ASD) have long-term implications on functioning at multiple levels. In this perspective, we offer a brainstem-informed autism framework (BIAF) that traces the protracted neurobehavioral manifestations of ASD to early life brainstem dysfunctions. Early life brainstem-mediated markers involving functions of autonomic/arousal regulation, sleep-wake homeostasis, and sensorimotor integration are delineated. Their possible contributions to the early identification of susceptible infants are discussed. We suggest that the BIAF expands our multidimensional understanding of ASD by focusing on the early involvement of brainstem systems. Importantly, we propose an integrated BIAF screener that brings about the prospect of a sensitive and reliable early life diagnostic scheme for weighing the risk for ASD. The BIAF screener could provide clinicians substantial gains in the future and may carve customized interventions long before the current DSM ASD phenotype is manifested using dyadic co-regulation of brainstem-informed autism markers.

Central Auditory and Vestibular Dysfunction Are Key Features of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by repetitive behaviors, poor social skills, and difficulties with communication. Beyond these core signs and symptoms, the majority of subjects with ASD have some degree of auditory and vestibular dysfunction. Dysfunction in these sensory modalities is significant as normal cognitive development depends on an accurate representation of our environment. The hearing difficulties in ASD range from deafness to hypersensitivity and subjects with ASD have abnormal sound-evoked brainstem reflexes and brainstem auditory evoked potentials. Vestibular dysfunction in ASD includes postural instability, gait dysfunction, and impaired gaze. Untreated vestibular dysfunction in children can lead to delayed milestones such as sitting and walking and poor motor coordination later in life. Histopathological studies have revealed that subjects with ASD have significantly fewer neurons in the auditory hindbrain and surviving neurons are smaller and dysmorphic. These findings are consistent with auditory dysfunction. Further, the cerebellum was one of the first brain structures implicated in ASD and studies have revealed loss of Purkinje cells and the presence of ectopic neurons. Together, these studies suggest that normal auditory and vestibular function play major roles in the development of language and social abilities, and dysfunction in these systems may contribute to the core symptoms of ASD. Further, auditory and vestibular dysfunction in children may be overlooked or attributed to other neurodevelopmental disorders. Herein we review the literature on auditory and vestibular dysfunction in ASD. Based on these results we developed a brainstem model of central auditory and vestibular dysfunction in ASD and propose that simple, non-invasive but quantitative testing of hearing and vestibular function be added to newborn screening protocols.

Frequency-Following Response in Newborns and Infants: A Systematic Review of Acquisition Parameters

Purpose The purpose of this study is to characterize parameters used for frequency-following response (FFR) acquisition in children up to 24 months of age through a systematic review. Method The study was registered in PROSPERO and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses' recommendations. Search was performed in six databases (LILACS, LIVIVO, PsycINFO, PubMed, Scopus, and Web of Science) and gray literature (Google Scholar, OpenGrey, ProQuest)as well as via manual searches in bibliographic references. Observational studies using speech stimuli to elicit the FFR in infants with normal hearing on the age range from 0 until 24 months were included. No restrictions regarding language and year of publication were applied. Risk of bias was assessed with the Joanna Briggs Institute Critical Appraisal Checklist. Data on stimulus, presentation rate, time window for analysis, number of sweeps, artifact rejection, online filters, stimulated ear, and examination condition were extracted. Results Four hundred fifty-nine studies were identified. After removing duplicates and reading titles and abstracts, 15 articles were included. Seven studies were classified as low risk of bias, seven as moderate risk, and one as high risk. Conclusions There is a consensus in the use of some acquisition parameters of the FFR with speech stimulus, such as the vertical mounting, the use of alternating polarity, a sampling rate of 20000 Hz, and the /da/ synthesized syllable of 40 ms in duration as the preferred stimulus. Although these parameters show some consensus, the results disclosed lack of a single established protocol for FFR acquisition with speech stimulus in infants in the investigated age range.

Dysfunction of the Auditory Brainstem as a Neurophysiology Subtype of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is very heterogeneous, particularly in language. Studies have suggested that language impairment is linked to auditory-brainstem dysfunction in ASD. However, not all ASD children have these deficits, which suggests potential subtypes of ASD. We classified ASD children into two subtypes according to their speech-evoked auditory brainstem response (speech-ABR) and explored the neural substrates for possible subtypes. Twenty-nine children with ASD and 25 typically developing (TD) peers were enrolled to undergo speech-ABR testing and structural magnetic resonance imaging (sMRI). There were significant differences between the ASD group and TD group in surface area, cortical volume and cortical thickness. According to speech-ABR results, ASD participants were divided into the ASD-typical (ASD-T) group and ASD-atypical (ASD-A) group. Compared with the ASD-T group, the ASD-A group had a lower score in language of the Gesell Developmental Diagnosis Scale (GDDS), increased left rostral middle frontal gyrus (lRMFG) area and decreased local gyrification index of the right superior temporal gyrus. GDDS-language and surface area of lRMFG were correlated to the wave-A amplitude in ASD. Surface area of lRMFG had an indirect effect on language performance via alteration of the wave-V amplitude. Thus, cortical deficits may impair language ability in children with ASD by causing subcortical dysfunction at preschool age. These evidences support dysfunction of the auditory brainstem as a potential subtype of ASD. Besides, this subtype-based method may be useful for various clinical applications.

Study of the brainstem auditory evoked potential with speech stimulus in the pediatric population with and without oral language disorders: a systematic review

Introduction

Objective

Methods

Result

Conclusion

Altered brain-wide auditory networks in a zebrafish model of fragile X syndrome

BACKGROUND

Loss or disrupted expression of the FMR1 gene causes fragile X syndrome (FXS), the most common monogenetic form of autism in humans. Although disruptions in sensory processing are core traits of FXS and autism, the neural underpinnings of these phenotypes are poorly understood. Using calcium imaging to record from the entire brain at cellular resolution, we investigated neuronal responses to visual and auditory stimuli in larval zebrafish, using fmr1 mutants to model FXS. The purpose of this study was to model the alterations of sensory networks, brain-wide and at cellular resolution, that underlie the sensory aspects of FXS and autism.

RESULTS

Combining functional analyses with the neurons' anatomical positions, we found that fmr1-/- animals have normal responses to visual motion. However, there were several alterations in the auditory processing of fmr1-/- animals. Auditory responses were more plentiful in hindbrain structures and in the thalamus. The thalamus, torus semicircularis, and tegmentum had clusters of neurons that responded more strongly to auditory stimuli in fmr1-/- animals. Functional connectivity networks showed more inter-regional connectivity at lower sound intensities (a - 3 to - 6 dB shift) in fmr1-/- larvae compared to wild type. Finally, the decoding capacities of specific components of the ascending auditory pathway were altered: the octavolateralis nucleus within the hindbrain had significantly stronger decoding of auditory amplitude while the telencephalon had weaker decoding in fmr1-/- mutants.

CONCLUSIONS

We demonstrated that fmr1-/- larvae are hypersensitive to sound, with a 3-6 dB shift in sensitivity, and identified four sub-cortical brain regions with more plentiful responses and/or greater response strengths to auditory stimuli. We also constructed an experimentally supported model of how auditory information may be processed brain-wide in fmr1-/- larvae. Our model suggests that the early ascending auditory pathway transmits more auditory information, with less filtering and modulation, in this model of FXS.

Auditory Processing Differences in Toddlers With Autism Spectrum Disorder

Purpose Auditory processing measures have been used in an attempt to understand the relationship between neurological mechanisms and autism spectrum disorder (ASD) symptomatology in school-age children. The focus of the current study was to understand neural auditory processing in 2- to 3-year-olds with ASD. Method Auditory processing measures (click auditory brainstem responses and speech-evoked frequency-following responses) were hypothesized to differ between typically developing children (n = 18) and children with ASD (n = 18). Auditory processing measures were hypothesized to relate to language development in children with ASD. Results The current study found limited differences in auditory processing measures between the two groups. No relationships were found between auditory processing measures and language development measures. Conclusions Future research is necessary to characterize auditory processing in toddlers with ASD. Longitudinal approaches should be considered when studying auditory processing in children with ASD in order to explore its developmental relationship with ASD symptomatology.

Analyzing the FFR: A tutorial for decoding the richness of auditory function

The frequency-following response, or FFR, is a neurophysiological response to sound that precisely reflects the ongoing dynamics of sound. It can be used to study the integrity and malleability of neural encoding of sound across the lifespan. Sound processing in the brain can be impaired with pathology and enhanced through expertise. The FFR can index linguistic deprivation, autism, concussion, and reading impairment, and can reflect the impact of enrichment with short-term training, bilingualism, and musicianship. Because of this vast potential, interest in the FFR has grown considerably in the decade since our first tutorial. Despite its widespread adoption, there remains a gap in the current knowledge of its analytical potential. This tutorial aims to bridge this gap. Using recording methods we have employed for the last 20 + years, we have explored many analysis strategies. In this tutorial, we review what we have learned and what we think constitutes the most effective ways of capturing what the FFR can tell us. The tutorial covers FFR components (timing, fundamental frequency, harmonics) and factors that influence FFR (stimulus polarity, response averaging, and stimulus presentation/recording jitter). The spotlight is on FFR analyses, including ways to analyze FFR timing (peaks, autocorrelation, phase consistency, cross-phaseogram), magnitude (RMS, SNR, FFT), and fidelity (stimulus-response correlations, response-to-response correlations and response consistency). The wealth of information contained within an FFR recording brings us closer to understanding how the brain reconstructs our sonic world.