Brainstem Auditory Evoked Potential Test Research Articles

Recent Advances in Intraoperative Brainstem Auditory Evoked Potential Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm.

Brainstem auditory evoked potential (BAEP) testing during microvascular decompression (MVD) is very important in the treatment of hemifacial spasm (HFS). The reason for this is that the vestibulocochlear nerve is located immediately next to the facial nerve, so the vestibulocochlear nerve may be affected by manipulation during surgery. BAEP testing for detecting vestibulocochlear nerve damage has been further developed for use during surgery. In most HFS patients with normal vestibulocochlear nerves, the degree of vestibulocochlear nerve damage caused by surgery is well-reflected in the BAEP test waveforms. Therefore, real-time testing is the best way to minimize damage to the vestibulocochlear nerve. The purpose of this study was to review the most recently published BAEP test waveforms that were obtained during MVD surgery to determine the relationship between vestibulocochlear nerve damage and BAEP waveforms.

Cortical deafness as a sequel of recurrent stroke in patient with prosthetic heart valves and atrial fibrillation: a case report

BackgroundCortical deafness is an unusual occurrence caused by injury to the central auditory pathway but not to the hearing organ. This paper reports the first case of cortical deafness as a sequel of recurrent stroke in a patient with prosthetic heart valves and atrial fibrillation in Asia.Case presentationA 40-year-old man with a history of atrial fibrillation and valvular heart disease comes with weakness on the right side of the body and slurred speech. Examination showed hemiplegia with increased d-dimer and activated partial thromboplastin time. (APTT). Brain MRI showed multiple subacute infarctions in the temporal lobe. Diffusion Tensor Imaging (DTI) tractography showed no visible auditory tract. Pure tone audiogram and brainstem auditory evoked potential test was normal, but speech reception threshold test was very poor. The patient has been diagnosed with recurrent ischemic stroke with sequel cortical deafness and received anticoagulant therapy and speech therapy. The patient reported minimal subjective impairment 1 month later with no further neurological deterioration.ConclusionsA multidisciplinary clinical approach is needed in patients with cortical deafness, especially distinguishing it from other central hearing losses.

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>.

Factors Related to the Progression of Clinically Isolated Syndrome to Multiple Sclerosis: A Retrospective Study in Lithuania.

Background and Objectives: Multiple sclerosis (MS) is a demyelinating disease which usually manifests as clinically isolated syndrome (CIS). Approximately 70% of patients with CIS progress to MS. Therefore, there is a pressing need to identify the most accurate predictive factors of CIS developing into MS, some of which could be a clear clinical phenotype of early MS as well as lesions in magnetic resonance imaging (MRI), pathological findings in cerebrospinal fluid (CSF) and evoked potentials (EP) tests. The problem is of outstanding importance since early MS diagnosis and treatment prevents long-term disability. The aim of our study is to analyze the factors that could influence the progression of CIS to MS. Materials and Methods: This study is a retrospective data analysis which included patients with their primary CIS diagnosis between 1st January 2015 and 1st January 2020. The prevalence and predictive value of clinical symptoms, MRI lesions, pathological CSF and EP findings were evaluated in accordance with the final diagnosis and compared between the sexes and age groups. Results: Out of 138 CIS patients, 49 (35.5%) patients progressed to MS. MS patients were more likely to have a diminished sense of vibration and proprioception (χ2 = 9.033, p = 0.003) as well as spinal cord MRI lesions (χ2 = 7.209, p = 0.007) in comparison with the non-MS group. Positive oligoclonal bands (OCBs) in CSF (χ2 = 34.859, p ≤ 0.001) and pathological brainstem auditory evoked potential (BAEP) test findings (χ2 = 10.924, p ≤ 0.001) were more prevalent in the MS group. Diminished sense of vibration and proprioception increased the risk for developing MS by 13 times (p = 0.028), whereas positive OCBs in CSF increased the risk by 100 times (p < 0.001). MS patients that were older than 50 years were more likely to exhibit positive Babinski’s reflex (χ2 = 6.993, p = 0.03), decreased muscle strength (χ2 = 13.481, p = 0.001), ataxia (χ2 = 8.135, p = 0.017), and diminished sense of vibration and proprioception (χ2 = 7.918, p = 0.019) in comparison with both younger age groups. Conclusions: Diminished sense of vibration and proprioception, spinal cord MRI lesions, positive OCBs and pathological BAEP test findings were more common among patients that developed MS. Diminished sense of vibration and proprioception along with positive CSF OCBs are predictors of CIS progressing to MS. Older patients that develop MS have more symptoms in general, such as positive Babinski’s reflex, decreased muscle strength, ataxia, and diminished sense of vibration and proprioception.

Conversion from clinically isolated syndrome to multiple sclerosis: what paraclinical tests findings are the most characteristic?

Background. Multiple sclerosis (MS) is a chronic demyelinating disease with clinical onset usually manifesting as clinically isolated syndrome (CIS). Approximately 70% of people with CIS convert to MS. Therefore, there is a pressing need to identify the most characteristic paraclinical test findings to predict CIS conversion to MS.Aim. The aim of this study was to establish the most characteristic paraclinical test findings for the identification of CIS conversion to MS.Materials and methods. A retrospective data analysis was performed in patients diagnosed with demyelinating encephalomyelitis according to ICD-10 (International Classification of Diseases Tenth Revision), codes G37.8 (other specified demyelinating diseases of central nervous system) and G37.9 (demyelinating disease of central nervous system, unspecified). In clinical practice, these diagnoses are called CIS. The data were obtained from medical records and included findings of paraclinical tests (magnetic resonance imaging (MRI), IgG levels and oligoclonal bands (OCBs) in cerebrospinal fluid (CSF), and brainstem auditory evoked potential (BAEP)) and final diagnosis. The patients were divided into 2 groups according to the final diagnosis (MS group and non-MS group) and into 3 age groups (18-30, 30-50, &gt;50 years old). The prevalence and statistical difference of paraclinical tests were estimated between the groups. Chi-squared test was used to compare between categorical variables. Mann-Whitney U test was used to compare between the groups. The association between two quantitative variables was determined using Spearman correlation co-efficient. Results were interpreted as statistically significant when p-value &lt;0.05.Results. A total of 138 cases were included in the study. 49 patients converted to MS (35.5%), other 89 patients (64.5%) were diagnosed with other diseases than MS. Unspecified MRI lesions (χ2=4.328, p=0.037, n=40), elevated IgG levels (χ2=10.793, p=0.001, n=36), and positive OCBs in CSF (χ2=34.859, p&lt;0.001, n=30) were more prevalent in MS group compared to non-MS group. Moreover, lesions detected by the BAEP test were also more frequent among MS group (χ2=10.924, p&lt;0.001, n=17).Conclusions. The results indicate that pathological CSF findings (positive OCBs, elevated IgG levels) and prolonged BAEP latency are characteristic in patients with CIS who later progress to MS. Unspecified brain MRI lesions are also distinctive for MS patients; however, this result should be interpreted with consideration due to methodological reasons

Effectiveness of Brainstem Auditory Evoked Potentials Scoring in Evaluating Brainstem Dysfunction and Disability Among Individuals With Multiple Sclerosis.

Purpose The brainstem dysfunction in multiple sclerosis (MS) often causes significant functional impairment leading to disability. This study aims to explore modified brainstem auditory evoked potential (BAEP) scores based on the pattern of BAEP abnormalities and relate with brainstem symptoms, brainstem functional system scores (BFSS), brainstem lesions, and disability. Method Forty-five participants with relapsing-remitting MS and 45 age- and gender-matched healthy controls underwent case history assessment, otoscopic examination, pure-tone audiometry, and BAEP testing. Also, neurological examination (Expanded Disability Status Scale, FSS scales) and magnetic resonance imaging were carried out on MS participants. Patterns of BAEP abnormalities were categorized and converted to BAEP scores. Results Out of 45 participants' brainstem symptoms, BFSS > 1, brainstem lesions (magnetic resonance imaging), and BAEP abnormalities were observed in 75.6%, 42.2%, 62.2%, and 55.56% of participants, respectively. Waves V and III abnormalities were more common among MS participants and showed a significant difference from the control group in the Mann-Whitney U test. Chi-square test did not show a significant association of BAEP abnormalities with brainstem symptoms and lesions but showed significant association with BFSS. The mean and standard deviation of BAEP scores in MS participants were 1.73 + 2.37. All healthy controls showed BAEP scores of 0. BAEP scores in MS participants showed significant correlation with BFSS scores and predict Expanded Disability Status Scale scores. Conclusion BAEP scores based on the pattern of BAEP abnormality can be a valid and useful measure in evaluating brainstem functions and predicting disability in MS.

Alcoholic cerebellar degeneration: A case report

Introduction Alcohol-induced cerebellar degeneration is the commonest type of acquired toxic ataxia. The onset of the cerebellar symptoms usually occurs at middle age, with a significant history of chronic alcohol abuse. Permanent cerebellar deficits are observed among alcoholics, and they persist even with alcoholic abstinence. The cerebellum is the structure that controls the stability of the gaze, chronic cerebellar diseases and acute alcohol intoxication affect cerebellar function. Ataxia and nystagmus are neurological manifestations present in this disease. To verify vestibulocochlear disorders observed in a case of alcohol-induced cerebellar ataxia. Material and method It is a clinical case study of alcohol-induced cerebellar ataxia. The patient featured troubled walking (wide-based gait, preserved tactile sensitivity, hyperesthesia of the lower limbs, nystagmus, dysmetria, mild dysdiadochokinesia, numbness in the distal phalanges of the upper limbs, and uncoordinated movement). Results The patient evidenced bilateral hearing loss from the frequency of 3 kHz and absence of ipsilateral reflexes; magnetic resonance imaging (MRI) showed atrophy of the Cerebellar Vermis; scale for the assessment and rating of ataxia (SARA) scored 15; brainstem auditory evoked potential test (BAEP) evidenced diffused dysfunction of the auditory pathways; balance testing showed labyrinthine hypofunction with presence of bidirectional nystagmus, featuring central vestibular disorder and the falls efficacy scale (FES-1-Brazil) evidenced abnormalities. Conclusion The patient started treatment using B12 vitamin, thiamine, and physical therapy. Currently, despite reported balance improvement, he needs ambulation support. He features nystagmus, bilateral dysmetria, mild dysdiadochokinesia, continuous tinnitus in his left ear, blurred vision, and neck pain while moving it.

Hearing of neonates without risk indicators for hearing loss and use of antimalarial drugs during pregnancy: a historical cohort study in the Northern Region of Brazil

IntroductionStudies have demonstrated the ototoxic effects of antimalarial drugs in individuals who receive these drugs, but little is known regarding the toxicity of these drugs in the newborn auditory system when administered to the mother receive the drug during pregnancy. ObjectiveTo verify the incidence of hearing loss in neonates who have no other associated risk indicators, born to mothers treated for malaria during pregnancy. MethodsA retrospective, quantitative cohort study was developed at Hospital de Base Dr. Ary Pinheiro and Clínica Limiar, both located in the municipality of Porto Velho (Rondônia). The sample consisted of 527 newborns divided into two groups: exposed to antimalarials drugs during pregnancy group (n = 32) and non-exposed group (n = 495). Data collection took place from September 2014 to December 2015, through an interview with the mothers and/or guardians of the newborn, through the newborns’ and the mothers’ records, and the neonatal hearing screening database of the above-mentioned institutions. ResultsAll the neonates in the exposed group, assessed through the recording of transient otoacoustic emissions associated with the automated brainstem auditory evoked potential test, underwent neonatal hearing screening in the first examination. Among the newborns in the non-exposed group, 30 showed failure and were retested. Of these, one continued to fail and was referred for diagnosis, in whom the results showed to be within the normal range. Among the neonates of the exposed group, infection with Plasmodium vivax was the most frequent, and was similarly distributed among the gestational trimesters, and chloroquine was the most commonly used antimalarial drug treatment more often given during the third trimester; these findings did not show any influence on the audiological findings of the studied neonates. ConclusionThe present study did not identify any cases of hearing loss in neonates born to mothers who used antimalarial drugs during gestation.

The importance of central auditory evaluation in Friedreich's ataxia.

Objective To assess central auditory function in Friedreich's ataxia. Methods A cross-sectional, retrospective study was carried out. Thirty patients underwent the anamnesis, otorhinolaryngology examination, pure tone audiometry, acoustic immittance measures and brainstem auditory evoked potential (BAEP) assessments. Results The observed alterations were: 43.3% in the pure tone audiometry, bilateral in 36.7%; 56.6% in the BAEP test, bilateral in 50%; and 46.6% in the acoustic immittance test. There was a significant difference (p < 0.05) in the comparison between the tests performed. Conclusion In the audiological screening, there was a prevalence of the descending audiometric configuration at the frequency of 4kHz, and absence of the acoustic reflex at the same frequency. In the BAEP test, there was a prevalence of an increase of the latencies in waves I, III and V, and in the intervals of interpeaks I-III, I-V and III-V. In 13.3% of the patients, wave V was absent, and all waves were absent in 3.3% of patients.

The potential role of auditory evoked potentials to assess prognosis in comatose survivors from cardiac arrest

AimFew data are available on the use of brainstem auditory evoked potentials (BAEPs) in combination with other electrophysiological tools to assess prognosis of comatose survivors from cardiac arrest (CA). MethodsRetrospective analysis of data from all adult patients (>18years of age) admitted to our Dept of Intensive Care after CA over a 6-year period who were comatose (Glasgow Coma Scale <9) on admission, had been treated with targeted temperature management and had BAEP testing. We collected variables related to CA, as well as electroencephalography (EEG) findings, N20 somatosensory evoked potentials, and the presence of I, III and/or V waves on BAEP testing. Outcome was assessed at 3 months using the Cerebral Performance Categories (3–5=poor outcome). ResultsWe studied 65 patients; 48 (74%) had a poor neurological outcome. BAEP assessment was performed day 3 [3,4] after the CA. At least one of the three waves was absent bilaterally in 34 patients (52%); of these patients, 29 (85%) had a poor neurological outcome (sensitivity 60%, specificity 71%, positive predictive value [PPV] 85% and negative predictive value [NPV] 39%). Three patients (5%) had bilateral absence of all three waves, all of whom had a poor neurological outcome. ConclusionsIn this series of patients after CA, at least one of the BAEP waves was absent bilaterally in half the survivors; however, their use for prediction of poor neurological outcome remains limited.

The application value of aEEG and NBNA in the early evaluation on brain damage for full-term neonates with hyperbilirubinemia

Objective To investigate the application value of amplitude integrated electroencephalogram (aEEG) and neonatal behavioral neurological assessment(NBNA) in the early evaluation on brain damage for full-term neonates with hyperbilirubinemia. Methods From August 2015 to February 2016, 42 full-term neonates with hyperbilirubinemia were divided into two groups:subclinical bilirubin encephalopathy group and hyperbilirubinemia control group according to the results of magnetic resonance imaging(MRI), while 20 normal healthy full-term infants born in our hospital at the same time were chosen as normal control group. The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Clinic Medical College of Yangzhou University. Informed consent was obtained from each parents.The serum level of total bilirubin(TB), the score of NBNA, the abnormality rate for brainstem auditory evoked potential (BAEP) and aEEG were compared among three groups,meanwhile the correlation for these parameters were assayed. Results (1)There were significant differences in the level of UCB ,the score of NBNA, the abnormality rate of BAEP and aEEG among different groups (F=20.16, 7.12,χ2=15.18,12.23,P 0.05). (2)Of the 7 mildly abnormal aEEG cases in the subclinical bilirubin encephalopathy group, 6 mildly abnormal and 1 moderately abnormal were found in BAEP test. All of the 9 severely abnormal aEEG cases in the subclinical bilirubin encephalopathy group were found 1 moderately abnormal and 8 severely/very severely abnormal of BAEP. By linear correlation analysis,the abnormality degree of aEEG was positively correlation with BAEP (γ=0.806,P=0.032). (3)22 cases of subclinical bilirubin encephalopathy group inclued 16 abnormal aEEG cases (72.73%) and 21abnormal aEEG with NBNA cases (95.45%) respectively,there were statistically significant differences (χ2=4.08,P<0.05). Conclusion aEEG combining with NBNA may be an reference indicator for early evaluation on brain damage in full-term neonates with hyperbilirubinemia. It has great clinical important value and can be worth popularizing. Key words: aEEG; NBNA; Neonate; Hyperbilirubinemia; Brain damage

Central auditory processing in patients with spinocerebellar ataxia

BackgroundAutosomal dominant spinocerebellar ataxias (SCAs) are a group of rare and heterogeneous neurodegenerative diseases characterized by the presence of progressive cerebellar ataxia. Although the symptomatology of SCAs is well known, information regarding central auditory functioning in these patients is lacking. Therefore, we assessed the central auditory processing disorders (CAPD) in patients with different subtypes of SCA. MethodsIn a retrospective cross-sectional study, we subjected 43 patients with SCAs to otorhinolaryngological, audiological, Brainstem Auditory Evoked Potential (BAEP) and acoustic immittance evaluations as well as CAPD tests, namely the Standard Spondaic Word (SSW) and the Random Gap Detection Test (RGDT). ResultsMost patients (83.7%) reported an imbalance when walking; many reported difficulty speaking (48.8%), dizziness (41.8%), and dysphagia (39.5%). In the audiometric test, 14/43 patients (32.5%) presented alterations, including 4/12 patients with SCA3 (33.3%), 1/8 patients with SCA2 (12.5%), 1/1 patient with SCA4 (100%), 1/1 patient with SCA6 (100%), 1/1 patient with SCA7 (100%), 3/6 patients with SCA10 (50%), and 3/14 patients with an undetermined type of SCA (21.4%). In the BAEP test, 20/43 patients (46.5%) presented alterations (11.6% na orelha esquerda e 34.9% bilateralmente), including 7/12 patients with SCA3 (58.3%), 5/8 patients with SCA2 (62.5%), 1/1 patient with SCA4 (100%), 1/1 patient with SCA6 (100%), 1/1 patient with SCA7 (100%), 4/6 patients with SCA10 (66.7%), and 2/14 patients with an undetermined type of SCA (14.2%). In the SSW, 22/40 patients (55%) presented alterations (2.5% in the right ear, 15% in the left ear, and 37.5% bilaterally), including 6/10 patients (60%) with SCA3, 3/8 (37.5%) with SCA2, 1/1 (100%) with SCA4, 1/1 (100%) with SCA6, 1/1 (100%) with SCA7, 4/5 (80%) with SCA10, and 8/14 (57.1%) with an undetermined type SCA. For the RGDT, 30/40 patients (75%) presented alterations, including 8/10 (80%) with SCA3, 6/8 (75%) with SCA2, 1/1 (100%) with SCA4, 1/1 (100%) with SCA6, 1/1 (100%) with SCA7, 4/5 (80%) with SCA10, and 9/14 (64.3%) with an undetermined type of SCA. In immittance testing, 19/43 patients (44.1%) presented alterations, including 6/12 (50%) with SCA3, 4/8 (50%) with SCA2, 1/1 (100%) with SCA4, 1/1 (100%) with SCA6, 1/1 (100%) with SCA7, 2/6 (33.3%) with SCA10, and 4/14 (28.6%) with an undetermined type of SCA. ConclusionsA majority of patients exhibited SSW test deficits, with a predominance of bilateralism, and three-fourths had impaired RGDT performance, pointing to difficulties with binaural integration and temporal resolution. Assessment of CAPD is important for therapeutic follow ups in patients with SCA.

Auditory dysfunction in patients with type 2 diabetes mellitus with poor versus good glycemic control

Abstract Auditory functions among patients with type 2 diabetes mellitus (DM) are controversial regarding cochlear or neural changes and the relationship between these changes and serum level of glycosylated hemoglobin (HbA 1c%). The aim of the study was to investigate auditory dysfunctions in type 2 DM patients with poor versus good glycemic control. The present study was conducted on three groups: two diabetic groups with poor and good glycemic control (n = 18 and 14, respectively) based on serum HbA 1c% and one healthy control group (n = 30) matched with age, sex, and BMI. All participants were subjected to clinical assessment, audiometry, brainstem auditory evoked potential (BAEP), and evoked acoustic emissions transient evoked otoacoustic emissions and distortion product otoacoustic emissions (TEOAEs and DPOAEs). Diabetic patients with poor glycemic control had significantly elevated hearing thresholds compared with other groups at low and high frequencies in audiometry (P < 0.01 and P < 0.001). They showed significantly prolonged absolute latency in wave I and interpeak latency (III-V) in the BAEP test compared with other groups (P < 0.001). DM patients with poor glycemic control had significantly low amplitudes at all frequencies in the TEOAE test, as well as at high frequencies (4 and 6 kHz) on the DPOAE test, compared with other groups (P < 0.001 and P < 0.05, respectively). There were significant correlations between HbA 1c% and interpeak latency III-V (r = 0.340, P = 0.004) on the one hand and overall response of TEOAE amplitude (r = −0.471; P = 0.000) on the other. Diabetic patients with poor glycemic control had worse auditory dysfunctions on both cochlear and neural findings.

Clinical features of hearing damages caused by bacterial meningitis in children

Objective To explore the prognosis and risk factors of the hearing damages caused by bacterial meningitis in children. Methods A systematic retrospective analysis was carryed out based on their clinical data, the brainstem auditory evoked potential (BAEP) test and follow-up evaluation in 63 pediatric patients diagnosed with bacterial meningitis from Jun. 2011 to May 2013 in Urumqi Children's Hospital. The duration from onset to the first BAEP test, CRP results, ethnics, genders, age white blood cell count, protein and glucose levels in cerebros pinal fluid(CSF) were compared between the BAEP abnormal group and BAEP normal group. Results Fifty children were detected by BAEP. The hearing damage at single or both ears with different severity were found in 22 cases, so the incidence of abnormanity was 44%. Six cases in which were suffered from auditory pathway disorders at a single ear, including 4 cases in left ears, and 2 cases in right ears, while 16 cases were in both ears. Among them, peripheral auditory pathway damages with hearing abnormalities were found in 21 cases. Central auditory pathway damage of brainstem was found only in 1 case. Sixteen cases with BAEP abnormalities were followed up in 1-6 months. Four ears of 3 cases with severe hea-ring damages were not improved and eventually became paratonic sensorineural hearing loss. There was no difference of the duration from onset to the first BAEP test, CRP results, ethnics and genders between the BAEP abnormal group and BAEP normal group (all P>0.05). However, in BAEP abnormal group, the cases of white blood cell count ≥1000×106/L (18 cases), protein≥1.5 g/L(15 cases), glucose levels≤1.0 mmol/L (11 cases), in CSF age≤1 year old (18 cases) were significantly higher those in BAEP normal group (14 cases, 9 cases, 5 cases, 14 cases, respectively)(χ2=5.14, 6.42, 5.85, 5.41, all P<0.05). Conclusions Hearing damages are common complications of the bacterial meningitis in children, and severe hearing damages may difficult to recover in the early stage. The risk factors of hearing damages caused by the bacterial meningitis in children are age, white blood cell count, protein and glucose levels in CSF. It is quite important to finish the early BAEP tests and follow up at regular intervals for bocterial meningitis in chindren. Key words: Bacterial meningitis; Brainstem auditory evoked potential; Hearing damage; Clinical features; Child

Further Study is Needed to Assess Ototoxicity from Organophosphates and Paraquat

I read with interest the study conducted by Jayasinghe et al. entitled, “Effects of Deliberate Ingestion of Organophosphate or Paraquat on Brain Stem Auditory-Evoked Potentials” published in your journal [1]. The authors concluded there were no significant lesions in the auditory pathway in organophosphate (OP)- or paraquat (PQ)-poisoned patients compared to the matched controls; they also speculated the generation of reactive oxygen species within the perilymphatic space following ingestion of OP or PQ may not be enough to cause lesions in the auditory pathway. However, inclusion into their study and subsequent analysis did not account for severity of poisoning by OP or PQ, and it was not clear how symptomatic patients were at first brainstem auditory evoked potential (BAEP) testing (1 week after exposure) or at repeat testing. If poisoning was not severe enough, that could account for no significant lesions in the auditory pathway. Further study is needed to follow-up this interesting pilot study: BAEP test should be performed on admission in patients with OP or PQ poisoning and BAEP testing should be repeated every other day in the first week to understand better how OP and PQ poisoning may or may not be associated with ototoxicity.

Beyond herniation

Few data are available on the use of brainstem auditory evoked potentials (BAEPs) in combination with other electrophysiological tools to assess prognosis of comatose survivors from cardiac arrest (CA).Retrospective analysis of data from all adult patients (>18 years of age) admitted to our Dept of Intensive Care after CA over a 6-year period who were comatose (Glasgow Coma Scale <9) on admission, had been treated with targeted temperature management and had BAEP testing. We collected variables related to CA, as well as electroencephalography (EEG) findings, N20 somatosensory evoked potentials, and the presence of I, III and/or V waves on BAEP testing. Outcome was assessed at 3 months using the Cerebral Performance Categories (3–5 = poor outcome).We studied 65 patients; 48 (74%) had a poor neurological outcome. BAEP assessment was performed day 3 [3,4] after the CA. At least one of the three waves was absent bilaterally in 34 patients (52%); of these patients, 29 (85%) had a poor neurological outcome (sensitivity 60%, specificity 71%, positive predictive value [PPV] 85% and negative predictive value [NPV] 39%). Three patients (5%) had bilateral absence of all three waves, all of whom had a poor neurological outcome.In this series of patients after CA, at least one of the BAEP waves was absent bilaterally in half the survivors; however, their use for prediction of poor neurological outcome remains limited.

Auditory processing in children and adolescents in situations of risk and vulnerability.

Children and adolescents who live in situations of social vulnerability present a series of health problems. Nonetheless, affirmations that sensory and cognitive abnormalities are present are a matter of controversy. The aim of this study was to investigate aspects to auditory processing, through applying the brainstem auditory evoked potential (BAEP) and behavioral auditory processing tests to children living on the streets, and comparison with a control group. Cross-sectional study in the Laboratory of Auditory Processing, School of Medicine, Universidade de São Paulo. The auditory processing tests were applied to a group of 27 individuals, subdivided into 11 children (7 to 10 years old) and 16 adolescents (11 to 16 years old), of both sexes, in situations of social vulnerability, compared with an age-matched control group of 10 children and 11 adolescents without complaints. The BAEP test was also applied to investigate the integrity of the auditory pathway. For both children and adolescents, there were significant differences between the study and control groups in most of the tests applied, with significantly worse performance in the study group, except in the pediatric speech intelligibility test. Only one child had an abnormal result in the BAEP test. The results showed that the study group (children and adolescents) presented poor performance in the behavioral auditory processing tests, despite their unaltered auditory brainstem pathways, as shown by their normal results in the BAEP test.

Prematurity and Parental Expectations: Too Early and Now Too Much

Hami is a 3-year-old boy who is a former premature 25-week infant with a birth weight of 1 pound 9 ounces. He had a relatively smooth Neonatal Intensive Care Unit (NICU) course; he required intubation for 1 month and went home on room air. He had a left Grade I intraventricular hemorrhage that was resolved by 2 months of life. He had 7 blood transfusions for anemia over the first 3 months of life. A brainstem auditory evoked potential test was normal at hospital discharge, and he showed no evidence of retinopathy of prematurity. He never had seizure activity.He was discharged to home at 3 months where he did well and thrived on a high calorie formula. He walked at 17 months and spoke his first words at 2 years. He was enrolled in Early Intervention at the time of discharge from hospital; monthly home visits were increased to weekly visits by an early childhood educator at 12 months. When he was 12 months, he was enrolled in a family day care with 4 other children younger than 3 years. Hami's language development was slow; at 2.5 years of age, he was beginning to make 2 word combinations. Early intervention services were increased to include an additional hour of speech and language therapy as well as a play group.Hami's mother is 33 years old, and this is her first child. She worked as an accounting assistant, but she was able to be home with Hami for the first year of his life. She returned to full-time work on his first birthday. Hami's father is 35 years old and works for the national electrical grid as a manager. They are not married but have lived together for the last 5 years. Dad works evenings and cares for Hami from 4 to 6 pm after childcare; mom returns from work at 6 pm. Dad leaves for work at 7 pm and works till 2 am. Their relationship has been strained by the child care demands, their work schedules, and Hami's developmental progress.Hami's primary care pediatrician specializes in children with complex medical problems. The parents express concern at the 3-year-old visit that Hami's language is not progressing as it should be. They are concerned that he is much more active than the other 3 year olds in his child care setting. Early intervention has initiated the transition process to a public school placement, and the parents are very concerned that he is too young, too active, and too much of a handful to be "in the big public school." What would you do next?

The value of brainstem auditory evoked potential and lower limb short latency somatosensory evoked potential for predicting delayed encephalopathy after acute carbon monoxide poisoning

Objective To observe the changes of brainstem auditory evoked potential (BAEP) and lower limb short latency somatosensory evoked potential ( SLSEP) in acute carbon monoxide poisoning patients and explore the predictive value of BAEP and SLSEP for delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Methods Sixty-six acute CO poisoning patients was divided into a DEACMP group and a non-DEACMP group according to their symptoms. At the same time, 60 healthy subjects were included in the control group. BAEP and lower limb SLSEP dynamic testing were conducted at different time points. Results The abnormal rates in the first test of BAEP and lower limb SLSEP in the acute CO poisoning patients were 31.8% and 68.2% respectively.The BAEP results in the acute stage and later in the DEACMP group were comparable to those of the non-DEACMP group and the normal control group. Interpeak latency of Ⅰ-Ⅲ was not significantly different, but the remaining indices were significantly longer. Compared to the control group, the lower limb SLSEP readings in the acute DEACMP group and the non-DEACMP group were significantly longer. Compared to the non-DEACMP group and the control group, the SLSEP results of the DEACMP group were significantly extended. The specificity index of the BAEP predicted DEACMP up to 85.7% , significantly more than SLSEP testing. Conclusions Early detection of BAEP can help predict DEACMP. This finding should be promulgated and applied. Key words: Brainstem auditory evoked potential; Lower limb somatosensory evoked potential; Acute carbon monoxide poisoning; Delayed encephalopathy; Prediction

Brainstem Auditory Evoked Potentials–A Review and Modified Studies in Healthy Subjects

The authors review the brainstem auditory evoked potential (BAEP), and present studies on 40 healthy subjects. In addition to the conventional click evoked BAEP, three modified BAEP examinations were performed. The modified BAEP tests include a 1,000 Hz tone-burst BAEP, and more rapid rate binaural click and 1,000 Hz tone-burst BAEPs-each of the last two studies performed at four diminishing moderate intensities. In addition to the usual parameters, the authors examined the Wave V to Vn interpeak latency, and stimulus intensity versus Wave V latency and amplitude functions in the rapid rate binaural studies. Studies were also repeated on healthy subjects in a dependant head position in an attempt to increase intracranial pressure. Discussion centers on the BAEP, its current utility in medicine, unique neurophysiology, and literature support that the above modifications could increase the practicality of the test in patients at risk with intracranial lesions and perhaps improve the feasibility for real-time continuous or frequent monitoring in the future.