Brainstem Electric Response Audiometry Research Articles

Clinical characteristics, recurrent etiological analysis of recurrent purulent meningitis in children and its treatment strategy

Objective To investigate the clinical characteristics and causes of recurrent purulent meningitis and its treatment. Methods The clinical data of 36 children with recurrent purulent meningitis were analyzed retrospectively at Tianjin Children′s Hospital from 1995 to 2014.Based on the underlying illness, the following examinations were done respectively: brainstem electric response audi-ometry(BERA), temporal bone computed tomography, head magnetic resonance imaging(MRI), spinal core MRI, and blood immunoglobulin, etc. Results There were 24 boys and 12 girls involved in this study.The age of the initial onset in these patients ranged from 20 months old to 15 years old, with the average age of 5 year and 9 months old.There were 2 to 7 episodes in these cases.The etiology was identified: 19 cases (52.78%) with congenital anatomical abnormalities, 12 cases of congenital inner ear malformation with cerebrospinal fluid(CSF) leakage, 1 case of ear-nose CSF leakage, 6 cases of pilonidal sinus.Fifteen cases (41.67%) had anatomical abnormalities, 12 cases had head and facial trauma, 1 case had nasal polyps surgery, 1 case (2.77%) had a history of chronic mastoiditis, and 1 case had a history of cochlear implant surgery; 1 case of congenital humoral immunodeficiency disease X-linked agammaglobulinemia-free; 1 case (2.77%) had humoral immunodeficiency disease.The anti-infection treatment was adopted in the acute-phase and then CSF rhinorrhea repair, CSF otorrhea, cerebrospinal fluid leakage, repair of the inner ear, pilonidal sinus resection, supplementary intravenous immunoglobulin around once every 3 months was given respectively in the restoration-phase.Thirty-three cases revealed no recurrence up to 8 months till 10 years follow-up, 3 cases lost-to-follow-up. Conclusions The recurrent purulent meningitis is a serious infectious disease of the central nervous system, which may result in disabled condition even life-threatening.In order to avoid purulent meningitis recurrence, the corresponding treatment should be chosen according to different causes. Key words: Purulent meningitis; Recurrent; Etiology; Remedies; Child

Use of auditory evoked potentials in screening children for integrity of auditory pathways

Background: Auditory evoked potentials (AEP) can be used to assess the integrity of auditory pathway for early hearing loss and planning rehabilitative procedures. It is noninvasive and can be performed in uncooperative and difficult-to-test children under mild sedation. Aims and Objective: To determine the hearing threshold to assess the integrity of auditory pathway in children of suspected hearing loss and to find out the importance of AEP where other screening tests cannot be performed. Materials and Methods: This retrospective study was conducted in Acharya Vinoba Bhave Rural Hospital and Department of Physiology, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, Maharashtra, India. It included 80 children of suspected hearing loss in the age group of 1–12 years, referred under Sarva Shiksha Abhiyan program. Brainstem auditory responses were recorded in these children using multichannel polyrite system. Silver chloride disk electrodes were used on standard scalp locations. Results: Our results showed that 40 of 80 children were having definite mild-to-severe hearing loss. In nearly 50% children hearing loss was confirmed by AEP. In remaining 40 children, brainstem electric response audiometry showed normal responses indicating normal hearing. Of 80 suspected children, 20 were either uncooperative or not fit for any other screening tests for hearing. AEP showed that of these 20 children, 12 (15% of total), were having sensorineural loss that helped them in seeking treatment. Conclusion: Our results concluded that AEP at present is one of the most useful tools for assessment of integrity of auditory pathway and detection of early hearing loss, and it can greatly contribute in its management. It can definitely be used in screening for deafness and assessing the nature of hearing loss, particularly in patients who cannot perform in the usual audiometric procedures. It can also be used to assess the maturity of central nervous system in newborn and young children.

High Incidence of GJB2 Mutations During Screening of Newborns for Hearing Loss in Austria

The aim of the present study was to evaluate gap junction protein beta2 (GJB2) genetic testing within a national neonate screening program for hearing loss (HL) in a European population. Neonatal cases of nonsyndromic HL (N = 21) were identified by postpartal otoacoustic emissions (OAE) and brain stem electric response audiometry (BERA) analysis. GJB2 testing was performed by direct sequencing. Mutations in GJB2 were found in 15 of 21 children (71.4%) identified by neonatal audiological screening. The 35delG mutation in GJB2 was found homozygous in 10 cases (47.6%) and also as a clear cause of HL as the heterozygous alterations 35delG/del311-324 and 35delG/L90P. In a single case, L90P/R143Q was also identified as a cause of HL. In 3 HL cases that were not identifiable during initial OAE testing, homozygous 35delG and 35delG/R184P defined the genetic basis for HL in 2 cases, whereas one case had wild-type GJB2. Our findings of the high mutation rate in the Austrian population, especially in neonates identified during the newborn screening program, confirm the importance of screening for mutations in GJB2.

Wirkung elektromagnetischer Felder des GSM-Mobilfunksystems auf auditives und vestibuläres Labyrinth und Hirnstamm

It is the subject of this study to investigate the biological effect of the HF radiation produced by the Global System for Mobile Communications-( GSM)-mobile phone on the inner ear with its sensors of the vestibular and auditive systems. Thermographic investigations made on various model materials and on the human temporal bone should show whether mobile phone does induce any increases of temperature which would lead to a relevant stimulus for the auditive and vestibular system or not. We carried out video-nystagmographic recordings of 13 subjects, brainstem electric response audiometry of 24 ears, and recordings of distorsion products of otoacoustic emissions of 20 ears. All tests were made with and without a mobile phone in use. The data was then analyzed for variation patterns in the functional parameters of the hearing and balance system that are subject to the (non)existence of electromagnetic radiation from the mobile phone. The thermographic investigations suggest that the mobile phone does not induce any increases of temperature which would lead to a relevant stimulus for the auditive and vestibular system. Video-nystagmographic recordings under field effect do not furnish any indication of vestibular reactions generated by field effects. Compared with the recording without field, the brainstem electric response audiometry under field effect did not reveal any changes of the parameters investigated, i. e. absolute latency of the peaks I, III, V and the interpeak latency between the peaks I and V. The distorsion products of otoacoustic emissions do not indicate, comparing the three measuring situations, i. e. before field effect, pulsed field and continuous field, any possible impacts of the HF field on the spectrum or levels of emissions for none of the probands. The investigations made show that the electromagnetic fields generated in using the mobile phone do not have an effect on the inner ear and auditive system to the colliculus inferior in the brainstem and on the vestibular receptors in the inner ear and the vestibular system.

Chromosom-1q-Syndrom und Innenohrschwerhörigkeit: ein ungewöhnlicher Fall

The interstitial deletion of chromosome 1q is a disease of rare incidence, which might be hereditary or caused by spontaneous changes within the chromosome respectively. The phenotype in most cases is based on the loss of macrochromosomal material within the long arm of chromosome 1. The characteristics of this syndrome include pre- and postnatal growth retardation, severe psychomotor retardation, microbrachycephaly, sparse fine scalp hair and eyebrows, deformity of skull with cleft of lips and palate, scoliosis, small hands and feet hernias, genital defects, clinodactyly of the fifth fingers and campylodactyly. Other morphological characteristics that have been reported are mainly kidney and cardiac abnormalities. The number of symptoms are related to the loss of genetic material. To our knowledge this is the first description of a patient with interstitial deletion of chromosome 1 (q23-q31). We report an eleven year old boy with interstitial deletion of chromosome 1(q23-q31). In addition to the known skeletal, orofacial disorders, hypothrophia and retardation we discovered a unilateral high-graded and contralateral middle-graded hearing loss. In infants with chromosome 1q syndrome adequate diagnostic procedures have to be employed to unveil sensineural hearing losses that might be overseen because of mental retardation. In particular a brainstem electric response audiometry should be considered for early diagnosis and treatment of a possible hearing-loss.

A pilot case control follow-up study on hearing in children treated with tobramycin in the newborn period

Objective: To assess the occurrence of hearing loss in children due to neonatal exposure to long courses of tobramycin and/or high tobramycin serum concentrations. Methods: This was a pilot case–control study in 3–4-year old children. Data on tobramycin administration were abstracted from the patient files of an earlier study. Patients exposed in the neonatal period to either long courses (>7 days) or high serum concentrations of tobramycin constituted the study group. The control group consisted of patients without tobramycin exposure. Patients were matched for other risk factor according to criteria of the joint committee on infant hearing. All patients underwent the following investigations: otoscopy and pneumatic otoscopy, followed by impedance audiometry, to exclude middle ear effusion. Click-evoked oto-acoustic emissions (ce-OAE) as well as distortion product oto-acoustic emissions (dp-OAE), tested at f2 frequencies ranging from 1 to 10 kHz, were measured to assess hearing. All patients with abnormal ce-OAE results underwent brainstem electric response audiometry (BERA) as well. Since aminoglycoside ototoxicity is usually bilateral, results were compared per patient and not per ear. Results: A total of 29 patients were tested. Eleven patients were excluded due to middle ear effusion. Data for 18 patients were analyzed. In the tobramycin treated group ( n=9) both ce-OAE and dp-OAE (at all tested frequencies) were not detectable in six ears of three patients. All other patients had normal ce-OAE's as well as normal dp-OAE's in this frequency range. Difference between the tobramycin treated and control group for OAE as well as dp-OAE showed a trend ( P=0.08). In all three patients with undetectable emissions BERA confirmed a cochlear loss of 60–70 dB at 3 kHz in both ears. These three patients had the longest total exposure to tobramycin: 20–24 days and 84–92 mg/kg, respectively. No relation to either peak or trough serum concentrations could be detected. Conclusion: There was no statistical relation between hearing loss and tobramycin exposure, probably due to sample size. Our results do indicate a need for a case–control follow-up study of hearing in neonates exposed to long courses of aminoglycosides.

Differential effects of glucocorticoids on human auditory perception

It is assumed that glucocorticoids and mineralocorticoids, the hormones produced by the adrenal cortex, act as modulators of central nervous functions in addition to their well known role in endocrine stress responses. More specifically, it has been suggested that adrenal corticoids cause changes in sensory thresholds. In two double-blind crossover studies we evaluated auditory perception in healthy volunteers after treatment with hydrocortisone, dexamethasone, and the respective placebos. Stapedial reflexes, pure tone and speech audiograms, and brainstem electric response audiometry served as the dependent variables. As circadian changes in the density and occupancy of the brain corticosteroid receptors have been postulated, we performed Study I in the morning and Study II in the evening. Treatment effects clearly varied with time of day. A differential effect of the two corticoids occurred on contralateral stapedial reflexes. These results parallel results obtained with gustatory stimuli, and suggest that glucocorticoids modulate sensory perception across modalities.

Brain stem electric response audiometry in neonates with hyperbilirubinemia.

Auditory evoked responses using BERA were studied in 30 newborn babies with plasma bilirubin > or = 15 mgm/dl and repeated after treatment of neonatal jaundice with bilirubin levels of < or = 10 mgm/dl. A few jaundiced babies (16.5%) showed absent BERA response at the initial/subsequent examination. After treatment, 3/30 babies showed absent wave form responses and 2 of these were clinically kernicteric. Jaundiced babies had prolonged wave peak latencies and inter peak latencies. Treated babies showed a tendency towards recovery in their BERA responses which were however not complete. Total plasma bilirubin value at the time of BERA examination and mean maximal bilirubin values had no correlation with the incidence and degree of BERA abnormalities.

The masked threshold to noise ratio in brainstem electric response audiometry: assessment of the conductive loss component by bone-conducted masking.

The aim of this study was to assess the conductive loss component (CLC) by brainstem electric response audiometry. A bone-conducted noise was used to mask out the response to a conventional air-conducted click stimulus. The difference between the levels of the click and the noise is defined as the masked threshold to noise ratio (MTNR). This MTNR was determined for 21 normal ears (MTNR = -13 +/- 5 dB). The increase in MTNR compared to this normative value is a measure of the CLC. For 10 ears with an artificially induced purely conductive loss, the increase in MTNR is in good agreement with the results of conventional pure-tone and brainstem electric response audiometry.

Prognostic Validity of Brainstem Electric Response Audiometry in Infants of a Neonatal Intensive Care Unit

This study compared the results of brainstem electric response audiometry (BERA) in infants of a neonatal intensive care unit to those obtained on the same children with pure-tone audiometry at 3 years of age. Six hundred children were initially tested in infancy, and complete follow-up information was obtained on 333. In 297 (89%) the BERA results accurately predicted the hearing status at the age of 3 years. Twenty-nine (9%) of the discrepancies were related to conductive hearing losses: 17 patients with a conductive hearing loss in the first few months of life had normal hearing at 3 years, and 12 patients normal in infancy had a conductive loss at 3 years. Two patients evaluated as a sensorineural hearing loss by BERA had normal hearing. These may have been due to a conductive loss. Six patients assessed as normal by BERA had significant hearing losses at the age of 3 years. Five of these had normal hearing at one frequency between 1,000 and 4,000 Hz. The sixth may have developed a sensorineural hearing loss after birth.

Evaluation of Electrocochleographic Audiogram Determination in Infants

An evaluation was made of results of electrocochleography (ECoG) in a group of 75 children, tested during the last four years in the ENT department of the Leiden University Hospital. Eleven years was taken as the upper age limit; 79% of our group were younger than three and a half years. In only 60% of the children the cause of the hearing loss was clarified. In this group maternal rubella followed by meningitis and retardation were the most frequent cases of deafness. Cochlear microphonics (CM) could be measured in all the children. Examples are given of cochlear responses of children belonging to 6 different threshold categories. The responses of the largest category (56 children) with the highest loss (larger than 80 dB) were very abnormal. For the categories with less hearing loss the ECoG was not restricted to threshold determination and the origin of the hearing loss could be demonstrated, while a contribution of conduction loss could be derived from a horizontal shift of the latency-intensity function to higher intensity levels. The potentialities and limitations of ECoG and brainstem electric response audiometry (BERA) for threshold determination are discussed, particularly against the background of the time consumption of both procedures and the invasive character of ECoG.

Acoustic Value of Brain-stem Audiometry in Infancy

At the 1989 meeting of the Triological Society in San Francisco, Calif, Drs Peter W. Alberti, Martyn L. Hyde, and Krista Riko, Toronto, Canada, presented a study regarding the validity of brain-stem audiometry in high-risk infants. The study group consisted of 731 high-risk infants comparing early brain-stem audiometry with results of later behavioral testing done at ages 3 to 5 years. Children were initially selected for evaluation from a high-risk registry and underwent brain-stem electric response audiometry at 3 to 4 months of age. Approximately 5% had moderate-to-severe hearing losses. The infants who had conductive losses due to middle ear effusion were excluded from the study. When a threshold for sensorineural loss of 40 dB or worse was utilized, brain-stem electric response audiometry was 94% sensitive, with a 96% specificity. For lesser degrees of hearing loss, the testing was considerably less sensitive, and the authors recommend that the 40-dB criterion

A prospective study of the application of click evoked oto-acoustic emissions and brainstem electric response audiometry to detect hearing impairment at birth : J.C. Stevens, H. Webb, J. Hutchinson a, J. Connell a, M.F. Smith b and J.T. Buffin a Department of Medical Physics and Clinical Engineering Royal Hallamshire Hospital, Sheffield, S10 2JF, aDeparment of Audiology, Sheffield Childrens Hospital and

A prospective study of the application of click evoked oto-acoustic emissions and brainstem electric response audiometry to detect hearing impairment at birth : J.C. Stevens, H. Webb, J. Hutchinson a, J. Connell a, M.F. Smith b and J.T. Buffin a Department of Medical Physics and Clinical Engineering Royal Hallamshire Hospital, Sheffield, S10 2JF, aDeparment of Audiology, Sheffield Childrens Hospital and

Auditory investigations in hypothyroidism.

Twenty patients with thyroprivic hypothyroidism with a mean age of 34.8 years (range: 15-50 years) were investigated. Peripheral/central functions of the auditory system were assessed in the hypothyroid state and they were re-evaluated in the euthyroid state after treatment with levothyroxine. The mean observation period for re-evaluation was 3.7 months (range 3-7 months). Sixteen patients with hypothyroidism (80%) demonstrated hearing loss when compared with randomly selected age- and sex-matched normal subjects. Twelve of the hypothyroid patients had sensorineural hearing loss and 4 had mixed loss. Special hearing tests revealed a cochlear type of hearing loss. The tympanogram curve was of Type B in one ear of each of the 4 patients. Brainstem electric response audiometry showed prolonged, absolute latency of wave V and interpeak latencies I-III and I-V. The amplitudes of waves I, II and V were reduced. Following treatment with levothyroxine a statistically significant improvement in hearing thresholds was observed by pure-tone audiometry. Tympanogram curves returned to normal in 3 out of 4 patients. Brainstem electric response parameters did not show significant reversibility to normalcy following treatment. The results of auditory investigations suggest a causal relationship between hypothyroidism and hearing loss. The site of lesion in the auditory system is probably at several levels, viz. in the middle ear, and at cochlear and retrocochlear sites.

ERA bei retrokochleären Hörstörungen*

The intensive clinical use of Electric Response Audiometry (ERA) has recently improved the diagnosis of sensorineural hearing loss. The Auditory Evoked Potentials (AEP) allow a precise topodiagnosis of the whole auditory system. However, specific limitations of the different potentials (cochlear, neural, brainstem, thalamic, cortical) have to be considered to avoid an overestimation of ERA. Based on the author's own material of more than 3500 recordings, most cases of a retrocochlear hearing loss are located at the auditory nerve and the brainstem. Therefore, brainstem electric response audiometry (BERA) and electrocochleography (ECoG) are the two most important methods of ERA. Typical Brainstem AEP (BAEP) features of retrocochlear disorders are shown. They are of different diagnostic value. A prolongation of the central conduction time or a break down of the later BAEP, both unequivocal signs of a retrocochlear lesion, were found in only 62 per cent of 100 cases of acoustic neuroma. However, diagnostic sensitivity can be improved to 96 per cent by additional use of ECoG and electrical promontory testing of the excitability of the auditory nerve. This value cannot be attained by any other audiometric test. These results show that BERA and ECoG are essential screening methods of high sensitivity in the differential diagnosis of sensorineural hearing loss. Additional values for diagnostic specificity and efficacy are also given in comparison with a group of patients initially suspected of having a cerebellopontine angle tumour. These values exceed those of conventional audiometric tests by far. Therefore, BERA and ECoG are reliable predictors of a retrocochlear lesion and can be judged as the best indicators for a CT scan or magnetic resonance imaging at present.

Brainstem electric-response audiometry in infants of a neonatal intensive care unit.

Brainstem electric-response audiometry was used to assess the auditory function of 600 infants from a neonatal intensive care unit. Two groups of children were tested, one group as inpatients prior to discharge with a mean age at test of 39.4 weeks and one group as outpatients with a mean age at test of 55.4 weeks. Our results indicate that testing infants when they are older will reduce the incidence of failure on the initial evaluation and will reduce the identification of transient hearing losses which resolve spontaneously. Our results also indicate that a threshold of 30 dB nHL or less is probably normal and that some infants with a threshold of 40 dB nHL at first test require otological or audiological management.

Issues in early identification of hearing loss.

In a general hospital, an early detection research program based on a high risk register and brain stem electric response audiometry (BERA) using click and frequency-specific stimuli identified 631 at-risk neonates from the well baby nursery and the neonatal intensive care nursery (ICN). BERA tests were done before discharge and four months later; comparison of outcomes revealed substantial discrepancies. From the follow-up test, 51 cases of mild to severe hearing loss were identified. Experience from the research program has raised some issues relevant for establishment of service programs. Evaluation of all babies (general nursery and ICN) is justified on the basis of yield but is resource consuming; strategies for minimizing work load are discussed. Risk factor criterion levels affect case loading and yield. Frequency-specific BERA identifies cases which would not be detected by click stimuli and which raise management questions. Deferral of testing to four months is feasible and desirable.

The Crib-O-Gram in the NICU

This study evaluated the Crib-O-Gram as a screening test for hearing loss in NICU infants using Brain Stem Electric Response Audiometry (BERA) as the standard. Two Crib-O-Gram tests were administered to 280 babies within 48 hours of BERA testing. An additional 26 babies received BERA and one Crib-O-Gram test. Correlation coefficients for the two Crib-O-Gram scalar scores were calculated separately for a group of preterm (31 to 37 weeks) and a group of full term and older (38 to 54 weeks) infants, with values of 0.36 and 0.52, respectively. This indicates that the Crib-O-Gram has poor reliability for a screening test, particularly for preterm babies. Approximately one-third of babies with normal BERA thresholds failed Crib-O-Gram screening. The identification of hearing loss by Crib-O-Gram increased with the severity of the loss. Crib-O-Gram was able to identify moderately severe hearing losses in full term and older babies.

Brainstem electric audiometry: is routine sedation necessary?

Decreased EEG and EMG waves in sedated adults might produce more sensitive and better defined brainstem electric response. This was investigated by comparing the brainstem electric response to click stimulation in 10 adult volunteers before and during sedation with chloral hydrate. The results showed that there is no increase in sensitivity of the test in cooperative and relaxed adult subjects. The definition of wave I did not improve after sedation. It is therefore concluded that routine sedation is not advantageous in brainstem electric response audiometry in cooperative subjects.

An evaluation of BERA for hearing screening in high-risk neonates.

Brain stem electric response audiometry (BERA) is evaluated for early detection of hearing loss in high-risk newborns selected from a general hospital population. They receive screening BERA in the nursery and detailed frequency-specific BERA in the Audiology clinic, just before discharge. Three months later, testing is repeated and recommendations are made. From 1364 assessments, 321 at-risk babies were identified; 234 received predischarge tests, and 200 had follow-up tests. Screening BERA with 40 dB nHL clicks is appropriate in the nursery. Screening sensitivity is good, and only 8% of babies failed. Several of these had mild hearing loss, resolving in the first trimester. Follow-up BERA confirmed hearing loss in 8 babies. Parental compliance is high, and the program is well-accepted. In conjunction with the high-risk register, BERA is useful both for screening and for quantitative audiometry in the infant.