Brainstem Auditory Evoked Potentials Research Articles

Peripheral and brainstem auditory evaluation in post-COVID-19 individuals

PurposeThe purpose of this study was to investigate the peripheral and central auditory pathways in adult individuals after COVID-19 infection. MethodA total of 44 individuals aged between 19 and 58 years, of both genders, post-COVID-19 infection, confirmed by serological tests, with no previous hearing complaints and no risk factors for hearing loss, were assessed. All the participants underwent the following procedures: pure tone audiometry, logoaudiometry, immitanciometry, and Brainstem Auditory Evoked Potentials (BAEP), in addition to answering a questionnaire about auditory symptoms. ResultsThirteen individuals (29.5 %) had some hearing threshold impairment, mainly sensorineural hearing loss. In the BAEP, 18 individuals (40.9 %) presented longer latencies, mainly in waves III and V. According to the questionnaire answers, 3 individuals (9.1 %) reported worsened hearing and 7 (15.9 %) tinnitus that emerged after the infection. As for the use of ototoxic drugs during treatment, 7 individuals (15.9 %) reported their use, of which 5 showed abnormalities in peripheral and/or central auditory assessments. ConclusionConsidering the self-reported hearing complaints after COVID-19 infection and the high rate of abnormalities found in both peripheral and central audiological assessments, it is suggested that the new COVID-19 may compromise the auditory system. Due to the many variables involved in this study, the results should be considered with caution. However, it is essential that audiological evaluations are carried out on post-COVID-19 patients in order to assess the effects of the infection in the short, medium, and long term. Future longitudinal investigations are important for a better understanding of the auditory consequences of COVID-19.

A multidisciplinary non-invasive approach to monitor response to intravenous immunoglobulin treatment in neurodegenerative Langerhans cell histiocytosis: a real-world study.

Early detection and treatment of neurodegenerative Langerhans cell histiocytosis (ND-LCH) have been suggested to prevent neurodegenerative progression. The aim of the study is to validate a standardized multidisciplinary diagnostic work-up to monitor the intravenous immunoglobulins (IVIG) treatment response and the natural course of the disease in untreated patients. Patients with abnormal somatosensory evoked potentials (SEPs) received monthly 0.5 g/kg IVIG. The diagnostic protocol included structural 3T MRI, neurological examination, brainstem auditory evoked potentials (BAEPs) and SEPs. Twenty-two patients were followed for 5.2 years (median) from the first MRI evidence of ND-LCH. Eleven patients received IVIG for 1.7 years (median). At treatment start neurological examination was abnormal in 10 patients, of whom two had severe clinical impairment and four had abnormal BAEPs. At last follow-up, 1/11 remained stable and 7/11 improved, while worsening of neurological or neurophysiological findings, or both, occurred in 3/11. Risk factors for worsening were a severe clinical or MRI ND-LCH at treatment initiation and prolonged exposure to LCH. Of the 11 untreated patients, none improved and three worsened. Using a standardized diagnostic protocol, we demonstrated that IVIG treatment can lead to clinical stabilization or improvement in all pauci-symptomatic patients with an MRI grading of less than 4.

Late-onset of Labyrinthine Dysfunction in Chronic Brucella-induced Encephalitis

Brucellosis, caused by Brucella, dominates in the Middle East. Acute or chronic brucellosis can involve any organ system, and the involvement of the central nervous system leads to encephalitis, called neurobrucellosis (NB). We report a rare case from north India where a variant of Brucella caused NB led to progressive labyrinthine dysfunction; who developed vertigo, disequilibrium, and gradual progressive sensorineural (SN) hearing loss. Audiological tests pure-tone audiometry (PTA), otoacoustic emissions (OAE), stapedial muscle reflexes, auditory evoked brainstem responses (ABR), and vestibular evoked myogenic potentials (VEMPs) were conducted on the patients. PTA showed a bilateral profound SN hearing loss, an absent OAE, and ABR suggestive of cochlear dysfunction. The cervical and ocular VEMP showed delayed n1 and p1 latencies, suggesting superior and inferior nerve branch involvement. Vertigo or disequilibrium and SN hearing loss can be the late-onset manifestations of labyrinthine dysfunction in chronic Brucella-induced encephalitis.

An Unusual Case of a Central Pontine Myelinolysis Associated with Primary Splenic Diffuse Large B-cell Lymphoma.

A 54-year-old woman with persistent fatigue and a high fever presented with central pontine myelinolysis (CPM) on brain imaging, despite the absence of neurological symptoms. The patient had a slightly low serum sodium concentration. Further investigation led to a diagnosis of primary splenic diffuse large B-cell lymphoma (PS-DLBCL). Brainstem auditory-evoked potentials (BAEP) indicated minor abnormalities. CPM was successfully resolved after splenectomy and immunochemotherapy. This is the first reported case of CPM in a patient with PS-DLBCL confirmed by a pathological diagnosis following splenectomy and BAEP-detected abnormalities that improved with immunochemotherapy.

A Comparative Study on Brainstem Auditory-Evoked Response between Dogs and Cats

A Comparative Study on Brainstem Auditory-Evoked Response between Dogs and Cats

Evoked potential response in patients with idiopathic Parkinson’s disease and atypical parkinsonian syndromes: A comparative study

Patients with idiopathic Parkinson’s disease (IPD) and atypical parkinsonian syndromes (APSs) suffer from a range of disorders, especially in balance and locomotion, which necessitate visual, auditory, and somatosensory inputs. In this study, IPD patients, APS patients, and healthy controls (HCs) (n = 50 per group) underwent a series of assessments for visual evoked potentials (VEP), brainstem auditory evoked response (BAER), and short-latency somatosensory evoked potentials (SSEP). Results showed that VEP P100 latency was prolonged in multiple system atrophy-cerebellar type (MSA-C), multiple system atrophy-parkinsonian type (MSA-P), and corticobasal ganglionic degeneration (CBD) patients. The latency of peaks III and V was prolonged in IPD, MSA-C, dementia with Lewy bodies (DLB), and Parkinson’s disease dementia (PDD). BAER I-III and I-V interpeak latency were prolonged in IPD, DLB, and PDD, whereas BAER I-III, III-V, and I-V interpeak latencies were increased and the V/I amplitude ratio was decreased in MSA-C. The central sensory conduction time (N20-N13) was increased in MSA-P and MSA-C in SSEP. IPD patients had prolonged VEP P100 latency (P < 0.001), lower VEP N75-P100 amplitude (P < 0.001), prolonged BAER I, II, II, IV, V peak latencies (P < 0.001), I-III, I-V interpeak latencies (P < 0.001), lower BAER V/I amplitude ratio (P < 0.001), and prolonged SSEP N13, N20, central sensory conduction time (N20-N13) (P < 0.001) than HCs. IPD patients also had prolonged BAER I, II, II, IV, V peak latencies (P < 0.001), prolonged I-III, I-V interpeak latencies (P < 0.001), and shorter SSEP N13, N20, central sensory conduction time (N20-N13) (P < 0.001) than APS patients. Moreover, APS patients had prolonged VEP P100 and N145 latencies (P < 0.001) and decreased N75-N145 amplitude (P < 0.001) compared to HCs. APS patients also had prolonged BAER II, II, IV, V peak latencies (P < 0.001), prolonged I-III, III-V, I-V interpeak latencies (P < 0.001), decreased V/I amplitude ratio, and prolonged SSEP N13, N20, central sensory conduction time (N20-N13) (P < 0.001) than HCs. Postural instability and gait disorder (PIGD) IPD had significantly prolonged BAER III, V peak latencies (P < 0.05), and prolonged III-V interpeak latencies (P < 0.05) compared to tremor-dominant IPD. Overall, the IPD and APS patients had significant VEP, BAER, and SSEP abnormalities of demyelination and axonal variety in the visual, auditory, and somatosensory pathways. The changes were also correlated with the disease duration and severity. Although the diseases are predominantly motor disorders with significant non-motor components, these electrophysiological abnormalities might open a new avenue to assess the non-motor symptoms.

The efficacy and safety of transcutaneous auricular vagus nerve stimulation for patients with minimally conscious state: a sham-controlled randomized double-blind clinical trial.

Transcutaneous auricular vagus nerve stimulation (taVNS) has emerged as a potentially effective neuromodulation technique for addressing neurological disorders, including disorders of consciousness. Expanding upon our prior clinical study, which demonstrated the superior effectiveness of a 4-week taVNS treatment in patients with minimally conscious state (MCS) compared to those in a vegetative state/unresponsive wakefulness state, the aim of this investigation was to evaluate the safety and therapeutic efficacy of taVNS in individuals with MCS through a sham-controlled randomized double-blind clinical trial. A cohort of 50 adult patients (male = 33, female = 17) diagnosed with a MCS were randomly assigned to either the active taVNS (N = 25) or sham taVNS (N = 25) groups. The treatment period lasted for 4 weeks, followed by an 8-week follow-up period. The Coma Recovery Scale-Revised (CRS-R) and Glasgow Coma Scale (GCS) were administered at baseline and weekly during the initial 4 weeks. Additionally, the Disability Rating Scale (DRS) was used to assess the patients' functional abilities via telephone at week 12. Furthermore, various neurophysiological measures, including electroencephalogram (EEG), upper-limb somatosensory evoked potentials (USEP), brainstem auditory evoked potentials (BAEP), and P300 event-related potentials (P300), were employed to monitor changes in brain activity and neural conduction pathways. The scores for the active taVNS group in the CRS-R and GCS showed greater improvement over time compared to the sham taVNS group (CRS-R: 1-week, Z = -1.248, p = 0.212; 2-week, Z = -1.090, p = 0.276; 3-week, Z = -2.017, p = 0.044; 4-week, Z = -2.267, p = 0.023. GCS: 1-week, Z = -1.325, p = 0.185; 2-week, Z = -1.245, p = 0.213; 3-week, Z = -1.848, p = 0.065; 4-week, Z = -1.990, p = 0.047). Additionally, the EEG, USEP, BAEP, and P300 also demonstrated significant improvement in the active taVNS group compared to the sham taVNS group at week 4 (EEG, Z = -2.086, p = 0.037; USEP, Z = -2.014, p = 0.044; BAEP, Z = -2.298, p = 0.022; P300 amplitude, Z = -1.974, p = 0.049; P300 latency, t = 2.275, p = 0.027). Subgroup analysis revealed that patients with MCS derived greater benefits from receiving taVNS treatment earlier (CRS-R, Disease duration ≤ 1-month, mean difference = 8.50, 95% CI = [2.22, 14.78], p = 0.027; GCS, Disease duration ≤ 1-month, mean difference = 3.58, 95% CI = [0.14, 7.03], p = 0.044). By week 12, the active taVNS group exhibited lower Disability Rating Scale (DRS) scores compared to the sham taVNS group (Z = -2.105, p = 0.035), indicating a more favorable prognosis for MCS patients who underwent taVNS. Furthermore, no significant adverse events related to taVNS were observed during treatment. The findings of this study suggest that taVNS may serve as a potentially effective and safe intervention for facilitating the restoration of consciousness in individuals diagnosed with MCS. This therapeutic approach appears to enhance cerebral functioning and optimize neural conduction pathways. http://www.chictr.org.cn, Identifier ChiCTR2200066629.

Neuroprotective Effects of Artificial Cerebrospinal Fluid: Analysis of Brainstem Auditory-Evoked Potential Monitoring During Microvascular Decompression in 117 Consecutive Patients.

To study the efficacy of irrigation with artificial cerebrospinal fluid (aCSF) for protection of cranial nerves during surgery; the time required for recovery of brainstem auditory-evoked potentials (BAEPs) that would reflect cochlear function was analyzed in comparison with that for saline irrigation. This retrospective study included 117 consecutive patients (95 women, mean age 51.5 ± 11.4 year) who underwent microvascular decompression for hemifacial spasm. During surgery, BAEPs were monitored to avoid damage to the auditory pathways. When a delayed latency of >1 ms or a decrease in amplitude of >50% was detected in BAEP wave V, surgical maneuvers were halted, and the operative field was irrigated with saline or aCSF. Saline was used for irrigation in 58 patients and aCSF in the other 59. The time required for BAEP recovery at the first halt in each patient was analyzed, and the results were compared between the groups. Surgical procedures were interrupted because of BAEP latency delays or decreases in amplitude in 51 of the patients in the saline group and 54 in the aCSF group. In both groups, the latencies and amplitudes recovered significantly with time and both recovered earlier after aCSF irrigation than after saline irrigation. Hearing outcome was not significantly different between 2 groups. aCSF is effective for protection of cochlear nerve and promotes recovery from transient dysfunction during surgery. The protective effect may be attributed to multiple factors including conditioned pH, electrolyte composition, glucose, and microelements, such as magnesium and phosphate.

Histological Reaction in the Round Window Membrane after Cochlear Implant Insertion in Nonhuman Primates

Introduction: The primary objective of this article was to determine if any histological alterations occur in the round window (RW) and adjacent anatomical structures of an animal model with normal hearing when a cochlear implant (CI) electrode array is inserted. Furthermore, this article aims to relate these histological alterations to the auditory changes generated. Methods: Cochlear implantation was performed, following the principles of minimally traumatic surgery (MTS), in 15 ears of nonhuman primates (Macaca fascicularis) (Mf) with normal hearing. Auditory brainstem-evoked potentials (ABR) using clicks and tones were used prior to surgery and during a 6-month follow-up period. Histological evaluation was carried out, analyzing the position of the electrode array with respect to the round window membrane (RWM), its percentage of occupation and integrity, the presence of intracochlear damage, and the tissue reaction provoked, the latter of which was quantified in the temporal bones. Results: Surgery was performed on all 15 ears without relevant incidences. Regarding histology, the electrode array in the RW of all ears presented a lateral position with respect to the modiolus. No lesions affecting the integrity of the RW were observed. The mean value of the array’s occupation in the RW was 25%. Tissue reaction, in the form of fibrosis, was observed in all ears and more intensely in the trans-RWM and post-RWM areas. In all ears, the electrodes remained on the scala tympani. No profound hearing impairment was recorded in any ear, being the mean loss of 25.4 dB when comparing presurgical thresholds with those collected 6 months after implantation in ABR click and 24.4 dB in ABR tone burst. Conclusions: The animal model and Hybrid L-14 (HL14) electrode array were optimal for implementing a surgical technique similar to that routinely performed on humans. Mild histological alterations were observed in the round window membrane and adjacent anatomical structures from the insertion of a cochlear implant electrode array. Following the minimally invasive technique, levels of hearing preservation were satisfactory, reaching a pre-post difference of 25.4 dB in the ABR click and 24.4 dB for a high-frequency tone burst. Complete hearing impairment was not observed in either ear. Correlation between the severity of histological alterations and hearing changes recorded in the ABR studies was observed.

Study of the peripheral and central auditory pathways in patients with mucopolysaccharidosis

ObjectiveTo investigate the peripheral and central auditory pathways in mucopolysaccharidosis (MPS) individuals. MethodThe research sample comprised 15 individuals (one female and 14 males), aged 8 to 46 years. The following procedures were used: medical history survey, otoscopy, speech and pure-tone threshold audiometry, acoustic immittance measures, and central auditory pathway assessment with brainstem auditory evoked potentials (BAEP) and long-latency auditory evoked potentials (LLAEP). ResultsThe pure-tone audiometry identified hearing loss in 13 individuals, and more than 90 % of the hearing loss was sensorineural. The degree of hearing loss was between mild to moderately severe with descendent configuration. Type A tympanogram predominated, and acoustic reflexes were present according to the types and degrees of hearing loss. Among the individuals with abnormal BAEP, longer wave III and V absolute latencies were the main findings. In addition, the unilateral absence of wave I was observed in two cases. In the LLAEP, longer latencies were observed in 14 individuals, and the most impaired components were the P1 and P3 in children and adolescents and the P2, N2 and P3 in adult individuals. ConclusionThe peripheral auditory pathway assessment revealed a predominantly sensorineural hearing loss, affecting mainly high frequencies, and in the central pathway was observed abnormal brainstem and cortical auditory processing in individuals with MPS.

Frequency of hearing loss in children with cerebral palsy and parents’ perception regarding their child’s hearing.

Objective: To determine frequency of hearing loss in cerebral palsy (CP) children and perception of child’s hearing and brain evoked response auditory (BERA) / brainstem auditory evoked potential (BAEP) results in CP patients. Study Design: Cross-sectional study. Setting: Department of Pediatric Neurology, Liaquat National Hospital, Karachi. Period: January 2022 to December 2022. Material & Methods: The parents of all the CP children having cerebral palsy and who were nor assessed for hearing screening at birth (newborn hearing screening) were included. In child neurology clinic, parents were interviewed for the perception of the hearing of the child. Parental perception, CP type and the BERA results were recorded. Results: Total 102 patients were studied with median age of 27.9 (IQR= 17 – 48) months. Majority of the patients were normally delivered (n=59, 57.8%). Nearly quarter of them underwent neonatal screening (n=22, 21.6%). Majority of mothers (n=85, 83.3%) and father (n=80, 78.4%) had perception of hearing. BERA test was normal for 44 (43.1%) children. Age was significantly higher among patients with abnormal results. Frequency mothers’ perception of normal hearing was higher in abnormal BERA result. Frequency of difficult speech was higher in patients with abnormal BERA results. Conclusion: The frequency of hearing loss was high among children with CP. Frequency of mothers’ perception of their CP child’s normal hearing was higher when compared to the father’s perception.

Brainstem auditory evoked potentials in microvascular decompression for hemifacial spasm: A prospective study

ObjectiveThe aim of this prospective study is to identify the factors influencing postoperative hearing loss (HL) and explore effective strategies for reducing postoperative hearing complications following microvascular decompression (MVD) for hemifacial spasm (HFS). MethodsFrom January 2018 to January 2023, we enrolled a total of 55 patients who underwent MVD for HFS at our institution. Intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) was conducted in all surgeries, beginning from the induction of general anesthesia and continuing until skin closure. Prior to surgery and one month after, pure-tone audiometry (PTA) evaluations were performed to evaluate HL. We conducted an analysis to identify factors that influenced postoperative HL. Our examination focused on the occurrence of postoperative HL, considering changes in BAEPs, and we evaluated the diagnostic accuracy of significant warning criteria. ResultsIn this study, a total of 55 patients (37 women and 18 men) with a mean age of 52.5 ± 13.4 years (range 24–80) were included. Among them, 5 patients (9.1 %) experienced postoperative HL. The variations in other risk factors based on the pattern of HL were not statistically significant (p > 0.05), whereas surgical experience showed significance (p = 0.028). Notably, the group of patients who showed wave V loss in intraoperative BAEPs was found to be significantly associated with postoperative HL. ConclusionSurgical experience is a factor influencing postoperative HL. Intraoperative changes in BAEPs, particularly loss of wave V, were found to be a significant indicator of poorer recovery of hearing capacity after MVD for HFS.

Subclinical neural hearing alterations in school children with type 1 diabetes mellitus

Background and objectivesEvidence has shown a cause-and-effect relationship between type 1 diabetes mellitus and auditory and cognitive dysfunctions. This study aimed to investigate the effect of type 1 diabetes mellitus (T1DM) on central auditory and cognitive functions in school-age children and adolescents. MethodsThe study sample consisted of 101 children and adolescents, 50 with T1DM, of both sexes, aged between 7 and 18 years. All participants were selected for a structured interview on hearing, behavioral, and cognitive health and assessment of brainstem auditory evoked potentials (BAEP) and event-related potentials (P300). ResultsSignificant differences were observed in memory (p=0.002) and attention (p=0.021) complaints between participants with and without T1DM. In the BAEP responses, there were differences between wave III latencies in the right (p=0.017) and left (p=0.019) ears and in wave V latencies in the left ear (p=0.001) between the evaluated groups. In addition, there was an association between BAEP findings and metabolic control in the T1DM group in the left ear in waves III (p=0.006) and V (p=0.005) and in the right ear in wave V (p=0.026). No differences were observed in the latencies of P300 between the evaluated groups. ConclusionThis study demonstrated the existence of a subclinical finding in the central auditory pathway, offering an increased risk for retrocollear alterations, which may be a consequence of poor metabolic control.

Acoustic differences in tinnitus between noise-induced and non-noise-induced hearing loss

Background Tinnitus, the perception of sound without external stimuli, varies across hearing loss types. The present study compared the acoustic characteristics of tinnitus in patients with noise-induced hearing loss (NIHL) and in those with hearing loss unrelated to noise exposure. Objective This study compared the acoustic characteristics of tinnitus in patients with noise-induced and non-noise-induced hearing loss. Methods A total of 403 patients with tinnitus were divided into those with noise-induced and non-noise-induced hearing loss. Patients were evaluated by pure tone audiometry (PTA), tinnitogram, transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and auditory brainstem evoked response (ABR) tests. Results Patients with NIHL exhibited significantly higher hearing thresholds across all frequencies (125–8000 Hz) (p < .05) and reported significantly higher tinnitus intensity (p < .05). Otoacoustic emission tests showed that response rates were significantly lower (p < .05), and ABR tests found that latency periods were significantly more prolonged (p < .05), in patients with NIHL. Conclusions Tinnitus differs acoustically between patients with NIHL and those with non-noise-induced hearing loss, with specific patterns of intensity and auditory responses. These findings emphasize the need for tailoring the management of tinnitus according to the underlying type of hearing loss.

Patogenesis of tinnitus in patients with post-COVID syndrome - preliminary report.

&lt;b&gt;&lt;br&gt;Introduction:&lt;/b&gt; Similarly to hearing loss and dizziness, tinnitus is a frequently reported complication of COVID-19 and remains the subject of numerous scientific reports. However, the exact impact of SARS-CoV-2 on the pathophysiology of tinnitus observed in post-COVID syndrome remains unclear. One suspected cause behind the development of vestibulocochlear symptoms is the inflammation of neural tissue triggered by SARS-CoV-2 infection.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Aim:&lt;/b&gt; The aim of this study was to analyze the results of Brainstem Auditory Evoked Potentials (BAEP) in the context of tinnitus development among patients diagnosed with post-COVID syndrome.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Material and methods:&lt;/b&gt; This retrospective study involved the analysis of BAEP test results of patients admitted to the Audiology Clinic of the Military Institute of Medicine at the National Research Institute and diagnosed with the post-COVID syndrome. The study compared the average latency values of waves I, II, III, IV, V, and intervals I-III, III-V, I-V. The statistical analysis of the obtained data was performed.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Results:&lt;/b&gt; Out of 18 patients (9 female, 9 male) with an average age of 54.22 years (9.65) diagnosed with post-COVID syndrome, tinnitus was identified in 5 individuals (27.78%). A statistically significant increase in wave V latency (5.98 vs. 5.63 [ms]; P &lt; 0.05) and interval III-V (1.99 vs. 1.71 [ms]; P&lt;0.05) was observed between the groups of patients with and without tinnitus.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Discussion:&lt;/b&gt; Study results analyzing BAEP changes in patients with post-COVID syndrome in the context of tinnitus are insufficient in current literature. The only available report linking post-COVID syndrome with sensorineural hearing loss demonstrated a statistically significant increase in latency values of waves III, V, and an increase in intervals I-III, III-V.&lt;/br&gt; &lt;b&gt;&lt;br&gt;Conclusions:&lt;/b&gt; Tinnitus in patients suffering from post-COVID syndrome may be related to prolonged conduction of nerve impulses within the brainstem auditory pathway. Detailed pathophysiology of these changes requires further research.&lt;/br&gt.

Auditory central pathways in children and adolescents with multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory demyelinating disease. Auditory evoked potential studies have demonstrated conduction and neural processing deficits in adults with MS, but little is known about the electrophysiological responses in children and adolescents. to evaluate the central auditory pathway with brainstem auditory evoked potentials (BAEP) and long-latency auditory evoked potentials (LLAEP) in children and adolescents with MS. The study comprised 17 individuals with MS, of both sexes, aged 9 to 18 years, and 17 healthy volunteers, matched for age and sex. All individuals had normal hearing and no middle ear impairments. They were assessed with click-BAEP and LLAEP through oddball paradigm and tone-burst stimuli. Abnormal responses were observed in 60% of electrophysiologic assessments of individuals with MS. In BAEP, 58.82% of MS patients had abnormal responses, with longer wave V latency and therefore longer III-V and I-V interpeak latencies than healthy volunteers. In LLAEP, 52.94% of MS patients had abnormal responses. Although statistical differences were found only in P2-N2 amplitude, MS patients had longer latencies and smaller amplitudes than healthy volunteers in all components. Children and adolescents with MS had abnormal BAEP responses, with delayed neural conduction between the cochlear nucleus and the lateral lemniscus. Also, abnormal LLAEP results suggest a decrease in neural processing speed and auditory sensory discrimination response.

Modified universal new-born hearing screening: Practical approach for developing world (Georgean experience).

Analysis of newborn hearing screening (NBS) outcomes and proposing a modified strategy for better performance of NBS in developing world. Descriptive (retrospective and prospective) study. A total of 8412 newborns/neonates were subjected to risk factor assessment followed by a set of subjective (behavioral audiometry: BoA) and objective (OAE: otoacoustic emissions, ABR: auditory brainstem-evoked responses) hearing-screening in different combinations. DPOAE (primary objective tool) was undertaken in 2565 cases. Predictive value of risk factors on deafness was statistically analysed along with affectivity of objective, subjective and questionnaire-based screening tools. Amongst 8412 babies, 45.5% were 'at risk' (major 36.41%, minor 9.17%). The OAE was abnormal in 299 cases (11.6% of 2565 & 3.5% in 8412). The abnormal OAE rate in prospective cases was 3.5% while in retrospective cases that underwent initial screening with BoA was 41%. A significant correlation was seen with consanguinity, high blood pressure, NICU stay>5 days, low birth weight, neonatal jaundice, delayed birth cry, pre-mature status, birth asphyxia and maternal excessive vomiting, while regression models of OAE outcome (sensitivity 99%, accuracy 89%) revealed highest predictive value for the initial 3 factors. BoA-screening revealed a sensitivity of 72.6%, and negative predictive value of 42.4%. Also a perfect correlation was evident between OAE-ABR, OAE-BoA and ABR-BoA. A subjective NBS screening through questionnaire-based-risk-assessment and modified-BoA followed by selective referral for objective assessment is more practical and focussed approach for poor resourced countries that is likely to screen a larger population.

Subclinical neural hearing alterations in school children with type 1 diabetes mellitus

Background and objectivesEvidence has shown a cause-and-effect relationship between type 1 diabetes mellitus and auditory and cognitive dysfunctions. This study aimed to investigate the effect of type 1 diabetes mellitus (T1DM) on central auditory and cognitive functions in school-age children and adolescents. MethodsThe study sample consisted of 101 children and adolescents, 50 with T1DM, of both sexes, aged between 7 and 18 years. All participants were selected for a structured interview on hearing, behavioral, and cognitive health and assessment of brainstem auditory evoked potentials (BAEP) and event-related potentials (P300). ResultsSignificant differences were observed in memory (p=0.002) and attention (p=0.021) complaints between participants with and without T1DM. In the BAEP responses, there were differences between wave III latencies in the right (p=0.017) and left (p=0.019) ears and in wave V latencies in the left ear (p=0.001) between the evaluated groups. In addition, there was an association between BAEP findings and metabolic control in the T1DM group in the left ear in waves III (p=0.006) and V (p=0.005) and in the right ear in wave V (p=0.026). No differences were observed in the latencies of P300 between the evaluated groups. ConclusionThis study demonstrated the existence of a subclinical finding in the central auditory pathway, offering an increased risk for retrocollear alterations, which may be a consequence of poor metabolic control.

Benefits of intervention in the Central Auditory Nervous System in individuals with Neurofibromatosis Type 1.

To verify the effectiveness of acoustically controlled auditory training in individuals with Neurofibromatosis Type 1. The sample consisted of individuals with Neurofibromatosis Type 1, randomly distributed into two groups, making up the intervention group: individuals undergoing formal auditory training; and the comparison group: individuals who were not submitted to the intervention. Behavioral assessment of central auditory processing and electrophysiological evaluation, composed by Brainstem Auditory Evoked Potential and Long Latency-P300 Auditory Evoked Potential, were evaluated in three moments of evaluations: initial evaluation, reevaluation and after four months of reevaluation and comparing the performance between the groups. Better performances in central auditory processing were observed after the formal auditory training in the intervention group with significant differences between the evaluations and performance maintenance four months after the end of the training. Significant differences were observed between the groups in the evaluations after the intervention. The electrophysiological evaluation shows unsystematic variation in the short latency potentials and changes in the long latency potentials with the appearance of the P3 wave after the intervention. The behavioral and electrophysiological evaluation in group that was not submitted to the intervention demonstrated that there is no improvement without the intervention, with deterioration of performance. Significant differences were observed in the behavioral and electrophysiological evaluations, in favor of the group submitted to formal auditory training. Formal auditory training is effective in rehabilitation in individuals with Neurofibromatosis Type 1. Neurofibromatosis 1; Hearing Disorders; Auditory Perceptual Disorders; Acoustic Stimulation; Evoked Potentials, Auditory.

A Comparative Study of the Brainstem Auditory-Evoked Response during Medetomidine, Propofol and Propofol-Isoflurane Anesthesia in Dogs

A Comparative Study of the Brainstem Auditory-Evoked Response during Medetomidine, Propofol and Propofol-Isoflurane Anesthesia in Dogs