Absolute Latencies Research Articles

Auditory brainstem functioning in individuals with misophonia

PurposeMisophonia is not investigated much from an audiological perspective. Our study aims to examine the processing of the auditory retro-cochlear pathways in individuals with misophonia. MethodsA cross-sectional study was conducted among university students who had misophonia. The revised Amsterdam Misophonia Scale was used to determine the severity of misophonia. Participants were divided into mild and moderate-severe misophonia and compared with the healthy control group. Auditory Brainstem Response testing was recorded from all the individuals with misophonia. The absolute latency, amplitude, inter-peak latency difference, and inter-rate latency difference were compared between the groups. ResultsOne-way ANOVA result showed no significant difference in all the parameters of auditory brainstem response between the groups. These results are suggestive of normal brainstem processing in individuals with misophonia. ConclusionsThe study concludes that the auditory pathway up to brainstem areas is intact in individuals with misophonia. Further studies are essential on a larger population for generalizing the results.

Chiari-like malformation in Cavalier King Charles Spaniels impacts brainstem auditory-evoked response latency results.

To evaluate hearing loss in Cavalier King Charles Spaniels (CKCS), breed-specific brainstem auditory-evoked response (BAER) testing parameters are needed to help assess the Chiari-like malformation (CM) grade. The purpose of this study was to establish breed-specific BAER data and to determine if BAER indexes differed based on the CM grade. We hypothesized that there would be latency differences based on the CM grade. 20 CKCS without apparent hearing abnormalities as assessed by the owners. Under general anesthesia, CKCS underwent a CT scan (to assess the middle ear), BAER testing, and MRI (to assess the grade of CM). No CKCS had CM0. Nine (45%) CKCS had CM1; 11 (55%) had CM2. All had at least 1 morphologic abnormality in waveforms. Absolute and interpeak latencies were reported for all CKCS and compared between CM grades. The median threshold for CKCS with CM1 was 39 and for CM2 was 46. Absolute latencies for CKCS with CM2 were consistently longer than those for CKCS with CM1 with the exception of waves II and V at 33 dB. Significant differences were found for wave V at 102 dB ( P = .04) and wave II at 74 dB (P = .008). Interpeak latency comparisons were inconsistent between CM1 and CM2. Breed-specific BAER data for CKCS with CM1 and CM2 were established. The results suggest that CM impacts BAER latency results, but the influence of the malformation is not always statistically significant or predictable.

Association of Cord Ferritin Levels with Brain Stem Evoked Response Audiometry in Newborns.

Iron is an important nutrient and it plays a pivotal role in myelin formation and neurotransmitter synthesis, thus contributing to normal neurological activity. Ferritin is a reliable indicator of the tissue iron stores and in-utero stores can be well measured by cord ferritin levels. The objective of this study was to evaluate the effects of umbilical cord ferritin levels (CFL) on the brain stem evoked response audiometry (BERA) This prospective observational study was conducted in a tertiary care centre of North India with a sample size of 100 inborn neonates. After evaluation of the umbilical cord ferritin levels the study cohort was divided into Group A( UCF<75ng/ml) and Group B(UCF>75ng/dl). All subjects were subjected to BERA. A detailed analysis of CFL and BERA was done and statistically analysed. Neonates in group B had significantly prolonged absolute peak latency of wave I, III and V and interpeak latency of wave III-V when compared to group A. The Pearson correlation also showed negative correlation of CFL with absolute peak latency of wave I, III, and V and interpeak latency of wave III-V. Among the maternal and neonatal variables, highly significant correlation was noted between absolute latency of wave I, III and V, CFL and cord hematocrit. The Pearson correlation showed negative correlation of absolute peak latency of wave I, III and V with maternal haemoglobin (Hb), neonatal birth weight, CFL,s and cord hematocrit values. A negative Pearson correlation was noted between interpeak latency of wave III-V with neonatal birth weight and cord hematocrit level, interpeak latency of wave I-V with neonatal birth weight and between interpeak latency of wave I-III with cord hematocrit values. CFL's significantly affect the absolute peak latency of wave I, III and V and it also affects the interpeak latency of wave III-V. This may be attributed to slow conduction time secondary to altered myelination. CFL's should be considered as a routine protocol in neonates to detect early compromises in the process of myelination and brain maturation.

A cross-sectional study of severe acute malnutrition impact on auditory evoked potentials in children age 6–59 months

Background: Malnutrition is a public health concern in India. According to NFHS-5, the number of children under 5 years who are stunted (less height-for-age) and underweight (less weight-for-age) in India, are 35.5% and 32.1%, respectively. Many researchers reported that malnutrition affects myelination and neural maturation of the auditory brainstem pathway. Aims and Objectives: In this study, auditory evoked potential (AEP) parameters were studied in severly acute malnutrition (SAM) children of 6 months to &lt;5 years of age. Materials and Methods: Fifty children, with severely malnourished (Their weighted age was 51–60% of the expected weight, and height for age &lt;85% of the expected height) and 50 healthy children (with weight &gt;80% of expected with normal height for their age), aged 6–59 months were included in the study. The parameters of AEPs were recorded using RMS-EMG EP MARK II, a 4-channel machine. Results: In our study, 30 (60%) males and 20 (40%) females had severe acute malnutrition. There were significant differences in the mean latencies of the waves I to V and the mean interpeak latencies (IPLs) of the waves I-III and I-V on the right and left ears between the study and control groups (P&lt;0.05). The mean IPLs of I-III and I-V on the right side were found to be longer in the SAM group than in the control group (P&lt;0.05. While the mean absolute peak latencies of wave, I found prolonged on both ears in the children with SAM (P&lt;0.05). Conclusion: In the present study, severely acute malnourished children showed changes in AEPs characterized by absolute wave prolonged latencies and interpeak intervals compared with normally nourished children.

Physiological and electrophysiological evaluation of the hearing system in low birth weight neonates treated with cholestin: a cohort study

BackgroundInfections in neonates are mainly caused by sepsis and are the most important complications of low birth weight. In the treatment of these infections, it is common to use broad-spectrum antibiotics such as cholestin. Cholestin can cause changes in the latency of brainstem-evoked response waves. The current cohort study tried to investigate the probability of changes caused by cholestin in LBW neonates and benefiting from two common tests to identify the hearing system in neonates after treatment by cholestin and compared them with a control group.MethodsThe study was an exposure-based cohort, during which hearing damage caused by receiving cholestin was evaluated in 104 low birth weight neonates, in two groups (52 exposure and 52 no-exposure to cholestin). OAE and ABR tests were performed at the age of 3 months to identify complications in two groups and their results were compared.ResultsThe absolute latency of waves I, III, and V in the brainstem evoked response test with an intensity of 80 dB Hl showed a significant difference in the exposure group with the control group. The interpeak latency of the waves as well as the effect of the drug on the gender of the infants did not show significant differences with the control group.ConclusionCholestin did not affect the axonal or synaptic transmission time of the auditory nerve to the brainstem. It is possible that the simultaneous presence of risk factors, such as the use of cholestin, low birth weight, noises in the intensive care unit, and other unknown factors, can be effective in the change of the absolute latency of waves.

Auditory Pathway Maturation in Full-term Small for Gestational Age Children: A Systematic Review with Meta-analysis.

Introduction Factors of intrauterine growth restriction have been responsible for the births of full-term babies small for their gestational age (SGA). Scientific evidence points that this restriction can cause changes in the neural maturation process. Objectives To analyze the absolute latencies and interpeak intervals of brainstem auditory evoked potential waves in full-term and SGA children to investigate whether there are changes of neural maturation in this population. Data Synthesis The search for articles that reported the assessment of brainstem auditory evoked potential in SGA newborns compared with a control, appropriate for their gestational age, both born full-term, for the entire period available in the database research until October 31, 2021 was performed based on the MEDLINE/PubMed Central and on the Latin America and the Caribbean Health Sciences Literature and Virtual Health Library electronic databases. A total of 311 studies were found in the database research. Out of this total, 10 studies were included in the review, 5 of which were eligible for the meta-analysis, involving a total of 473 participants of both genders, with 193 participants belonging to the study group and 280 to the control group. Differences between the groups were only observed in the absolute latency of wave V (95% confidence interval [CI]: 0.02-0.15; p < 0.01). Conclusion The SGA condition is responsible for the appearance of brainstem neural conduction dysfunction measured by the brainstem auditory evoked potentials, probably by the maturation process of the auditory pathway of this population.

Standardization of Latency and Amplitude Values of Short, Middle and Long Latency Auditory Evoked Potentials in Adults.

Introduction Auditory processing refers to the efficiency and effectiveness with which the central auditory nervous system uses auditory information. Middle- and long-latency auditory evoked potentials are objective electrophysiological tests that can complement the diagnosis of alterations involving central auditory processing. Objective To standardize latency and amplitude values for short-, middle-, and long-latency auditory evoked potentials in adults with normal hearing thresholds. Methods This is a cross-sectional study. Thirty-three adults with normal hearing thresholds, without hearing complaints, and with normal central auditory processing were evaluated. All underwent basic audiological evaluation, central auditory processing assessment, and short-, middle-, and long-latency auditory evoked potentials. Results Absolute latency and interpeak values for middle- and long-latency auditory evoked potentials were lower than internationally suggested. However, for the brainstem auditory evoked potential, the means were within the range considered as normal, as suggested in the equipment. Conclusion The present study provided measurements of normal latencies and amplitudes for short-, middle-, and long-latency auditory evoked potentials in adults.

Comparison of Chirp Versus Tone Burst- and Click-Evoked Masseteric Vestibular Evoked Myogenic Potentials in Normal-Hearing Adults.

This study aimed at comparing narrowband Claus Elberling level-specific chirp (NB CE-Chirp)-, click-, and tone burst-evoked masseteric vestibular evoked myogenic potentials (mVEMPs). Within-group study design and purposive sampling were performed. A total of 25 normal-hearing individuals participated in the study. The zygomatic electrode montage was used to elicit ipsilateral mVEMP responses using a 500-Hz NB CE-Chirp, a click of 100-μs duration, and a 500-Hz tone burst stimulus. Each of the responses was analyzed based on the absolute peak latency of P11 and N21, the electromyography-scaled peak-to-peak amplitude of the P11-N21 complex, and the interaural asymmetry ratio. A total of 50 ears were tested and had 100% mVEMP responses. The latencies of click-evoked and 500-Hz NB CE-Chirp-evoked mVEMPs were significantly shorter than those of 500-Hz tone burst-evoked mVEMPs (p < .05) for both ears. It revealed a significantly superior P11-N21 amplitude of the 500-Hz NB CE-Chirp and tone burst than clicks for both ears. Intraclass correlation coefficient revealed moderate to excellent test-retest reliability for mVEMP parameters across three different stimulations. The present study supports 500 Hz NB CE-Chirps as effective and reliable stimuli as tone bursts in eliciting mVEMP responses.

Effects of latent iron deficiency on auditory neural maturation during early infancy in infants above 35 weeks' gestation.

Latent iron deficiency (LID) at birth is associated with prolonged latencies in auditory brainstem response (ABR), a surrogate for neural maturation. This study aimed to compare wave and inter-peak latencies of ABR at birth and at 4-6 months of age in infants ≥35 weeks of gestation with normal iron status (NIS) and LID. Neonates born at ≥35 weeks were screened. Cord ferritin value≤75ng/mL and >75ng/mL were classified as LID and NIS, respectively. ABR was performed within 48h of birth. The absolute latencies of waves I, III, and V, and inter-peak latencies I-III, III-V, and I-V were computed. Infants were reassessed at 4-6 months of age for hemoglobin, serum ferritin levels, and ABR latencies. In total, 160 neonates were enrolled. The mean (SD) birth weight and gestational age of the study population were 2843 (384) g and 38.3 (1.1) weeks, respectively. Approximately 122 infants completed follow-up until 4-6 months of age: 37 in the LID group and 85 in the NIS group. Overall, the wave and interpeak latencies in both groups at birth were comparable. At 4-6 months, the absolute latencies of waves I, III, and V, and inter-peak latencies I-III, III-V, and I-V were decreased and were comparable in both groups. Among small-for-gestational-age neonates, inter-peak latencies in I-III and I-V at birth were significantly longer in the LID group than in the NIS group. Nine (24.3%) infants in the LID group and none in the NIS group were iron-deficient at 4-6 months of age. There was no difference in wave or inter-peak latencies at birth and at 4-6 months of age in neonates aged ≥35 weeks with or without LID. However, infants with LID at birth have a significant risk of iron deficiency at 4-6 months of age. CTRI/2017/08/009379 (www.ctri.nic.in).

Mismatch Negativity and Auditory Brain Stem Response in Children with Autism Spectrum Disorders and Language Disorders.

Language disorders (LD) in autism spectrum disorders (ASD) are highly variable and has a severe impact on the level of functioning in autistic children. Early diagnosis of these language disorders is essential for early interventions for children at risk. The electrophysiological measurements are considered valuable tools for determining language disabilities in children with ASD. This study aimed to study and compare ABR and MMN in autistic children with language disorders. This study included a group of typically developing children and a group of children diagnosed with autistic spectrum disorders and language disorders. Both groups were matching according to age and gender. After confirming bilateral normal peripheral hearing sensitivity, ABR was done and both absolute and interpeak wave latencies were correlated. MMN using frequency oddball paradigms were also obtained and correlated. More abnormalities were reported in ABR test results in the form of delayed absolute latencies and prolonged interpeak intervals. Also, we reported prolonged latencies of MMN. Consequently, both ABR and MMN are complementary test in evaluating autistic children with language disorders. Our results support the hypothesis of remarkable dysfunction in basic auditory sound processing that may impact the linguistic development of autistic children.

Effects of sex and gestational age on the auditory brainstem responses among two ears in moderate preterm infants

Objectives Auditory cortex in each hemisphere mostly receives the sounds from the opposite ear. The present study aimed at the contralateral dominance of auditory brainstem response (ABR) among the ears in preterm neonates by comparing sex and gestational age. Methods Transient Evoked Otoacoustic Emission (TEOAE) and Auditory Brainstem Response (ABR) were recorded at 3 months postconceptional age (PCA). The performance of two ears in ABR was compared. In addition, performance of each ear was analysed in females and males. A comparison of moderate gestational age also was performed. Twenty preterm neonates from 32 to 36 weeks gestational age admitted to the neonatal intensive care unit at Shafizadeh Children’s Hospital were participated. Results No significant asymmetry in ABR absolute latency and inter-peak intervals of right and left ears in preterm infants was noticed. Females and males did not demonstrate statistically significant values in ABR latencies. Moreover, the results of four gestational ages were not statistically different from each other. Conclusion The maturation of the auditory brainstem pathways most likely take places in both hemispheres simultaneously, independent of sex in preterm infants. Changes of gestational age in each month do not impact on the maturation of the auditory brain pathways.

The association of auditory function measures with low-level methylmercury from oceanic fish consumption and mercury vapor from amalgam: The Seychelles Child Development Study Nutrition 1 Cohort

BackgroundSome authors have reported that low-level exposure to methylmercury (MeHg) adversely impacts measures of auditory function. These reports, however, are not consistent in their findings. Consequently, we examined auditory function in a population exposed to low-level methylmercury (MeHg) exposure from fish consumption and to mercury vapor (Hg0) from dental amalgams. We analyzed their associations with the participants hearing acuity, absolute and interwave ABR latencies, and otoacoustic emissions (distortion product/DPOAE and click evoked/CEOAE). DesignWe administered an audiometry test battery to 246 participants from the Seychelles Child Development Study (SCDS) Nutrition Cohort 1 (NC1) at 9 years of age. The test battery included standard pure-tone audiometry, tympanometry, Auditory Brainstem Responses (ABR) and Distortion Product and Click Evoked Otoacoustic Emissions (DPOAE and CEOAE) testing. We measured prenatal MeHg exposure in maternal hair and postnatal MeHg in children’s hair. We approximated prenatal Hg0 exposure using maternal amalgam surface area and postnatal Hg0 using children amalgam surface area. Complete exposure records and audiometric data were available on 210 participants and in them we analyzed the association of MeHg and Hg0 exposures with auditory outcomes using covariate-adjusted linear regression models adjusted for sex and tympanometric pressure. ResultsHg exposures were similar for both sexes. Seven of the 210 evaluable participants examined had either a mild (5) or moderate (2) hearing loss. Four had a mild monaural hearing loss and 3 had either a mild (1) or moderate (2) bilateral hearing loss. No participant had greater than a moderate hearing loss in either ear. Hg exposures were higher in participants with either a mild or moderate hearing loss, but these differences were not statistically significant. Among the 210 with complete data, neither prenatal nor postnatal MeHg nor Hg0 exposure was statistically significantly associated with any of the ABR endpoints (p > 0.05 for all 72 associations). Neither prenatal nor postnatal Hg0 exposure was associated with any of the OAE endpoints (p > 0.05). MeHg exposure was statistically associated with 6 of the 56 DPOAE endpoints (p-values between 0.0001 and 0.023), but none of the 40 CEOAE endpoints. Two of the associations occurred with prenatal MeHg exposures and 1 of those would suggest a beneficial effect. Four of the other associations occurred with postnatal MeHg exposures with only 2 found in left ears of both males and females and the other 2 in the left and right ear of females at only one frequency. ConclusionOverall, these data do not present a clear and consistent pattern to suggest that the auditory system is negatively affected by low-level methylmercury exposure due to dietary consumption of oceanic fish or mercury vapor exposure from dental amalgams.

Vestibular evoked myogenic and auditory brainstem evoked potentials in a female migraine population.

<p>The purpose&nbsp;of the present study was to evaluate ocular vestibular evoked myogenic potential (oVEMP), cervical vestibular evoked myogenic potential (cVEMP), and brainstem auditory evoked potential (BAEP) response characteristics and to understand the pathophy&shy;siology of vestibular dysfunction in female migraineurs with vertigo symptoms. We also aimed to assess the electrophysiological di&shy;&shy;agnostic significance of the VEMP respon&shy;ses in vestibular migraine (VM).&nbsp;</p>. <p>23 patients with migraine without aura (MoA), 23 patients with VM, and 20 sex-and age-matched healthy controls, a total of 66 female participants were enrolled in this study. The outcome parameters were asymmetry ratios (ARs), amplitudes of oVEMP, cVEMP, N1P1, P13N23, and the respective latencies (mean &plusmn; SD). From the BAEP graphs, absolute and interpeak interval latencies of waves were analyzed.&nbsp;</p>. <p>30.4% of the MoA group and 21.7% of the VM group had uni- or bilaterally absent cVEMP responses which were statistically significant only in the MoA group (p=0.035) in comparison to control group. Both groups displayed statistically insignificant absent or asymmetrical responses for oVEMP (13.1%). Cervical VEMP P13 and N23 latency, peak-to-peak amplitude, interaural latencies, and amplitude ARs did not show any significant difference between MoA and VM patients and healthy controls. No significant difference was detected among the three groups in the oVEMP and BAEP parameters.</p>. <p>Although absent cVEMP responses were more common in MoA and VM patients than in healthy individuals, the VEMP and BAEP test results should not be used in the differential diagnosis of VM and MoA.&nbsp;</p>.

A cross-sectional analysis to study the effects of mobile use on brainstem auditory response in young healthy male adults

Background: The intensive use of mobile phones has given rise to adverse effects concerning the potential influences of electromagnetic fields on human health. The ear, being the closest, is the direct recipient of electromagnetic radiation, thus making it the most likely affected organ. The present study assessed the effects of mobile usage on brainstem auditory responses in young healthy male adults using brainstem-evoked response audiometry. Aims and Objectives: The present study aimed to evaluate the effects of long-term repeated exposure to mobile phones on the hearing of young healthy male adults by assessing and comparing absolute wave latencies and interpeak latencies (IPLs) of brainstem auditory responses. Materials and Methods: The cross-sectional study was conducted using the RMS EMG SALUS 2C machine in the Physiology Department of SMS Medical College, Jaipur. This was an analytical type of observational study design incorporating a total of 70 young healthy male adults from SMS Medical College, Jaipur, in which Group I was using mobile for &gt;2 h/day for the duration of &gt;1 year and &lt;5 years and Group II was using mobile for &gt;2 h/day for the duration of more than 5 years. Results: The IPL I–III and I–V of the right ear of Group II was significantly prolonged (P &lt; 0.05) compared to IPL I–III and I–V of the right ear of Group I. Conclusion: This study revealed a significant prolongation of IPLs in the right ear of Group II mobile users associated with duration of usage.

Auditory function assessment in patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease is a multisystem disease with multiple comorbidities. Hearing is dependent on the cochlear functions that may be affected by oxygenation. Affection of hearing is problematic and represents a major concern that should be seriously investigated as an important comorbidity in chronic obstructive pulmonary disease patients. To assess auditory status among chronic obstructive pulmonary disease patients. The current study was carried out at Al-Azhar University Hospitals, Cairo, from 1 August 2021 to 2022, including 120 participants. In addition to the control group (60 healthy participants), there were two study groups: chronic obstructive pulmonary disease patients with respiratory failure group (30 patients) and non-respiratory failure group (30 patients). Hearing functions were studied using pure tone audiometry, and auditory brain stem response. There was statistically significant hearing impairment in chronic obstructive pulmonary disease patients in comparison to control group. The hearing impairment was more significant in chronic obstructive pulmonary disease with respiratory failure group in comparison to chronic obstructive pulmonary disease without respiratory failure group. The auditory impairment shows a negative interrelationship with oxygen tension (PaO2) and a positive interrelationship with the smoking index. Hearing affection was meaningfully higher among chronic obstructive pulmonary disease patients and more prominent in patients with respiratory failure. Hypoxia results in deterioration of pure tone audiometry and increased absolute and interpeak latencies in auditory brain stem response. At every frequency, the mean pure tone audiometry thresholds were higher for chronic obstructive pulmonary disease groups than control group albeit remaining in the mild to moderate area of hearing loss. Retro-cochlear affection was suggested among patients with chronic obstructive pulmonary disease as evidenced with the prolongation of auditory brain stem response waves latencies.

Brain stem auditory evoked potentials in type 2 diabetes mellitus patients at varying frequencies.

As per the World Health Organization, in 2005, more than 180 million people had diabetes worldwide. This figure will be more than double by 2030. Neuropathy is common and late complication of diabetes mellitus (DM). Sensory neural hearing loss which is severe at higher frequencies has been reported in Type 2 DM patients. Auditory nerve tract damage increases the latency and reduces the amplitude of the response. Evoked potential recordings evaluate the neural pathways in the central nervous system. Brainstem auditory evoked potentials (BAEP) localize anatomic structures using different waves and detect acoustic and central neuropathy (CN). Hence, brainstem evoked response of audiometry (BERA) is used widely in clinical set up. 1. To record BERA waves in normal subjects with normal blood sugar levels (hemoglobin A1C [HbA1C] <5.4. 2. To record BERA waves in Type 2 DM patients. (HbA1C >6.5). To study the BERA parameters with the normal subjects with blood sugar subjects and compare them with Type 2 DM patients. n = 30, Type 2 DM patients between the age of 35-50 years of either sex were chosen from the Diabetic Clinic of GMC, Aurangabad, Maharashtra. HbA1C test for glycemic control and BERA waves to assess CN were recorded. n = 30 normal subjects with normal blood sugar with age and sex-matched above tests were performed. Unpaired Student's t-test. Mean ± Standard deviation of the absolute latency and interpeak latency of BERA waves at 2, 4, and 6 KHz at 80 dB in Type 2 DM patients were delayed and found to be significant as compared to control group. The above study explains that if BAEP is recorded at higher frequencies like 6 KHz and at 80 dB, CN involvement can be detected earlier in diabetic patients. Hence, it is recommended to carry out BERA in diabetic patients at least once in a year.

Auditory and Vestibular Findings in Brazilian Adults Affected by COVID-19: An Exploratory Study

Introduction: The aim of the study was to describe auditory and vestibular findings in Brazilian adults after COVID-19 in a municipality from the outskirts of the São Paulo state. Methods: This was a transversal and exploratory study comprising sixteen participants infected by the SARS-CoV-2 virus, confirmed through RT-PCR detection, aged 20 to 55 years. Subjects underwent anamnesis, vestibular and auditory testing. Fisher’s exact test was used to evaluate medication use, chemical and physical exposure, and occupational risk and McNemar test was used to compare auditory and vestibular symptoms pre- and post-COVID-19. Results: Most patients were women (75%) and had been exposed to the virus over 90 days before testing (50%). 18.8% used hydroxychloroquine, 68.8% used ivermectin, and 87.5% used azithromycin to treat COVID-19. Auditory complaints were reported by 31.2% and vestibular by 18.7%. There was no statistical difference before and after the disease. Other reported symptomatology was hair loss, pain, fatigue, memory loss, difficulty to concentrate, and headache. Auditory findings were relevant in contralateral acoustic reflex, in the distortion-product otoacoustic emissions, and in the brainstem auditory evoked potential, characterizing a neurosensorial compromise. 43.74% of patients had altered vectonystagmography. When comparing both ears, no statistical relevance was found; however, when results were crossed with medication use and exposures, there was statistical relevance in the amplitude of the V wave for medications and absolute latency of the V wave to exposure to physical agents. Discussion/Conclusion: This study demonstrated auditory and vestibular findings of neurosensorial nature, considering hearing and of a peripheral vestibulopathy. As it is a study of transversal nature, it is not possible to extend results to general population; yet it may be a finding to future studies.

Comparing Auditory Brain Stem Responses and Transient Otoacoustic Emissions in Premature Infants with Auditory Developmental Delay: Evidence of Temporary Auditory Neuropathy.

Premature birth causes some permanent or temporary abnormalities in the hearing system of the newborn. Inadequate development of the central auditory nervous system and balance, as well as the delay in the formation of the nerve myelin, can be the cause of many hearing disorders, including permanent or temporary auditory neuropathy spectrum disorder (ANSD). The present study aims to identify and understand developmental delay disorder in the hearing system of infants and investigate the possibility of temporary auditory neuropathy in infants. In this comparative analytical study, twenty premature infants were randomly selected for hearing tests using auditory brainstem response and transient otoacoustic emissions at the time of discharge and three months after the first evaluation. The different components of these tests were analyzed and compared before and after developing the auditory system. The OAEs test showed a signal-to-noise ratio above six dB with appropriate amplitudes in all infants. The grand average waveform of the ABR showed a significant difference between the amplitudes of waves III and V before and after maturation in both ears (p<0.05). In addition, the absolute latency of waves, specifically III and V, showed a significant difference between the two assessment times (0.05). The present study confirmed the occurrence of temporary ANSD or delayed maturation in premature infants following the lack of complete growth and myelination of auditory nerve fibers. There is a need to determine the hearing status of premature infants by frequent examinations and prevent any unnecessary prescription of amplifications.

Change of brainstem auditory-evoked potential in vertebrobasilar transient ischemic attack patients

Background: Transient ischemic attack describes the symptoms of the nervous system which occurs due to insufficient circulation that lasts for &lt;24 h. Its clinical manifestations tend to disappear quickly and it is also considered as an indicator of stroke. Brainstem auditory-evoked potentials are responses of the brainstem by auditory stimulation. Vertebrobasilar (VB) transient ischemia can cause brainstem ischemia which can induce BAEP changes. Hence, it becomes necessary to evaluate the electrophysiological changes in VB transient ischemic attack (VBTIA) patients so that early detection of neuronal changes and prevention of full-blown stroke. Aims and Objectives: The aim of this study was to compare the changes in brainstem auditory-evoked potential in VB TIA patients with normal subject. Materials and Methods: Auditory-evoked potential was recorded in 40 patients with VBTIA and 40 normal control groups. This study was conducted at the Research Laboratory, Department of Physiology, Thanjavur Medical College, Thanjavur. Results: The absolute latency of wave V was prolonged and a reduction in amplitude of wave V was observed in patients with VBTIA and it was found to be statistically significant. Conclusion: This study is very much useful to identify the early detection of the progression of stroke in VB TIA patients. Further studies are required to evaluate the correlation between the electrophysiological parameters and progression into stroke so that preventive measures can be used to prevent early involvement of Stroke.

Study of auditory pathways in type 1 diabetes mellitus through brainstem auditory evoked potentials and contralateral acoustic reflex.

To investigate the functionalities of the neural pathways through the auditory evoked potentials of the brainstem and the contralateral stapedial acoustic reflexes in normal-hearing individuals with type 1 diabetes mellitus, in order to detect possible alterations in the central auditory pathways. This is a cross-sectional study with a comparison group and a convenience sample, consisting of 32 individuals with type 1 diabetes mellitus and 20 controls without the disease. All subjects had hearing thresholds within normal limits and type A tympanometric curves. The acoustic reflex arc and brainstem auditory potentials were investigated. Statistical analyses were performed using the SPSS 17.0. The Chi-square test, Student´s t-test, and Multiple linear regression were used. The auditory thresholds of the acoustic reflex were statistically lower in the group with the disease at frequencies of 0.5 kHz and 1.0 kHz in the left ear (p=0.01 and p=0.01, respectively). The absolute latencies III and V of the auditory potentials of the brainstem in the right ear and V in the left ear were increased in subjects with type 1 diabetes mellitus (p=0.03, p=0.02 and p=0.03, respectively). The findings suggest that subjects with type 1 diabetes mellitus are more likely to present alterations in the central auditory pathways, even with auditory thresholds within normal limits.