Abnormal Auditory Brainstem Response Research Articles

A case of cerebellopontine angle meningioma presenting as neurovascular compression syndrome of the 8th cranial nerve

A 54-year-old female patient presented with paroxysmal tinnitus and vertigo for 2 years, which have repeatedly occurred while rotating her neck, and lasted about 10 seconds. An anticonvulsant medication was prescribed with a diagnosis of microvascular compression syndrome on the 8th cranial nerve and audiovestibular evaluation and magnetic resonance imaging (MRI) scan were appointed a week later. In her next visit, she reported the disappearance of paroxysmal audiovestibular symptoms after medication. In the left ear, canal paresis and abnormal auditory brainstem response were observed. In MRI, a large meningioma in the cerebellopontine angle in the vicinity of the internal auditory canal orifice was detected, that was surgically resected by a neurosurgeon. After surgical removal of the tumor, she reported continuous dizziness due to vestibular nerve injury, but the paroxysmal attack of tinnitus and vertigo disappeared without anticonvulsant medication. This case suggests that an imaging study is mandatory when diagnosing microvascular compression syndrome on the 8th cranial nerve.

Is Lead Exposure Still The Best Explanation For Beethoven’s Deafness?

Objectives: An article in Current Biology in March 2023 suggested that lead poisoning does not apply to Beethoven because the Hiller lock was found to be inauthentic. In addition, bone samples that contained high levels of lead have also been discovered to be inauthentic. This communication is a response to this as well as other challenges to the article in The Laryngoscope in 2013 about lead and the hearing loss of Ludwig van Beethoven. Methods: An in-depth review of these articles was accomplished to assess whether lead poisoning is still a viable theory for Beethoven’s hearing loss. Results: A substantial review of over 2000 cases in 2016 showed uniformly abnormal auditory brainstem responses with chronic lead poisoning that correlate well with the shrunken cochlear nerves found at Beethoven’s autopsy. An article published in 2017 postulated a new reason for Paget’s Disease, but has serious deficiencies. The current case of lead poisoning in The Laryngoscope in 2020 supports lead as a cause significant hearing loss. In 2022 a suggestion of congenital syphilis was found to lack substantial evidence. Although the article in Current Biology in March 2023 suggested that lead poisoning does not apply to Beethoven because the Hiller lock was found to be inauthentic, no authentic samples have ever been tested for lead. Therefore, this is a premature opinion. Conclusion: Future directions listed in the Current Biology article include testing for exposure to environmental causes of disease. We will therefore wait with great anticipation to the analyses of authentic hair samples. It may not be surprising that these will also show high levels of lead. If they do not, all of the suggested reasons for Beethoven’s hearing loss will have major problems, and we may never fulfill his wish to discover the etiology of his loss.

Preserved Auditory Steady State Response and Envelope-Following Response in Severe Brainstem Dysfunction Highlight the Need for Cross-Checking.

Commercially available auditory steady state response (ASSR) systems are widely used to obtain hearing thresholds in the pediatric population objectively. Children are often examined during natural or induced sleep so that the recorded ASSRs are of subcortical origin, the inferior colliculus being often designated as the main ASSR contributor in these conditions. This report presents data from a battery of auditory neurophysiological objective tests obtained in 3 cases of severe brainstem dysfunction in sleeping children. In addition to ASSRs, envelope-following response (EFR) recordings designed to distinguish peripheral (cochlear nerve) from central (brainstem) were recorded to document the effect of brainstem dysfunction on the two types of phase-locked responses. Results obtained in the 3 children with severe brainstem dysfunctions were compared with those of age-matched controls. The cases were identified as posterior fossa tumor, undiagnosed (UD), and Pelizaeus-Merzbacher-Like Disease. The standard audiological objective tests comprised tympanograms, distortion product otoacoustic emissions, click-evoked auditory brainstem responses (ABRs), and ASSRs. EFRs were recorded using horizontal (EFR-H) and vertical (EFR-V) channels and a stimulus phase rotation technique allowing isolation of the EFR waveforms in the time domain to obtain direct latency measurements. The brainstem dysfunctions of the 3 children were revealed as abnormal (weak, absent, or delayed) ABRs central waves with a normal wave I. In addition, they all presented a summating and cochlear microphonic potential in their ABRs, coupled with a normal wave I, which implies normal cochlear and cochlear nerve function. EFR-H and EFR-V waveforms were identified in the two cases in whom they were recorded. The EFR-Hs onset latencies, response durations, and phase-locking values did not differ from their respective age-matched control values, indicating normal cochlear nerve EFRs. In contrast, the EFR-V phase-locking value and onset latency varied from their control values. Both patients had abnormal but identifiable and significantly phase-locked brainstem EFRs, even in a case with severely distorted ABR central waves. ASSR objective audiograms were recorded in two cases. They showed normal or slightly elevated (explained by a slight transmission loss) thresholds that do not yield any clue about their brainstem dysfunction, revealing the method's lack of sensitivity to severe brainstem dysfunction. The present study, performed on 3 sleeping children with severe brainstem dysfunction but normal cochlear responses (cochlear microphonic potential, summating potential, and ABR wave I), revealed the differential sensitivity of three auditory electrophysiological techniques. Estimated thresholds obtained by standard ASSR recordings (cases UD and Pelizaeus-Merzbacher-Like Disease) provided no clue to the brainstem dysfunction clearly revealed by the click-evoked ABR. EFR recordings (cases posterior fossa tumor and UD) showed preserved central responses with abnormal latencies and low phase-locking values, whereas the peripheral EFR attributed to the cochlear nerve was normal. The one case (UD) for which the three techniques could be performed confirms this sensitivity gradient, emphasizing the need for applying the Cross-Check Principle by avoiding resorting to ASSR recording alone. The entirely normal EFR-H recordings observed in two cases further strengthen the hypothesis of its cochlear nerve origin in sleeping children.

Second nationwide survey of bilirubin encephalopathy in preterm infants in Japan

ObjectivesTo determine the clinical features of bilirubin encephalopathy in preterm infants (pBE) in Japan. MethodsWe performed a retrospective, nationwide questionnaire-based survey. The initial survey determined the number of children with pBE who were born after 2000. Using a structured questionnaire, the second survey clarified the clinical manifestations and characteristics of children with pBE, including demographic data, neurological symptoms, and MRI and auditory brainstem response (ABR) findings. ResultsThe initial survey identified 41 pBE infants from 18 institutions. After exclusion of patients included in previous studies, clinical information was collected from 30 patients (21 boys and 9 girls) during the secondary survey. The median gestational age was 26 weeks and the median birthweight was 846 g. Chronic lung disease and symptomatic patent ductus arteriosus were common neonatal complications. Head control was observed in 63% and functional gait in 17% of patients. Purposeful hand use was seen in 57% and verbal communication in 50% of patients. MRI showed T2 hyperintensities in the globus pallidus of 29 of 30 patients. ABR abnormalities were present in 11 of 15 patients. None of the variables were significantly different between the 2017 and 2021 surveys. ConclusionsThe pBE infants had severely impaired gross motor function and relatively preserved manual function and verbal communication. MRI and ABR findings aid in the diagnosis of pBE.

Abnormal auditory brainstem responses in an animal model of autism spectrum disorder

Auditory dysfunction is a common feature of autism spectrum disorder (ASD) and ranges from deafness to hypersensitivity. The auditory brainstem response (ABR) permits study of the amplitude and latency of synchronized electrical activity along the ascending auditory pathway in response to clicks and pure tone stimuli. Indeed, numerous studies have shown that subjects with ASD have ABR abnormalities. In utero exposure to the antiepileptic drug valproic acid (VPA) is associated with human cases of ASD and is used as an animal model of ASD. Previous studies have shown that VPA-exposed animals have significantly fewer neurons in the auditory brainstem and thalamus, reduced ascending projections to the auditory midbrain and thalamus and increased neuronal activation in response to pure tone stimuli. Accordingly, we hypothesized that VPA-exposed animals would have abnormal ABRs throughout their lifespans. We approached this hypothesis in two cohorts. First, we examined ABRs from both ears on postnatal day 22 (P22). Then, we examined monaural ABRs in animals at P28, 60, 120, 180, 240, 300 and 360. Our results suggest that at P22, VPA-exposed animals have elevated thresholds and increased peak latencies. However, by P60 these differences largely normalize with differences appearing only near hearing threshold. Additionally, our analysis revealed that maturation of ABR waves occurred at different trajectories in control and VPA-exposed animals. These results, together with our previous work, suggest that VPA exposure not only impacts total neuron number and connectivity, but also auditory evoked responses. Finally, our longitudinal analysis suggests that delayed maturation of auditory brainstem circuits may impact ABRs throughout the lifespan of the animal.

Auditory Brainstem Response: ABR

Intraoperative auditory brainstem response(ABR)monitoring has been established as a reliable method to evaluate cochlear function. Intraoperative ABR is mandatory in microvascular decompression for hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia. Cerebellopontine tumor with remaining effective hearing function also requires ABR monitoring during surgery to preserve hearing function. Prolonged latency and subsequent amplitude decrease in the ABR wave V predicts postoperative hearing impairment. Therefore, when alerted to an intraoperative ABR during surgery, the surgeon should release the cerebellar retraction stressing the cochlear nerve and wait for the abnormal ABR to recover.

Prevalence and Auditory Characteristics of Auditory Neuropathy Spectrum Disorder in Adult Population with Sensory Neural Hearing Loss: A Hospital Based Study in South India.

Auditory neuropathy spectrum disorder (ANSD) is a heterogenous group of disorder characterized by abnormalities in auditory brainstem responses (ABR) with preserved otoacoustic emissions and/or cochlear microphonics. The aim of the study is to estimate the prevalence and evaluate the audiological characteristics of ANSD in adult population with sensory neural hearing loss. A prospective study was conducted on the adult population (≥ 18 years) attending ENT outpatients clinic at Rajiv Gandhi Government General Hospital, Chennai. All patients reported to the department with auditory and vestibular symptoms underwent case history, otoscopic examination, and routine audiological evaluation (pure tone audiometry, speech audiometry and immittance audiometry). Patients with indications of ANSD in case history and routine audiological evaluation were further evaluated using distortion product otoacoustic emissions and ABR. A total of 8682 adult population was evaluated during the period of 2017 to 2018. Out of 8682 patients, 1343 (15.46%) of them had sensory neural hearing loss of varying degrees. Out of 1343 adults with sensory neural hearing loss, 24 (1.78%) adults were diagnosed as ANSD. The prevalence of ANSD in adult population with sensory neural hearing loss in our study is 1.32% per 1000 adults. The clinical characteristics of ANSD shows impairment in speech perception irrespective of degree of hearing loss, preserved cochlear functions and abnormal ABR. Hence ANSD is not a rare clinical finding in adults with sensory neural hearing loss, but its prevalence was estimated to be lower in Indian population. Often young females are affected causing significant impairment in speech perception and disability.

Auditory neuropathy spectrum disorder (ANSD): a distortion product otoacoustic emissions (DPOAEs) study

BackgroundAuditory neuropathy spectrum disorder (ANSD) is characterized by normal OHCs function as shown by intact cochlear microphonics (CMs) and/or otoacoustic emissions (OAEs); absent or grossly abnormal auditory brainstem responses (ABRs) and absent middle ear muscle reflexes. This study is designed to address whether the input/output function of distortion product OAEs (DPOAEs I/O) in ANSD patients is similar or different from normal hearing subjects. This work included 2 groups: control group (GI) composed of 20 normal hearing subjects and study group (GII) consisted of 20 patients with ANSD. All cases were subjected to basic audiological evaluation, DPOAEs I/O function recorded at four frequencies of 2f1-f2 and 5 intensity levels of L1 and L2.ResultsDPOAEs amplitudes were significantly higher in ANSD group when compared with control. The pattern of DPOAEs I/O function was different in ANSD and it was dependent on the frequency and intensity of the stimulus.ConclusionsDespite normal DPOAEs recordings in ANSD patients, their amplitudes and DP I/O function are different from that of normal hearing subjects. This finding suggested different OHC pattern of activity in ANSD patients.

Sudden sensorineural hearing loss as the initial symptom in patients with acoustic neuroma.

BackgroundPrevious studies have shown that patients with acoustic neuroma (AN) sometimes present with sudden sensorineural hearing loss (SSNHL) as an initial symptom. The purpose of this research was to investigate the clinical characteristics, diagnosis, and treatment of AN in patients initially diagnosed with SSNHL.Materials and methodsWe reviewed retrospectively the medical records of all patients who were treated as SSNHL initially and were later diagnosed with AN after undergoing magnetic resonance imaging (MRI) at our hospital between 2008 and 2021. Patient demographics, associated complaints (mostly tinnitus and vertigo), the severity of hearing loss, audiogram configurations, auditory brainstem response (ABR), and MRI examination were reviewed and analyzed. In addition, treatment outcomes and management protocols were also included in this study.ResultsA total of 10 (0.7%, 10/1,383) patients presented with SSNHL as the initial symptom and were diagnosed as AN by MRI finally. Of the 10 patients enrolled in this study, four were men and six were women. The average age at the time of diagnosis of SSNHL was 46.2 ± 13.16 years. These patients exhibited varying severity of hearing loss and a variety of audiogram configurations. All patients showed an abnormal ABR. According to the Koos grading standard, there were 5 grade I (intracanalicular [IAC]) tumors, 3 grade II tumors, and 2 grade III tumors. The treatment outcome revealed that 2 patients exhibited recovery of the average hearing of impaired frequency by more than 15 dB, and 6 patients showed no recovery. Furthermore, four patients were referred to undergo surgical treatment after being diagnosed with AN, 1 patient accepted stereotactic radiation therapy, and the remaining 5 patients were on a “wait and scan” strategy.ConclusionThe hearing loss of patients with AN presented with SSNHL may improve with drug treatment. Hearing recovery for SSNHL does not exclude the presence of AN, and all patients initially diagnosed with SSNHL should undergo MRI and ABR to prevent misdiagnosis and delays in potential treatment.

Diagnostic Validity of Auditory Brainstem Response for the Initial Screening of Vestibular Schwannoma.

Background and ObjectivesTo investigate the diagnostic validity of auditory brainstem response (ABR) in the screening of vestibular schwannoma (VS).Subjects and MethodsForty patients diagnosed with VS using magnetic resonance imaging who had undergone ABR before treatment between 2005 and 2015 were included. ABR results were considered positive when findings met at least one of the following criteria: 1) absent evoked response, 2) desynchronization of waves other than wave I, 3) interpeak latency (IPL) between waves I and III >2.5 ms, 4) IPL between waves I and V >4.4 ms, 5) wave V interaural latency difference >0.2 ms, and 6) interaural difference in IPL between waves I and V >0.2 ms.ResultsThe overall sensitivity of ABR was 85.0%. For tumors measuring <10 mm, the sensitivity of ABR was 66.7%, whereas it increased to 90.3% for tumors measuring >10 mm. The sensitivity of tumors confined to the internal acoustic canal was 73.3% compared with 100.0% for tumors confined to the cerebellopontine angle. In patients with serviceable hearing, the mean tumor size was 7.8±2.9 mm in patients with a normal ABR and 15.1±9.4 mm in patients with an abnormal ABR, indicating a significant difference (p<0.05).ConclusionsABR alone is insufficient for the screening of VS, bearing the risk of false-negative outcomes when examining small, intracanalicular tumors. However, ABR can be inexpensively applied for the screening of VS measuring >10 mm in patients with serviceable hearing, supporting the need for further active diagnostic and treatment modalities in clinical practice.

Assessment of cochlear electrophysiology in typically developing children and children with auditory processing disorder

ObjectiveChildren with auditory processing disorder (APD) are reported to have abnormal auditory brainstem responses (ABR) but little is understood about their cochlear integrity. Poor cochlear integrity can affect neural responses. In this study, cochlear and auditory brainstem integrity was investigated in children with APD. MethodTwenty children with APD, sixteen typically developing children and twenty adults participated in this study. Click evoked electrocochleography (ECochG) and ABRs were recorded from all the participants. Cochlear responses were analyzed using a) latency and amplitude of summating potential; action potential, b) transmission time between summating potential and action potential, c) summating potential/action potential amplitude ratio and d) action potential latency difference to condensation and rarefaction polarity. Amplitude in the ABR components was examined. ResultsChildren with APD showed similar cochlear function to the typically developing children. There were no significant differences in wave I amplitude between children with APD and typically developing children. However, wave V amplitude was significantly reduced in children with APD compared to typically developing children. ConclusionIn the absence of any functional differences in the cochlea, children with APD can show poor amplitude in the later components of the ABR. The ABR anomalies observed in children with APD arise due to poor neural processing, possibly after the first auditory synapse.

Why a Propofol Infusion Should Be the Anesthetic of Choice for Auditory Brainstem Response Testing in Children.

Auditory brainstem response (ABR) testing is considered to be relatively resistant to effects of volatile anesthetics. The impact of newer anesthetics on interpretability of ABR testing is unknown. This study compared sevoflurane versus propofol anesthesia on qualitative interpretability of ABR click-testing in children. This prospective double-blind crossover study enrolled children (≤18 years old) receiving general anesthesia for elective ABR testing. All subjects received both sevoflurane and propofol anesthesias in the same ABR testing session. Deidentified ABR data were reviewed by 5 audiologists (blinded to anesthetic and patient) to determine threshold levels for hearing loss. The primary outcome was qualitative interpretability (false positive) of ABR click-testing. Each patient was tested at 4 different intensities in each ear: generating 624 records under each anesthetic, for a total of 1248 records. A few patients were tested at 5 different intensities in a single ear accounting for the additional 11 records, yielding 1259 records. Under sevoflurane anesthesia, 21 of the same patients (37 ears) were identified with abnormal ABR levels consistent with hearing loss (one or both ears). The probability of a patient being diagnosed with hearing "loss" in one or both ears was significantly less with propofol versus sevoflurane anesthesia (mid P =.0312). If patients with bilateral loss are compared, the mid P value is 0.0098. The effect size based on patients was medium to large, with a minimum value of Cohen w = 0.320. Sevoflurane produced more false positives for hearing loss and suggested more severe hearing loss than propofol. False-positive ABR tests, produced by certain anesthetic agents, can have significant life-long impact and negative psychosocial and developmental implications. Use of the intravenous anesthetic propofol is superior to sevoflurane for ABR testing in children.

Mitochondrial encephalomyopathy involves ophthalmology otorhinolaryngology neurology and their clinical features

Objective:This study aimed to provide better understanding of the otolaryngologic features, combined with ophthalmologic and neurologic characteristics in mitochondrial encephalomyopathy（MEM）, and to help ENT and auditory practitioner making correct diagnosis as well. Methods:Twenty-eight patients with MEM were enrolled between September 2001 and January 2020. Information about family histories and clinical symptoms was retrospectively analyzed. All patients underwent otorhinolaryngological, ophthalmological and neurological examinations, including: pure-tone audiometry, acoustic immittance（AI）, distortion-product otoacoustic emissions（DPOAE）, auditory brainstem response（ABR）, cochlear micropotential（CM）, speech discrimination score（SDS）, electroneurography（ENoG）, computed tomography（CT） of the temporal bone and cranial magnetic resonance weighted imaging scan（MRI）, muscle biopsy and mtDNA gene testing. Results:ENT subjective manifestations were present in 15 cases （53.6%） with sensorineural hearing loss（SNHL）, 4（14.3%） with tinnitus, 4（14.3%） with facial weakness, 3（10.7%） with dysphagia, 1（3.6%） with auditory agnosia. Ophthalmological and neurological symptoms included ptosis in 16 cases （57.1%）, exercise intolerance in 16（57.1%）, optic atrophy in 15（53.6%）, muscular atrophy in 6（21.4%）, and stroke-like episodes in 5（17.9%）. The results of objective examinations were as follows: DPOAE were not elicited in 18（64.3%） cases, ABR abnormalities in 18（64.3%） cases, hearing threshold shift in 15（53.6%） cases, AI normal and CM was not detected in all cases, SDS decreased in 6（21.4%） cases, facial ENoG abnormalities in 4（14.3%） cases, laryngeal ENoG abnormalities in 3（10.7%） cases, EMG abnormalities in 6（21.4%） cases, and ECG abnormalities in 8（28.6%） cases. Temporal CT were normal, but cranial MRI abnormalities were found in 19 cases（67.9%）, including central nerve demyelination, white matter hyperintensities, generalized cerebellar and cerebral atrophy, multiple cortical/subcortical infarct-like lesions, basal ganglia calcification. Conclusion:Multisystemic syndromes in MEM can present as a variety of otolaryngological, ophthalmological and neurological abnormalities, such as ptosis, audio-visual disturbance, exercise intolerance and stroke-like episodes etc. SNHL, tinnitus, auditory agnosia, facial weakness and dysphagia were ENT specific manifestations. SNHL in MEM is bilateral symmetrical progressive or of sudden onset since teenage. mtDNA testing may be helpful for adolescent patient whose SNHL was associated with neuromuscular symptoms. Muscle biopsy should be considered when middle-aged patients developed facial weakness and dysphagia. DPOAE and ABR are the optimal objective audiometric tests to monitor the progression of MEM associated with SNHL.

Neonatal exposure to monosodium glutamate results in impaired auditory brainstem structure and function

Excitotoxic injury during the neonatal period has been shown to result in neurodegenerative changes in several different brain regions. Exposure to monosodium glutamate (MSG) during the first two postnatal weeks results in glutamate neurotoxicity in the cochlea and has been shown to result in damage to cochlear hair cells and fewer neurons in the spiral ganglion. Further, we have shown that such exposure results in fewer neurons in the cochlear nucleus and superior olivary complex and abnormal expression of the calcium binding proteins calbindin and calretinin. Based on these findings, we hypothesized that neonatal MSG exposure would result in loss of neurons at more rostral levels in the auditory brainstem, and this exposure would result in abnormal brainstem auditory evoked potentials. We identified a significantly lower density of neurons in the spiral ganglion, heterogenous loss of neurons in the globular bushy cell-trapezoid body circuit, and fewer neurons in the nuclei of the lateral lemniscus and central nucleus of the inferior colliculus. The most severe loss of neurons was found in the inferior colliculus. Click-evoked auditory brainstem responses revealed significantly higher thresholds and longer latency responses, but these did not deteriorate with age. These results, together with our previous findings, indicate that neonatal exposure to MSG results in fewer neurons throughout the entire auditory brainstem and results in abnormal auditory brainstem responses.

Auditory phenotype of Smith-Lemli-Opitz syndrome.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive multiple congenital malformation and intellectual disability syndrome resulting from variants in DHCR7. Auditory characteristics of persons with SLOS have been described in limited case reports but have not been systematically evaluated. The objective of this study is to describe the auditory phenotype in SLOS. Age- and ability-appropriate hearing evaluations were conducted on 32 patients with SLOS. A subset of 21 had auditory brainstem response testing, from which an auditory neural phenotype is described. Peripheral or retrocochlear auditory dysfunction was observed in at least one ear of 65.6% (21) of the patients in our SLOS cohort. The audiometric phenotype was heterogeneous and included conductive, mixed, and sensorineural hearing loss. The most common presentation was a slight to mild conductive hearing loss, although profound sensorineural hearing loss was also observed. Abnormal auditory brainstem responses indicative of retrocochlear dysfunction were identified in 21.9% of the patients. Many were difficult to test behaviorally and required objective assessment methods to estimate hearing sensitivity. Individuals with SLOS are likely to have hearing loss that may impact communication, including speech and language development. Routine audiologic surveillance should be conducted to ensure prompt management of hearing loss.

Auditory brainstem response in preterm infants with bilirubin encephalopathy

AimTo clarify auditory brainstem response (ABR) in preterm infants with bilirubin encephalopathy and the relationships between ABR and clinical variables. MethodWe retrospectively reviewed the ABR waveforms of 56 preterm infants with BE and graded them as “no response”, “abnormal interwave separation”, or “normal”. Patient backgrounds, the peak total bilirubin level, the bilirubin/albumin ratio, verbal communication ability, and newborn hearing screening test results from an automated ABR evaluation had been collected during an earlier nationwide survey. ResultsThe frequency of abnormal ABR findings decreased with age. Verbal communication tended to be poorer in patients with more severe ABR abnormalities. ABR findings improved in 7 of 29 infants with available serial ABR data. Both gestational age and the peak total bilirubin level were relatively lower in patients with than in those without improved ABR findings. Newborn hearing screening using automated ABR evaluation yielded data consistent with manual ABR findings in 16 of 20 patients who underwent both examinations. ConclusionsABR abnormalities in preterm infants with bilirubin encephalopathy may improve over time, especially in those with a lower gestational age and peak total bilirubin level. Newborn hearing screening using automated ABR may fail to detect abnormalities in some infants.

Prolonged Auditory Brainstem Response in Universal Hearing Screening of Newborns with Autism Spectrum Disorder

Previous studies report prolonged auditory brainstem response (ABR) in children and adults with autism spectrum disorder (ASD). Despite its promise as a biomarker, it is unclear whether healthy newborns who later develop ASD also show ABR abnormalities. In the current study, we extracted ABR data on 139,154 newborns from their Universal Newborn Hearing Screening, including 321 newborns who were later diagnosed with ASD. We found that the ASD newborns had significant prolongations of their ABR phase and V‐negative latency compared with the non‐ASD newborns. Newborns in the ASD group also exhibited greater variance in their latencies compared to previous studies in older ASD samples, likely due in part to the low intensity of the ABR stimulus. These findings suggest that newborns display neurophysiological variation associated with ASD at birth. Future studies with higher‐intensity stimulus ABRs may allow more accurate predictions of ASD risk, which could augment the universal ABR test that currently screens millions of newborns worldwide.Lay SummaryChildren with autism spectrum disorder (ASD) have slow brain responses to sounds. We examined these brain responses from newborns' hearing tests and found that newborns who were later diagnosed with autism also had slower brain responses to sounds. Future studies might use these findings to better predict autism risk, with a hearing test that is already used on millions of newborns worldwide.

Neurodegenerative Diseases and the Auditory-Vestibular System

Neurodegenerative Diseases and the Auditory-Vestibular System

A nationwide survey of bilirubin encephalopathy in preterm infants in Japan

ObjectivesTo examine the clinical characteristics of bilirubin encephalopathy in preterm infants (pBE) in Japan. MethodsWe performed a two-step nationwide questionnaire survey. The initial survey determined the number of children with pBE. Using a structured questionnaire, the second survey clarified the clinical manifestations and characteristics of children with pBE, including the perinatal history, neonatal complications, neurological features, verbal communication, diet, and magnetic resonance imaging (MRI) and auditory brainstem response (ABR) findings. ResultsThe initial survey included 190 pBE infants, indicating an incidence of approximately 10 per year. Clinical information was available for 142 of them. The median gestational age was 26 weeks and the median birthweight was 883 g. As to neonatal complications, 20% had none, 25% had one complication, 54% had two or more. Head control was observed in 45% and functional gait in 8%. Purposeful hand use was seen in 41% of patients and verbal communication in 40%. MRI showed T2 hyperintensities in the globi pallidi in 111 of 136 patients, especially between 7 and 18 months of corrected age. ABR abnormalities were present in 88 of 117 patients. ConclusionspBE was infrequent but constantly observed during the study period, especially in very preterm infants, even in those with no severe neonatal complications. Severely impaired gross motor function and relatively preserved manual function and verbal communication were characteristic. MRI and ABR abnormalities will facilitate diagnosis.

Vestibular impact of Friedreich ataxia in early onset patients

BackgroundFriedreich ataxia (FRDA) is the most frequent form of inherited ataxias. Vestibular and auditory assessments are not commonly part of the check up for these patients despite hearing and balance complaints. Screening of vestibular and auditory function was performed in a large group of young patients with genetically confirmed FRDA.MethodsOur study included 43 patients (7–24 years of age). A complete vestibular assessment was performed including the canals function evaluation at 3 head velocities (bithermal caloric test, earth vertical axis rotation (EVAR) and head impulse test (HIT)) and otolith function evaluation (cervical vestibular evoked myogenic potentials). Information regarding the hearing evaluation of the patients were also retrieved including impedance tympanometry, distortion product otoacoustic emissions (DPOAEs), air and bone conduction audiometry and auditory brainstem response (ABR).ResultsVestibular responses were impaired for canal responses (only at high and middle head velocities) and vestibulospinal otolithic responses. Abnormal neural conduction in the central auditory pathways was frequently observed. Oculomotor abnormalities were frequent, mostly hypermetric saccades and gaze instability. Inhibition of the vestibulo-ocular reflex by fixation was normal.ConclusionsWe show that Friedreich ataxia, even at onset, frequently associate saccadic intrusions, abnormal ABRs and decreased vestibulo-ocular and vestibulospinal responses progressing over time. These sensory impairments combined with ataxia further impair patient’s autonomy. These vestibular, auditory and visual impairments could be used as markers of the severity and progression of the disease. Adding vestibular and auditory testing to Friedreich patient’s evaluation may help physicians improve patient’s management.