Auditory Brainstem Response Findings Research Articles

Diagnosis of Bilirubin Encephalopathy in Preterm Infants with Dyskinetic Cerebral Palsy

Introduction: Very preterm infants are susceptible to bilirubin neurotoxicity, the signs of which are unclear during early infancy. We investigated children born preterm and later diagnosed with bilirubin encephalopathy (BE) to gain insights into accurate early diagnosis. Methods: We identified 93 children born preterm and clinically diagnosed with BE who visited our hospital between 2006 and 2018. Perinatal history, findings of auditory brainstem response (ABR), brain magnetic resonance imaging (MRI), and functional outcomes were investigated retrospectively based on chart review. Results: The mean gestational age and birth weights were 27.2 weeks and 991 g, respectively. During the neonatal period, only 3% (2/71) had exchange transfusions, and none were diagnosed with acute BE. ABR was abnormal in 64% (51/80), but the majority (34/51) required no hearing aids. Brain MRI taken between 6 and 18 months of age revealed bilateral T2 hyperintensity of the globi pallidi in 91% (60/66); subsequently, the rate decreased with age. Functional communication outcomes were markedly superior to gross motor and hand function outcomes. Conclusion: For early diagnosis of BE, brain MRI is recommended at a corrected age of between 6 and 18 months, especially for those with abnormal ABR during early infancy, and even with no apparent history of marked neonatal hyperbilirubinemia.

Narrow-band chirp and tone burst auditory brainstem response as an early indicator of synaptopathy in industrial workers exposed to occupational noise

This study aims at characterizing and comparing the findings of auditory brainstem response (ABR) using narrow-band chirp (NB-chirp) and tone burst (TB) for both latency and amplitude parameters among those exposed to occupational noise and to determine which among the two serves as a better indicator of noise-induced cochlear neuropathy. Forty adult males in the age range of 20-35 years were considered, wherein 20 of them were exposed to noise > 80 dB (A) for 8 hours per day constituting Noise-exposed group; and Control group consisted of 20 individuals without occupational noise exposure. ABR was recorded using NB-chirp and TB for four frequencies at 80 dB nHL through Etymotic Research - 3A (ER-3A) Insert phones using Interacoustics Eclipse EP-25 in individuals with and without noise exposure. MANOVA was performed to compare between TB ABR and NB-chirp ABR between the two groups. Statistical analysis revealed a notable difference for NB-chirp comparisons between the two groups at three frequencies: 500 Hz, F(1, 38) = 10.6; 1000 Hz, F(1, 38) = 7.91; and 2000 Hz, F(1, 38) = 6.64. Whereas, the difference was evident at only 500 Hz: F(1, 38) = 4.98 in case of TB ABR. However, there was no significant difference seen at any of the frequencies for amplitude parameters in both TB and NB-chirp ABR. Latency of wave V using NB-chirp was considered to be a better indicator compared to TB, acting as a better clinical tool in early identification, diagnosis, and monitoring of noise induced hearing loss (NIHL).

Evaluation of dichotic listening performance in normal-hearing, noise-exposed young females

Recent animal studies have shown that intense noise exposures that produce robust temporary threshold shift (TTS) can inflict irreversible damage to the synaptic connections between the inner hair cells and auditory neurons. It was hypothesized that noise-induced cochlear synaptopathy may cause impaired acoustic encoding in the central auditory nervous system leading to impaired speech perception, particularly in challenging listening situations. The aim of the study was to evaluate the influence of high noise exposure background (NEB) on dichotic listening performance, speech-in-noise performance, and auditory brainstem responses (ABR) measured in young females with normal audiograms. The central hypothesis was that individuals with high NEB would exhibit reduced ABR wave I amplitude and subsequently would exhibit poorer performance on speech-in-noise and dichotic listening. In a sample of 32 females (14 with high NEB and 18 with low NEB) aged 18–35 years, the study compared behavioral hearing thresholds (from 250 to 16000 Hz), distortion-product otoacoustic emissions (DPOAEs, 1000–16000 Hz), click-evoked ABR, QuickSIN signal-to-noise ratio (SNR) loss and dichotic digit test (DDT). The results showed no clear association between NEB, and hearing thresholds, DPOAEs, click-evoked ABR measures, and QuickSIN SNR loss. Individuals with high NEB revealed significantly lower DDT scores and evidence of reduced right ear advantage compared to individuals with low NEB. The poorer performance in DDT and the ear asymmetry in DDT scores with normal ABR findings suggest that high NEB might alter the hemispheric organization of speech-sound processing and cognitive control. The clinical significance of the present findings is discussed.

Hidden hearing deficits in military service members with persistent post concussive symptoms

Individuals with persistent symptoms after mild traumatic brain injury (mTBI) often have auditory complaints. In this study, we used the auditory brainstem response (ABR) to determine whether cochlear synaptopathy could explain auditory symptoms. 69 adult military service members with mTBI and 25 adults without brain injury (NCT01611194 and NCT01925963) completed pure-tone audiometry, ABR, and central auditory processing tests. All participants were male, ages 21-50. 37/69 mTBI participants had measurable hearing loss, while another 20%-30% had hearing complaints or tinnitus. While mTBI participants with measurable hearing loss had reduced wave I and III amplitude and decreased III-V interpeak latency, those with no measurable hearing loss did not significantly differ from controls on any ABR parameter. Those with measurable hearing loss were also more likely to have abnormal central auditory processing. mTBI participants with no measurable hearing loss but who reported hearing concerns had some ABR findings (III-V interpeak latency, I and V amplitudes, V/I amplitude ratio) more like the measurable hearing loss mTBI group than normative controls. Cochlear synaptopathy may have contributed to some of the auditory impairment in service members with mTBI with measurable hearing loss. However, these results are likely confounded by cochlear hair cell damage.

Auditory brainstem response (ABR) findings in males and females with comparable head sizes at supra-threshold and threshold levels

Background and purposeGender disparities in auditory brainstem response (ABR) results have been reported but the exact reasons remain controversial. Difference in head size between genders has been suggested but the literature is lacking, particularly at threshold levels. In this short communication, we compared ABR results between males and females with comparable head sizes at supra-threshold and threshold levels. Materials and methodsIn this comparative study, of 58 healthy young adults, 30 of them (17 females and 13 males) with comparable head sizes underwent the standard ABR testing. Wave V latencies and ABR thresholds were determined and analyzed accordingly. ResultsAt the supra-threshold level, significantly shorter wave V latencies were found in females than in males (p = 0.029). This difference was substantive (d = 0.86) and persisted even when the head size was included in the analysis (p = 0.032). In contrast, no significant differences in ABR thresholds were found between genders (p > 0.05). ConclusionsSignificant gender differences in ABR results among young adults were only found at the supra-threshold level, which were not related to the head size. Based on the study outcomes, gender-specific normative data for ABR are still beneficial for clinical applications, particularly when recording ABR at high stimulation levels.

Complex auditory brainstem response findings in cognitively impaired elderly

Complex auditory brainstem response findings in cognitively impaired elderly

Prognosticating hearing outcome in patients with idiopathic sudden sensorineural hearing loss by means of otoacoustic emissions and auditory brainstem response.

This is an analytic-descriptive study, parallel with a randomized, controlled trial performed at Amir'Alam Hospital, a tertiary referral center, with the aim of evaluating the correlation between otoacoustic emission (OAE) and auditory brainstem response (ABR) findings with hearing outcome after treatment of idiopathic sudden sensorineural hearing loss (SSNHL). Sixty patients with idiopathic SSNHL who presented to the emergency services and otology clinics between 2012 and 2014, and whose symptoms had begun <10 days previously, enrolled in this study. Before commencing treatment, distortion-product OAE (DP-OAE) and ABR were performed for all patients. They also underwent magnetic resonance imaging ± gadolinium. Therapeutic intervention was done in a parallel randomized, controlled trial, and responders to the medical therapy were selected for our final analysis. There was no significant correlation between the OAE record and responsiveness to treatment, but there was a correlation between ABR presence and the probability of responsiveness in patients with profound hearing loss who responded to medical therapy and had at least wave V ABR. However, in those who had no recorded wave, the response to treatment was variable. In conclusion, in patients with profound hearing loss, studying the waves of ABR could be a factor in predicting hearing loss resolution after treatment.

Noise History and Auditory Function in Young Adults With and Without Type 1 Diabetes Mellitus

The purpose of this study was to examine the relationship between noise exposure history, type 1 diabetes mellitus (DM), and suprathreshold measures of auditory function. A cross-sectional study was conducted; 20 normal-hearing participants without type 1 DM were matched on age and sex to 20 normal-hearing participants with type 1 DM (n=40). Participants, all having normal audiometric thresholds, completed noise history questionnaires and a battery of auditory physiological tests including transient evoked otoacoustic emissions, distortion product otoacoustic emissions, and auditory brainstem responses (ABR) at 80 dB nHL and at 2 different stimulus rates in both ears. Amplitude and latency for waves I and V are presented. Statistical analysis included analysis of variance and multivariate linear regression. No statistically significant difference for noise exposure history, otoacoustic emissions (OAE), or ABR findings were found between type 1 DM and matched controls. Males and females showed statistically significant differences for OAE amplitudes and ABR amplitude and latencies. However, no statistically significant relationship was found between noise outcomes and OAE or ABR findings. No statistically significant relationship between noise history and our suprathreshold ABR or OAE findings was indicated for individuals with type 1 DM or matched controls. The lack of evidence of noise related neuropathology might be due to inadequate noise exposure or lack of comorbidities in our DM group. Implications of these findings are discussed.

Audiological findings in children with ataxia-telangiectasia (A-T) syndrome

AimTo assess peripheral and central hearing in children with A-T. Method3 children diagnosed with A-T according to the diagnostic criteria for A-T of the European Society for Immunodeficiencies. Involuntary movements were seen in the form of chorea-athetosis together with tremors. They were examined to assess both peripheral and central hearing was assessed (hearing thresholds). Sound-field testing, tympanometry, acoustic reflexes, Otoacoustic Emissions (OAEs) and Auditory Brainstem Responses (ABR) were done for all of them. ResultsBasic Audiological evaluation is of a limited value as the children are not co-operative. Sound field testing could not be done. Bilateral normal middle ear functions as reflected by Tympanometry and Acoustic Reflexes. Advanced Audiological evaluation including OAEs and ABR are more valuable in assessing hearing in children with A-T. Bilateral pass response at all test frequencies in DPOAEs. Abnormal ABR findings were obtained in the form of a delay in wave V latency more than 2 SD with subsequent increased in I-V interpeak latency with no significant interaural latency difference. ConclusionConsistent with bilateral normal peripheral hearing sensitivity with central hearing affection. LimitationsThe rarity of the disease, make it difficult to be applied on many cases.

The relationship between auditory brainstem response, nerve conduction studies, and metabolic risk factors in type II diabetes mellitus

Few studies have reported a correlation between auditory brainstem response (ABR) findings and nerve conduction studies (NCSs). The correlation between ABR findings and the metabolic profile of these patients is not well documented in previous studies. The present study was designed to investigate the impact of the disturbed metabolic profile (hyperglyceridemia and hyperlipidemia) in diabetic patients on the peripheral nervous system as well as the auditory brainstem response. The present study aimed to detect the effect of diabetic control on the presence of abnormal ABR and/or peripheral nerve affection in Egyptian diabetic patients. The study was conducted on two groups: the diabetic group (n=68) and the control group, which was matched for age, sex, blood pressure, and BMI (n=60). All participants were subjected to clinical assessment, basic audiologic assessment, brainstem auditory evoked potential, NCS, and metabolic profile [serum level of glycated hemoglobin (HbA1c%) and lipid profile]. There was a significant increase in absolute wave latencies of ABR and interpeak latencies (IPLs) in the diabetic group compared with the control group. Twenty-six (38.2%) patients had abnormal ABR values. IPLs (I–III and III–V) were significantly negatively correlated with sensory conduction velocity of the sural, median, and ulnar nerves as well as F-wave latency of the posterior tibial, median, and ulnar nerves (P=0.01 and 0.001, respectively). Moreover, IPL III–V and sural sensory conduction velocity were significantly correlated with HbA1c% and total cholesterol, as well as triglyceride serum levels. Brainstem dysfunction and ABR changes are common in patients with type II diabetes mellitus. These changes are significantly correlatedto NCS parameters on one hand and serum HbA1c% and lipid profile (total cholesterol and triglycerides) on the other hand.

Role of cervical vestibular evoked myogenic potentials (cVEMP) and auditory brainstem response (ABR) in the evaluation of vestibular schwannoma

IntroductionCervical vestibular evoked myogenic potentials (cVEMP) can assess the integrity of the inferior vestibular nerve thereby promising to be a useful tool in the audiological test battery to diagnose vestibular schwannoma. ObjectiveTo ascertain the utility of cVEMP in diagnosis of vestibular schwannoma in conjunction with the ABR and to evaluate whether the size of lesion has any effect on the cVEMP measures. MethodsCase-files of 15 known cases of vestibular schwannoma whose pure tone audiometry, auditory brainstem response (ABR), cVEMP and radiological investigation findings were available, were included in the study. Patients were categorised as large or small tumours based on the size. The absolute and inter-peak latencies of ABR, amplitudes of waves V and I, and inter-aural latency difference of wave V of ABR; and latency of P1 and N1 of cVEMP and amplitude of P1–N1 complex were considered in the study. ResultsThere were eight large and nine small tumours. All the patients with large tumours showed significant severity of hearing loss whereas only three out of nine patients with small tumours showed severe to profound deafness in the affected ear. The rest showed hearing status ranging from normal hearing sensitivity to moderate hearing loss. Most of the patients with large tumours showed complete absence of ABR in the affected ears with no identifiable wave-peaks. ABR in small tumours exhibited delayed III–I and delayed V–I interpeak latency interval (IPL). Four out of five patients with large unilateral tumours revealed contralateral effects of reduced amplitude or absence of cVEMP. On the contrary, six out of eight unilateral small tumours showed a normal cVEMP response in the contralateral ear. Both the patients with NF2 in the present study demonstrated cVEMP abnormalities. ConclusionABR and cVEMP, when used in combination, can be of immense use in identification of neuro-otologic conditions such as vestibular schwannoma and bilateral tumours in NF2. In the evaluation of unilateral vestibular schwannoma, abnormal contralateral findings of cVEMP and ABR are strongly indicative of the tumour size >2.5cm. In unilateral severe to profound loss wherein ABR in poorer ear cannot give information of site-of-lesion, cVEMP can help in the differentiation.

Audiological findings in a group of neurologically compromised children: A retrospective study

Background . Hearing loss is more prevalent in developing countries. Later diagnosis of hearing loss will result in delayed access to rehabilitation. It is typically more difficult to obtain subjective information required in a hearing test from neurocompromised children, causing audiologists to frequently turn to objective measures such as the auditory brainstem response (ABR) measure to obtain this information. Objective . To describe the ABR results in a group of neurologically compromised children and to establish a relationship between ABR findings and behavioural audiometry results, where these existed. Methods . A retrospective review was conducted on 40 ABR patient records of neurologically compromised participants aged 5 months to 10 years. Behavioural audiometry results were sought where these existed. Hearing status was described per ear for objective and behavioural results, and descriptive statistics were conducted. Results . Behavioural audiometry results were obtained in 72.5% of ears. Results correlated between ABR and behavioural audiometry for only 7.5% of ears, which were all diagnosed with normal hearing. About 12.5% of ears were misdiagnosed with behavioural audiometry. Premature infants were most likely to cope with behavioural audiometry. Hearing loss was highest in participants with cerebral palsy, Down syndrome, prematurity and retroviral disease. Conclusions . Behavioural audiometry appears to be a largely unreliable method of testing the hearing of children diagnosed with neurological disorders, as results were obtained in only 27.5% of the study sample; however, it remains the gold standard in paediatric hearing testing to evaluate the entire auditory system and provides information on how a child processes sound. Hearing thresholds should be established via objective testing. Conditioning should continue for a behavioural audiological test battery, with adaptations for the child’s developmental ability.

Auditory brainstem response and late latency response in individuals with tinnitus having normal hearing.

Tinnitus is a commonly encountered complaint in routine audiology practice. The pathophysiology and exact generation site of tinnitus is not precisely established. Auditory brainstem response (ABR) and late latency response (LLR) findings in individuals with tinnitus show mixed results in the literature. Majority of studies have focused on individuals having tinnitus with peripheral hearing loss. The present study explores ABR and LLR characteristics among tinnitus patients with normal audiometric presentation; with no direct indication of any cochlear lesion. This study aims at characterizing the ABR and LLR findings in individuals with tinnitus having normal audiometric presentation. ABR and LLR waveform characteristics were recorded and compared between participants with tinnitus (Group 1) and those without tinnitus (Group 2). The ABR analysis indicated no significant differences in latency and amplitude between Groups 1 and 2. However, patients with tinnitus showed abnormally reduced absolute amplitudes of peaks I and V. LLR analysis indicated no significant differences in latency and amplitude between Groups 1 and 2 except enhanced amplitude of P1. The reduced amplitude of peaks I and V along with normal absolute latencies of peaks I, III and V indicate that the origin of tinnitus is possibly due to reduced excitation of auditory nerve fibres arising from a peripheral hearing loss beyond 8 kHz. The P1 amplitude enhancement could be attributed to mechanism explaining central gain model; which suggests that central auditory structures recalibrates the mean firing rate, considering the reduced output from sensory structures, generating neural noise perceived as tinnitus.

Noise-induced tinnitus: auditory evoked potential in symptomatic and asymptomatic patients

OBJECTIVES:We evaluated the central auditory pathways in workers with noise-induced tinnitus with normal hearing thresholds, compared the auditory brainstem response results in groups with and without tinnitus and correlated the tinnitus location to the auditory brainstem response findings in individuals with a history of occupational noise exposure.METHOD:Sixty individuals participated in the study and the following procedures were performed: anamnesis, immittance measures, pure-tone air conduction thresholds at all frequencies between 0.25–8 kHz and auditory brainstem response.RESULTS:The mean auditory brainstem response latencies were lower in the Control group than in the Tinnitus group, but no significant differences between the groups were observed. Qualitative analysis showed more alterations in the lower brainstem in the Tinnitus group. The strongest relationship between tinnitus location and auditory brainstem response alterations was detected in individuals with bilateral tinnitus and bilateral auditory brainstem response alterations compared with patients with unilateral alterations.CONCLUSION:Our findings suggest the occurrence of a possible dysfunction in the central auditory nervous system (brainstem) in individuals with noise-induced tinnitus and a normal hearing threshold.

Auditory brainstem response in term and preterm infants with neonatal complications: the importance of the sequential evaluation.

Introduction Literature data are not conclusive as to the influence of neonatal complications in the maturational process of the auditory system observed by auditory brainstem response (ABR) in infants at term and preterm. Objectives Check the real influence of the neonatal complications in infants by the sequential auditory evaluation. Methods Historical cohort study in a tertiary referral center. A total of 114 neonates met inclusion criteria: treatment at the Universal Neonatal Hearing Screening Program of the local hospital; at least one risk indicator for hearing loss; presence in both evaluations (the first one after hospital discharge from the neonatal unit and the second one at 6 months old); all latencies in ABR and transient otoacoustic emissions present in both ears. Results The complications that most influenced the ABR findings were Apgar scores less than 6 at 5 minutes, gestational age, intensive care unit stay, peri-intraventricular hemorrhage, and mechanical ventilation. Conclusion Sequential auditory evaluation is necessary in premature and term newborns with risk indicators for hearing loss to correctly identify injuries in the auditory pathway.

Speech evoked auditory brainstem response findings in children with epilepsy

ObjectivesChildren with epilepsy are at a considerable risk of cognitive impairment and school failure. Previous studies have typically documented abnormal responses in children with epilepsy at cortical level using speech stimuli. Recent studies reported that abnormal neural encoding of a speech syllable could be detected at the level of the brainstem using speech-evoked auditory brainstem response (ABR). The aim of this study is to investigate speech-evoked (ABR) results in children with epilepsy. MethodsThe study group consisted of 38 recently diagnosed epileptic children; none of them has received antiepileptic therapy. They were 22 males and 16 females with age 9.1±3.1 years. The control group consisted of 38 healthy normal hearing children with matched age and gender distribution. All subjects underwent full history taking, basic audiologic evaluation including pure-tone, speech audiometry and immittance testing. Click ABR response was recorded monaurally from both ears at 90dB nHL then speech ABR was recorded monaurally from each ear at 80dB SPL. ResultsThough the study group disclosed normal click ABR compared to age matched normative values, speech-evoked ABR revealed a delayed waves V and A latencies in both ears. These findings reflect abnormal neural encoding of speech at the level of brainstem. The younger the age of epileptic child the more prolonged wave A latency and increased V/A inter-latency values. ConclusionsSpeech-evoked ABR results denote abnormal timing in the brainstem; such brainstem abnormality could be detected by speech evoked ABR rather than conventional click evoked ABR.

Brain magnetic resonance imaging findings and auditory brainstem response in a child with spastic paraplegia 2 due to a PLP1 splice site mutation

A boy with spastic paraplegia type 2 (SPG2) due to a novel splice site mutation of PLP1 presented with progressive spasticity of lower limbs, which was first observed during late infancy, when he gained the ability to walk with support. His speech was slow and he had dysarthria. The patient showed mildly delayed intellectual development. Subtotal dysmyelination in the central nervous system was revealed, which was especially prominent in structures known to be myelinated during earlier period, whereas structures that are myelinated later were better myelinated. These findings on the brain magnetic resonance imaging were unusual for subjects with PLP1 mutations. Peaks I and II of the auditory brainstem response (ABR) were normally provoked, but peaks III-V were not clearly demarcated, similarly to the findings in Pelizaeus-Merzbacher disease. These findings of brain MRI and ABR may be characteristic for a subtype of SPG2 patients.

Audiological assessment modalities in children with multiple handicaps and parents′ perception

Aim of the Study: Children with multiple disabilities have combination of various disabilities. Accurate hearing evaluation is difficult in this population. Audiologists generally employ a test battery approach, which includes combining findings of parent impression with behavioral observation audiometry (BOA) as well as auditory brainstem response (ABR) findings. Present study was done to find if there exists correlation among various steps in test battery for the children with multiple handicaps as well as to find out which disability is most common among this population. Materials and Methods: Total 103 numbers of children with multiple handicaps were chosen at random who were referred to CU Shah Institute of Audiology and Speech Therapy for audiological assessment. The three steps involved in assessment that is parental impression, BOA, and ABR findings were taken into account. The relationship was obtained using data analysis. Results: It was found that among children with multiple handicaps referred for audiological assessment, mental retardation (MR) was the most common (32.03%). Also, it was found that there were more contradictory findings between parent impression and ABR (48%) when compared with parent impression with BOA (38%). In between BOA and ABR, contradictory findings were found in 41% of cases. Conclusion: There are wide contradictions among various steps involved in assessment of children with multiple handicaps. Implication: Audiologist should use a test battery approach to assess hearing ability of this population and audiologists should interpret findings carefully at each level.

Friend or foe? Effect of oral resveratrol on cisplatin ototoxicity

Our objectives were to study effects of orally administered resveratrol (RV) against cisplatin (CDDP) ototoxicity in different doses and to investigate ultrastructural changes in the cochlea and brainstem. In vivo study using an animal model. Thirty-two male Wistar albino rats were divided into six groups. Baseline distortion product otoacoustic emissions (DPOAEs) and auditory brainstem response (ABR) measurements were made. In groups I, II, and III, only saline, RV, and CDDP were given, respectively. Group IV, V, and VI animals were administered 10 mg/kg/day, 1 mg/kg/day, and 0.1 mg/kg/day of RV for 10 days, respectively, before 16 mg/kg CDDP injections were administered on day 11. All animals were sacrificed after repeated DPOAEs and ABR measurements were made on day 14. Cochleas of animals were investigated with transmission electron microscopy. Apoptosis were investigated with caspase-3 activity and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method in the brainstem. In groups IV and V, DPOAEs and ABR findings revealed that oral administration of RV 10 mg/kg/day and 1 mg/kg/day doses before CDDP injection enhanced ototoxicity. In group VI, electomicroscopy revealed better ultrastructural findings than in the cisplatin group; however, these changes were not reflected in the audiological findings accordingly. Our results implied that there were noticeable differences between different oral RV doses used for cisplatin ototoxicity. Especially in higher doses, RV was observed to enhance cisplatin ototoxicity.

Audiovestibular Characteristics of Small Cochleovestibular Schwannomas in Neurofibromatosis Type 2

Objectives: Describe the relationship between cochleovestibular schwannoma (CVS) volume, audiovestibular changes, and magnetic resonance imaging (MRI) findings in patients with neurofibromatosis Type 2 (NF-2). Methods: Subgroup analysis of NF-2 prospective natural history study from June 2008 to June 2011. Subjects: NF-2 patients with small treatment- naïve CVS (volume &lt; 1cm3) by ear. N = 49 ears, 32 patients. Setting: Quaternary medical research institute. Intervention: None. Outcome Measurements: Tumor size, auditory brainstem response (ABR), audiogram (4-frequency PTA - 0.5, 1, 2, 4KHz), vestibular evoked myogenic potential (VEMP), caloric videonystagmography (VNG), rotary chair testing (240°/sec velocity step test), and magnetic resonance imaging (MRI) findings. Results: Larger tumor volume (mean 0.489cm3; 95% confidence interval [CI] 0.313-0.664) correlated with abnormal ABR findings, compared to smaller tumors with normal ABR (mean 0.151cm3; 95%CI 0.89-0.213). Larger tumors also correlated with weak caloric response (mean 0.520cm3; 95%CI 0.300-0.741 vs. mean 0.199cm3; 95%CI 0.102-0.296). Tumor volume was not significantly correlated with PTA, VEMP, or rotary chair testing. Elevated intralabyrinthine protein on MRI fluid-attenuated inversion recovery sequences was correlated with larger tumor size (mean volume 0.331cm3; 95%CI 0.246-0.419 vs. 0.055cm3; 95%CI 0.008-0.103) and abnormal ABR and PTA ( P &lt; 0.05), but it did not correlate with VEMP or caloric responses. Conclusions: In our sample, ABR, caloric response, and intralabyrinthine protein correlated with tumor volume, but PTA, VEMP, and high velocity step testing did not. Abnormal ABR and PTA were correlated with elevated protein. These findings may provide insight on the effect of small CVS on the inner ear and cochleovestibular nerves, which may aid in their management.