Brainstem Auditory Evoked Potentials Research Articles

Comparison of the sedative and cardiovascular effects of medetomidine and medetomidine-vatinoxan, combined with butorphanol, in pediatric dogs undergoing brainstem auditory-evoked response testing

Comparison of the sedative and cardiovascular effects of medetomidine and medetomidine-vatinoxan, combined with butorphanol, in pediatric dogs undergoing brainstem auditory-evoked response testing

Beyond the cochlea: exploring the multifaceted nature of hearing loss in primary mitochondrial diseases

Abstract Primary mitochondrial diseases, with diverse systemic manifestations, often present with auditory impairments due to mitochondrial dysfunction. This study provides an in-depth exploration of auditory deficits in primary mitochondrial diseases, highlighting the impact of various pathogenic variants on both cochlea and neural/central auditory functions. An observational study involving 72 adults with primary mitochondrial diseases was conducted. Participants underwent extensive audiological evaluations including Pure-Tone Audiometry, Tympanometry, Acoustic Reflex Thresholds, Quick Speech-in-Noise Test, Listening in Spatialized Noise-Sentences test, Auditory-evoked Brainstem Responses, and Distortion Product Otoacoustic Emissions. Multivariate Analysis of Covariance and logistic regression analyses assessed the influence of various pathogenic DNA variants, accounting for age, cognitive status via the Montreal Cognitive Assessment, and disease severity through the Newcastle Mitochondrial Disease Adult Scale. Participants with the pathogenic m.3243A>G/T variants (m.3243A>G n=40; m.3243A>T n=1) exhibited significant elevations in Pure-Tone Audiometry thresholds, especially at high frequencies, suggesting cochlea involvement. Notably, the Listening in Spatialized Noise-Sentences test showed significant spatial processing deficits in the m.3243A>G/T group, possibly indicating a unique mutation-specific impact on central auditory processing. Auditory-evoked Brainstem Responses results highlighted a higher likelihood of auditory brainstem response abnormalities in this group, further substantiating neural/central auditory pathway involvement. This study emphasises the heterogeneous nature of hearing impairment in primary mitochondrial diseases, with a genotype-phenotype correlation, particularly in the m.3243A>G/T group. These insights advocate for personalised, genotype-specific auditory assessments and targeted management strategies. Conventional hearing aids and cochlear implants are ineffective for those with central auditory dysfunctions related to mitochondrial mutations. There is an urgent need for innovative rehabilitation strategies catering for both cochlear and neural/central auditory pathways.

Brainstem auditory evoked responses: Objective hearing threshold assessment in Holstein cows.

Animal audiology utilizes brainstem auditory evoked responses (BAER) as a non-invasive tool to assess hearing in animals, including Holstein dairy cows. Understanding cows' auditory capabilities is critical for their welfare, especially given their exposure to farm noise. This study provides preliminary normative BAER data for Holstein cows by focusing on absolute and interpeak wave latencies. The objective is to assess the impact of farm noise and expand audiologists' practice scope. Ten Holstein cows were tested using monoaural broadband click stimuli with contralateral masking. Earphones with foam ear tips were used to minimize environmental noise interference. The BAER responses were recorded via subdermal needle electrodes placed at standardized locations on the cows' heads. The data were analysed using descriptive statistics to determine auditory thresholds and wave latencies. The cows exhibited auditory thresholds at 90 dB SPL (55 dB nHL). Detailed wave and interpeak latencies were recorded at intensities from 85 to 105 dB SPL. At 90 dB SPL, the average latency for wave V was 5.17 ms, marking the auditory threshold for Holstein cows. These findings provide key insights into the auditory sensitivity of Holstein cows, highlighting BAER's potential for monitoring auditory health and evaluating the effects of noise pollution on animal welfare. This research underscores the value of integrating animal audiology into the audiologist's scope, ultimately enhancing both animal welfare and farming sustainability.Contribution:This study adds to the limited literature on farm animal auditory health and suggests strategies to improve welfare through better auditory management.

Intraoperative neuromonitoring in Chiari I malformation surgery: a systematic review and meta-analysis.

Chiari Malformation Type I (CMI) is a prevalent neurosurgical condition characterized by the descent of cerebellar tonsils below the foramen magnum. Surgery, aimed at reducing symptomatology and syrinx size, presents risks, making intraoperative neuromonitoring (IONM) a potentially vital tool. Despite its widespread use in cervical spine surgery, the utility of IONM in CMI surgery remains controversial, with concerns over increased operative time, cost, restricted anesthetic techniques and tongue lacerations. This systematic review and meta-analysis followed the Cochrane Group standards and PRISMA framework. It encompassed an extensive search through PubMed, Embase, and Web of Science up to December 2023, focusing on clinical and surgical outcomes of IONM in CMI surgery. Primary outcomes included the use of various IONM techniques, complication rates, clinical improvement, reoperation, and mortality. The review, registered at PROSPERO (CRD42024498996), included both prospective and retrospective studies, with rigorous selection and data extraction processes. Statistical analysis was conducted using R software. The review included 16 studies, comprising 1358 patients. It revealed that IONM techniques predominantly involved somatosensory evoked potentials (SSEPs), followed by motor evoked potentials (MEPs) and Brainstem auditory evoked potentials (BAEPs). The estimated risk of complications with IONM was 6% (95% CI: 2-11%; I2 = 89%), lower than previously reported rates without IONM. Notably, the clinical improvement rate post-surgery was high at 99% (95% CI: 98-100%; I2 = 56%). The analysis also showed lower reoperation rates in surgeries with IONM compared to those without. Interestingly, no mortality was observed in the included studies. This systematic review and meta-analysis indicate that intraoperative neuromonitoring in Chiari I malformation surgery is associated with favorable clinical outcomes, including lower complication and reoperation rates, and high rates of clinical improvement.

Assessment of auditory hypersensitivity in children and adolescents with Autism Spectrum Disorder: integrative review

Introduction: Individuals with Autism Spectrum Disorder may present impairments in communication, behavior, social interaction and changes in sensory processing with atypical responses to information from the senses, such as auditory hypersensitivity. Objective: to describe the methods of evaluating auditory hypersensitivity used in babies, children and/or adolescents with Autism Spectrum Disorder, through an integrative review. Data Synthesis: The study was carried out with the PVO strategy, in the months of October and November 2023, with the search key: “Infant” OR “Child” OR “Adolescent” AND “Autism Spectrum Disorder” AND “Hyperacusis” OR “ Hyperacuses” OR "Hearing” in 11 databases. Results: 7,071 studies were identified, after reading titles and abstracts, 59 were selected, 30 of which were duplicates and 29 were read in full. In the end, 10 articles were included. The majority of studies carried out audiological exams followed by a questionnaire, with the Sensory Profile questionnaire being the most common and the Otoacoustic Emissions, Brainstem Auditory Evoked Potential and Immittance Tests being the most common. The sounds that cause the most discomfort are: sounds of strong intensity in general, such as, vacuum cleaner and hairdryer. The most common emotional reaction was crying and physical reactions, covering the ears and running away. Conclusion: It was noticed that the majority of studies reported in this review demonstrate that for the investigation of auditory hypersensitivity, it can be both questionnaires and hearing exams were used in children and adolescents with auditory hypersensitivity, making it necessary to carry out more studies on the subject to standardize an assessment for auditory hypersensitivity.

Evaluation of otoacoustic emissions and brainstem auditory evoked potential in infants with birth asphyxia

Background: Recent technological evolutions allow for the identification of hearing level (HL) in infants soon after birth. The goal of early hearing detection and intervention is to maximize linguistic and communication skills and literacy development for children who are deaf or hard of hearing. Infants whose HL has been confirmed before 6 months of age must be provided early intervention. Aims and Objectives: The aim of the study was to observe the changes in the otoacoustic emissions (OAE) and brainstem auditory evoked potential (BAEP) in infants with birth asphyxia (BA). Materials and Methods: The present study was a case–control study. A total of 50 cases of infants with BA and 50 normal-term infants were part of the study after obtaining informed consent as per the ICMR guidelines. A through clinical examination and otoscopy examination were done to rule out any conductive hearing loss. Then, OAE and BAEP were recorded to estimate the hearing loss and hearing threshold of infants. Results: BAEP waveform I, III, and V absolute latencies were significantly prolonged among BA infants than normal infants. The interpeak latency (IPL) of the right ear III-V was significantly increased in BA infants. However, III-V and I-V latencies though prolonged in BA infants, they are not statistically significant. No significant interaural difference was noted in absolute and IPLs of both BA and normal infants. No significant relationship existed between the mode of delivery and the degree of hearing loss in both ears. Significant association was observed between the degree of hearing loss and severity of BA (hypoxic-ischemic encephalopathy) in both ears. Conclusion: BAEP recording in BA infants is useful to identify the hearing impairment at the earliest. The implication of this research work will help in early detection of hearing impairment, so that speech and language developmental delay in the child can be prevented.

Effect of the Heaviness of Smoking Index (HSI) and Duration of Smoking on Central Neural Processing Using Brainstem Auditory Evoked Responses (BAERs).

Purpose of study The goal of this research was to find the correlation of nicotine dependence and duration of smoking with the status of central neuronal processing in chronic smokers. Our primary objective was to record brainstem auditory evoked responses (BAERs) in chronic smokers and further find their correlation to the Heaviness of Smoking Index (HSI) scores and years of non-abstained smoking of the subjects. We postulated that smoking leads to myelination abnormalities which in turn causes decreased impulse conduction velocity. Methods After obtaining informed consent, we conducted BAER on 60 male smokers who were further classified into groups based on their HSI scores (low, moderate, and high nicotine dependency) and 20 age-matched, non-smoking males. The obtained data was examined using the two-way ANOVA test and the Kruskal-Wallis test. Pearson's coefficient of correlationand the median (as a measure of central tendency) were calculated. Results We observed a non-significant negative correlation between wave I BAER latency and the degree of nicotine dependence. Wave II showed minimal correlation, whereas a positive correlation was seen in waves III, IV, and V. Interpeak latencies (IPL) I-III and III-V showed a non-significant positive correlation with the HSI score, whereas IPL I-V showed a significant positive correlation with the same. When correlated with the duration of smoking (years), the latencies (msec) of BAER waves I-V showed a pattern of progressively decreasing negative correlation, out of which waves I, II, and III were significantly affected. The IPL (msec) of waves I-III was non-significantly, yet positively, correlated, while the IPL of waves I-V and III-V showed a significant positive correlation to the duration of smoking. Conclusions The degree of nicotine dependence and duration of tobacco smoking progressively affected the latencies of BAER waves at the pontomedullary level of the brainstem. This indicates slower central neuronal processing at this level and an increased central transmission time, the extent of which is directly dependent on the extent of tobacco smoking. This is attributed to the myelination defects caused by direct and indirect effects of the toxic metabolites of tobacco smoke, chronic hypoxia, hypercapnia, and respiratory acidosis.

A phase 2a study investigating the effects of ritlecitinib on brainstem auditory evoked potentials and intraepidermal nerve fiber histology in adults with alopecia areata.

Reversible axonal swelling and brainstem auditory evoked potential (BAEP) changes were observed in standard chronic (9-month) toxicology studies in dogs treated with ritlecitinib, an oral Janus kinase 3/tyrosine kinase expressed in hepatocellular carcinoma family kinase inhibitor, at exposures higher than the approved 50-mg human dose. To evaluate the clinical relevance of the dog toxicity finding, this phase 2a, double-blind study assessed BAEP changes and intraepidermal nerve fiber (IENF) histology in adults with alopecia areata treated with ritlecitinib. Patients were randomized to receive oral ritlecitinib 50 mg once daily (QD) with a 4-week loading dose of 200 mg QD or placebo for 9 months (placebo-controlled phase); they then entered the active-therapy extension and received ritlecitinib 50 mg QD (with a 4-week loading dose of 200 mg in patients switching from placebo). Among the 71 patients, no notable mean differences in change from baseline (CFB) in Waves I-V interwave latency (primary outcome) or Wave V amplitude on BAEP at a stimulus intensity of 80 dB nHL were observed in the ritlecitinib or placebo group at Month 9, with no notable differences in interwave latency or Wave V amplitude between groups. The CFB in mean or median IENF density and in percentage of IENFs with axonal swellings was minimal and similar between groups at Month 9. Ritlecitinib treatment was also not associated with an imbalanced incidence of neurological and audiological adverse events. These results provide evidence that the BAEP and axonal swelling finding in dogs are not clinically relevant in humans.

Brainstem auditory evoked responses in horses with hearing loss and during general anesthesia

The brainstem auditory evoked response (BAER) is a diagnostic approach to examine the hearing system of horses objectively. The aim of this BAER examination was the diagnosis of conductive or sensorineural hearing loss or deafness in horses with external otitis, head trauma, headshaking, tinnitus or skittish horses with eye disease. Brainstem dysfunction is induced by intracranial hypotension. BAER was used in horses with colic surgery which had a low arterial blood pressure during general anesthesia. The endoscopic finding of the guttural pouch was the ipsilateral mild to severe hypertrophy of the tympanostylohyoideum in horses with external otitis or head trauma. The otoscopic examination of standing sedated horses was done before BAER. The cartilagineous and osseous part of the external ear canal in horses with external otitis were obstructed with exsudate and tympanic membranes were not visible. Horses with right sided external otitis: right moderate to severe conductive hearing loss (significantly prolonged latencies of I, III, V and interpeak latencies I-III, I-V, III-V; thresholds of hearing levels 60 to 80 dB right); horses with left sided external otitis: left severe conductive hearing loss (no correct identification of BAER peaks, latencies not measurable, 80 dB); horse with left sided head trauma: severe left sided conductive hearing loss (blood in the left external ear canal, no visible tympanic membrane, no correct identification of BAER peaks, latencies not measurable, 80 dB); horses with head shaking: mild sensorineural hearing loss on both sides (on both sides osseous parts II/III with keratin scales of the junction, visible tympanic membranes, significantly prolonged V, I-III, I-V, 40 dB); moderate to severe skittish horses with chronic eye disease (mostly left sided equine recurrent uveitis): moderate sensorineural hearing loss on both sides (normal otoscopical findings, significantly prolonged latencies and interpeak latencies left; I-V, III-V right, 60 dB, pathological involvement in the auditory pathway of the brainstem between the cochlear nucleus and colliculus caudalis); horse with a tinnitus on both sides: mild sensorineural hearing loss on both sides (normal otoscopical findings, prolonged V, I-III, I-V, III-V, 40 dB, pathology of auditory nerve, cochlear nucleus and above the level of this nucleus); American paint horses: sensorineurale deafness on both sides (normal otoscopical findings, absent BAER peaks, isoelectric lines and 80 dB on both sides). The prolonged latencies of I, III and V including interpeak latencies I-III only left and I-V and III-V on both sides in horses with laparotomy during general anesthesia were associated with low arterial blood pressure (62 mmHg, median). These findings could demonstrate a hypotension in the brainstem too. The BAER could be a technical tool during general anesthesia for normalizing the arterial blood pressure and brainstem function to prevent imbalance of body movements after general anesthesia.

Hearing Assessment of Free-Ranging Owls and Implications for Wildlife Rehabilitation: 31 Cases (2014-2023).

Owls, members of the avian order Strigiformes, are nocturnal birds of prey that are found worldwide except for Antarctica. Traumatized, free-ranging owls are commonly presented to veterinary hospitals and wildlife rehabilitation facilities with the goal of providing medical care and rehabilitation to enable release back into their natural habitat. Minimal guidelines exist for the release of wildlife, and whereas a need for functional vision is described in raptors, assessing and evaluating hearing is usually not mentioned. This can be problematic for nocturnal predators because hearing is the primary sense utilized by owls when hunting and navigating in their dark environment. The brainstem auditory evoked response (BAER) test is a minimally invasive, objective assessment of hearing commonly used in companion animals. To the authors' knowledge, routine or standardized BAER evaluation has not been reported in traumatized, free-ranging owls. In the following retrospective study, 31 free-ranging owls presented to the University of Georgia Veterinary Teaching Hospital for known or suspected trauma or being found in a debilitated state underwent BAER testing to assess for the presence of complete sensorineural hearing loss. Similar to assessment of hearing in companion animals, the BAER test was elicited using a broad click stimulus delivered at 85 dB nHL. In all owls, qualitative assessment and peak latency measurements of the BAER test reflected hearing ability. This study highlights the importance of hearing in nocturnal raptors, how BAER testing can aid in decision making regarding rehabilitation, and provides a foundation for further investigation of hearing loss in traumatized owls. We suggest that veterinarians working with free-ranging owls in a rehabilitation setting should consider BAER testing as part of routine diagnostic testing.

Evaluation of Brainstem Auditory-Evoked Potentials in Infants with Iron Deficiency Anemia

Purpose: To evaluate and compare the brain functions of infants with and without Iron Deficiency anaemia (IDA) electrophysiologically with brainstem auditory potentials (BAEPs). Materials and Methods: BAEP tests were performed on 26 healthy infants and 26 infants with iron deficiency anaemia, aged 6-24 months, who were followed through the Paediatric Haematology Department at SDU Faculty of Medicine. Children were classified as anaemic if their haemoglobin (Hb) level fell below -2 standard deviations for their age. All patients diagnosed with iron deficiency anaemia received 5 mg/kg/day of divalent iron glycine sulphate complex in three doses daily for a duration of 12 weeks, to be taken on an empty stomach. Both group were orally administered Chloral hydrate at a dosage of 50mg/kg prior to the BAEP test to induce sedation. The BAEP was recorded at a sound intensity level of 90 decibels, with a frequency of 10 Hertz, and with click stimuli ranging from 1000 to 2000. The BAEP test was administered to the IDA group before and after treatment, as well as to the control group, with a 3-month interval between tests. Results: 14 (53.8%) of the IDA patients were males, and 16 (61.5%) of the control group were females. Patients with IDA had an average age of 14.4±3.09 months, while the control group patients have an average age of 11.2±4.04 months. Patients with iron deficiency anaemia had lower pre-treatment levels of Hb, Hct, MCV, MCH, MCHC, transferrin saturation percentage, and ferritin compared to the control group, whereas platelet and RDW values were greater (p˂0.001). The study compared the Brainstem Auditory Evoked Potential (BAEP) values of patients with Iron Deficiency Anaemia (IDA) before treatment with those of control patients. The results indicated that the III-V interval, showing nerve conduction time, was significantly prolonged in the pre-treatment BAEPs (p˂0.05). There was no significant difference in interpeak latencies between the control group and patients with iron deficiency anaemia (IDA) following therapy (p˂0.05). Significant differences were found in the I-III, III-V, and I-V interpeak latencies of individuals with iron deficiency anaemia before and after treatment (p

Novel standardized indexes of brainstem auditory evoked potentials for predicting hearing preservation in vestibular schwannomas

Hearing preservation (HP) during vestibular schwannomas (VSs) surgery poses a significant challenge. Although brainstem auditory evoked potentials (BAEPs) on the affected side are commonly employed to monitor cochlear nerve function, their low signal-to-noise ratio (SNR) renders them susceptible to interferences, compromising their reliability. We retrospectively analyzed the data of patients who underwent tumor resection, while binaural brainstem auditory evoked potentials (BAEPs) were simultaneously recorded during surgery. To standardize BAEPs on the affected side, we incorporated the synchronous healthy side as a reference (interval between affected and healthy side ≤ 3 min). A total of 127 patients were enrolled. Comparison of the raw BAEPs data pre- and post-tumor resection revealed that neither V-wave amplitude (Am-V) nor latency (La-V) could serve as reliable predictors of HP simultaneously. However, following standardization, V-wave latency (STIAS-La-V) and amplitude (STIAS-Am-V) emerged as stable predictors of HP. Furthermore, the intraoperative difference in V-wave amplitude (D-Am-V) predicted postoperative HP in patients with preoperative HP and remained predictive after standardization. The utilization of intraoperative synchronous healthy side BAEPs as a reference to eliminate interferences proves to be an effective approach in enhancing the reliability of BAEPs for predicting HP in VSs patients.

Evaluation of audiovestibular functions in patients with posterior circulation cerebrovascular stroke

BackgroundIt has been found that 25% of posterior circulation stroke patients experience vertigo. Sudden hearing loss due to a vascular source is typically caused by infarction in the anterior inferior cerebellar artery territory. However, it is uncommon in the posterior inferior cerebellar artery territory infarction.Aim of the workThe objective of the proposed study is to evaluate the function of the auditory and vestibular system in patients with posterior circulation cerebrovascular stroke.MethodsFifty patients with posterior circulation stroke, diagnosed by MRI at least 3 months after onset, were included. The controls consisted of fifty healthy people. The average age in cases was 58.68 ± 8.60 years, while in controls, it was 55.44 ± 11.72. The Health Stroke Scale (NIHSS) was used to conduct clinical assessments. All study groups were investigated using pure tone audiometry, auditory brain stem-evoked potential (ABR), videonystagmography (VNG), and vestibular-evoked myogenic potential (VEMP).ResultsMRI findings revealed that pontine infarction was the most frequent lesion in 36 (72%) patients. The latencies of ABR waves I, III, V, 1–III, I–V, and III–V were all considerably longer in cases than controls. Cervical VEMP P1 latency was considerably delayed in cases compared to controls, as the amplitude was lower. VNG data found abnormalities in all test parameters, indicating central disease.ConclusionPosterior circulation stroke causes acute sensorineural hearing loss with varying degrees. Videonystagmography is an accurate assessment of oculomotor function that can be combined with vestibular-evoked myogenic potential to objectively assess posterior circulation stroke patients.

Genetic and phenotypic analysis of 225 Chinese children with developmental delay and/or intellectual disability using whole-exome sequencing

Developmental delay (DD), or intellectual disability (ID) is a very large group of early onset disorders that affects 1–2% of children worldwide, which have diverse genetic causes that should be identified. Genetic studies can elucidate the pathogenesis underlying DD/ID. In this study, whole-exome sequencing (WES) was performed on 225 Chinese DD/ID children (208 cases were sequenced as proband-parent trio) who were classified into seven phenotype subgroups. The phenotype and genomic data of patients with DD/ID were further retrospectively analyzed. There were 96/225 (42.67%; 95% confidence interval [CI] 36.15–49.18%) patients were found to have causative single nucleotide variants (SNVs) and small insertions/deletions (Indels) associated with DD/ID based on WES data. The diagnostic yields among the seven subgroups ranged from 31.25 to 71.43%. Three specific clinical features, hearing loss, visual loss, and facial dysmorphism, can significantly increase the diagnostic yield of WES in patients with DD/ID (P = 0.005, P = 0.005, and P = 0.039, respectively). Of note, hearing loss (odds ratio [OR] = 1.86%; 95% CI = 1.00-3.46, P = 0.046) or abnormal brainstem auditory evoked potential (BAEP) (OR = 1.91, 95% CI = 1.02–3.50, P = 0.042) was independently associated with causative genetic variants in DD/ID children. Our findings enrich the variation spectrums of SNVs/Indels associated with DD/ID, highlight the value genetic testing for DD/ID children, stress the importance of BAEP screen in DD/ID children, and help to facilitate early diagnose, clinical management and reproductive decisions, improve therapeutic response to medical treatment.

Evaluation of Hearing Loss in Patients with Essential Tremor

ABSTRACT Background: Essential tremor (ET) is a common chronic progressive disease, characterized by postural and action tremor. Abnormalities within the cerebello-thalamocortical pathways are thought to be involved in ET. In some studies, it was reported that there is an association between ET and hearing loss. Objective: In this study, our goal is to examine the electrophysiological changes of the structures forming the auditory pathway in ET cases, and the relationship of these changes with clinical findings and understand if the pathology underlying hearing loss in ET is cochlear or retrocochlear. Materials and Methods: One hundred sequential ET patients who had referred to Mersin University Faculty of Medicine Neurology Department, and 100 healthy individuals that are equivalent in terms of age and gender were conducted to investigate this association. Detailed medical history, neurologic examination, audiologic examination, pure-tone audiometry (PTA), tympanometry, and auditory brainstem response (ABR) analyses also known as brainstem auditory-evoked potentials were applied to all patients and controls. Results: The mean age of patients with ET was 56.38 ± 16.73, and the mean age of individuals in the control group was 56.47 ± 16.86. Nineteen of the patients with ET, and two healthy individuals from the control group had hearing problems (P < 0.001). In this study, there were no significant differences found in audiometric and ABR examinations in terms of hearing loss between the ET group and control group. However, in audiometric and ABR analyses, an increase in hearing loss was found to be correlated with an increase in tremor severity. In PTA test, hearing loss was higher in those with high-intensity tremor severity than in the group with mild tremor severity. This was statistically significant. P (KW) <0.05 Pposthoc < 0.05. In ABR analysis, it was found that there was a statistically significant difference with the increase of tremor severity at the dominant hand with: wave V latencies of the right and left ear; I-V interpeak latencies of the right ear, and III-V interpeak latencies of the right ear. The difference was between mild and moderate tremor groups. Conclusion: This study shows that there could be an impairment in inhibiting the functional transmission in the brainstem of patients with ET.

The effects of upper cervical spine manual therapy on central sensitization and brainstem auditory evoked potentials in subjects with migraine and neck pain

BackgroundMigraine is an important disease due to its impact on global health. Due to association of neck pain with migraine, manual therapy (MT) often used in management. The aim of this study was to evaluate the effects of upper cervical spine MT on specific mechanisms including central sensitization (CS) and brainstem auditory evoked potentials (BAEPs) in subjects with migraine and neck pain. Methods30 subjects with migraine and neck pain (30 female, mean age 43.10 ± 8.13) were randomly assigned to a medication plus MT (MedMT) group, a medication plus sham manual therapy (sham MT) group, and a medication alone (Med) group. CS was evaluated using the Central Sensitization Inventory (CSI) and BAEP determined electrophysiologically in all subjects pre and post intervention. Subjects in MedMT and sham MT groups received either 4 sessions of MT or sham MT. All subjects received medication. ResultsSubjects in MedMT group had a significant reduction in CSI score (P < 0.05) compare to the other 2 groups. For BAEPs, MedMT and sham MT groups had significantly decreased wave V latency on the right side (P < 0.05) compared to Med group. DiscussionManual therapy plus medication may have beneficial effects in people with migraine and neck pain by normalizing central sensitization levels. Additionally, upper cervical manual therapy or sham manual therapy have demonstrable neurophysiological effects reflected by changes in the auditory transmission pathways in the brainstem. Further research is required to investigate the mechanisms of action of MT in migraine.

From periphery to center, untold story of pure neuritic leprosy: an electrophysiological study.

Pure neuritic leprosy (PNL) is uncommon form of leprosy involving peripheral nerves. Some isolated case reports have shown imaging changes in the central nervous system (CNS) and also impairment in visual evoked potential (VEP), somatosensory evoked potential (SSEP) and brain stem auditory-evoked potentials (BAEPs) parameters in PNL, but there is lack of large study. This prospective observational study evaluates impairment in these central conduction studies among PNL patients. We screened patients with leprosy presenting with features of neuropathy and/or thickened nerves. Patients with bacilli-positive nerve biopsies were included in the study and subjected to routine tests along with nerve conduction study (NCS), VEP, tibial SSEP and BAEPs. Parameters of these studies were analyzed based on data from previous studies. Of 76 patients screened for PNL 49 had positive findings in biopsy. Most of patients were male and mean age group was 46.35 ± 15.35years. Mononeuritis multiplex was most common NCS pattern in 46.93% (23/49) patients. We found abnormal VEP in 13 out of 35 patients (37.14%). Similarly abnormal SSEP and BAEPs among 42.85% and 40% patients respectively. This study shows that in PNL significant number of patients have subclinical CNS involvement. Exact pathophysiology of CNS involvement is not known till now but study of VEP, SSEP and BAEPs parameter may help in early diagnosis of PNL.

Multimodal evoked potentials are useful for the diagnosis of pediatric acute disseminated encephalomyelitis.

The application of evoked potentials (EPs) to the diagnosis of acute disseminated encephalomyelitis (ADEM ) has not been investigated in detail. The aim of this study, therefore, was to analyze the value of multimodal EPs in the early diagnosis of pediatric ADEM. This was a retrospective study in which we enrolled pediatric ADEM patients and controls (Cs) from neurology units between 2017 and 2021. We measured indices in patients using brainstem auditory evoked potentials (BAEPs), visual evoked potentials (VEPs) and somatosensory evoked potentials (SEPs), and then we analyzed their early diagnostic value in ADEM patients. The mean age of the ADEM group was 6.15 ± 3.28 years (range,1-12 years) and the male/female ratio was 2.1:1 The mean age of the Cs was 5.97 ± 3.40 years (range,1-12 years) and the male/female ratio was 1.3:1. As we used magnetic resonance imaging (MRI) as the diagnostic criterion, the sensitivity, specificity, and accuracy (κ was 0.88) of multimodal EPs were highly consistent with those of MRI; and the validity could be ranked in the following order with respect to the diagnosis of ADEM: multimodal Eps > single SEP > single VEP > single BAEP. Of 34 patients with ADEM, abnormalities in multimodal EPs were 94.12%, while abnormalities in single VEPs, BAEPs and SEPs were 70.59%,64.71%and 85.3%, respectively. We noted significant differences between single VEP/BAEPs and multimodal EPs (χ2 = 6.476/8.995,P = 0.011/0.003). The combined application of multimodal EPs was superior to BAEPs, VEPs, or SEPs alone in detecting the existence of central nerve demyelination, and we hypothesize that these modalities will be applicable in the early diagnosis of ADEM.

Brainstem auditory evoked responses in newly diagnosed untreated hypothyroid females

Background: Hypothyroidism stands as a prevalent endocrine disorder, affecting females more than males. Among the array of otolaryngological manifestations linked with thyroid dysfunctions, sensorineural hearing loss emerges as the most frequently encountered issue. Evoked potentials serve as valuable tools extensively utilized in studying brain disturbances. Among these evoked potentials, Brainstem Auditory Evoked Response (BAER) stands out as one of the methods employed for assessing the pathology within the brainstem auditory pathway. Aims and Objectives: The aim of the study is to evaluate the auditory sensory process in the brainstem using BAERs in newly diagnosed untreated hypothyroid individuals. Materials and Methods: Forty newly diagnosed untreated hypothyroid females of 20–50 years were taken as cases and forty age-matched females were considered controls. The hypothyroidism was diagnosed by estimating the serum levels of free T3 (fT3), free T4 (fT4), and thyroid-stimulating hormone. After getting informed written consent, the absolute latencies and interpeak latencies of BAER were recorded using NeuroPerfect EMG 2000 system with installed BAER in the research laboratory, Department of Physiology, Coimbatore Medical College, Coimbatore, and the data were analyzed by student unpaired t-test. Results: The absolute latencies I, III, V and interpeak latencies I- III, III- V, I – V were significantly prolonged in newly diagnosed untreated hypothyroid females (P &lt; 0.0001) and also there was a direct correlation between thyroid profile changes and the BAER latencies. Conclusion: The results of the present study suggest that hypothyroidism impacts the auditory pathway diffusely and early identification of auditory pathway involvement in thyroid hormone deficiency can be achieved using BAER. Prolonged BAER latencies observed in newly diagnosed untreated hypothyroid females are attributed to defective myelination of neural pathways and diminished cerebral metabolism. Hence, integrating BAER recordings into screening protocols could enhance the accuracy and early assessment of neurological involvement in hypothyroid females.

Brainstem auditory evoked potential variability in unmedicated schizophrenic patients

Background: Schizophrenia (SCZ) is one of the most incapacitating and financially disastrous medical conditions and ranks among the most severe and burdensome diseases in the world due to the onset, progression, and frequency of disability. Few researches have been reported that SCZ is linked to a number of neurophysiological abnormalities, including changes in brainstem auditory evoked potentials (BAEPs). Aims and Objectives: The current study aimedto measure brainstem function using BAEPs in patients with SCZ and compare their findings with healthy controls. Materials and Methods: A cross-sectional case–control study was conducted on 51 schizophrenic drug-naive patients selected from the outpatient department of psychiatry, fulfilling the diagnostic criteria of DSM-IV, aged 18-28 years, male and female, with a matching control group of 50 subjects recruited from patients’ relatives. For assessing the severity of SCZ, the positive and negative syndrome scale was utilized. The BAEPs were recorded using a brainstem-evoked response audiometry (BERA) device (NeuroStim-NS 2). Data were analyzed using Independent t-test and Mann–Whitney test based on normality. P-value was considered significant at P &lt; 0.05, P &lt; 0.01 level. Results: A significant difference was observed in patients and control group BAEPs. The absolute latency of waves I and III in the right ear, waves I and V, IPL I-III in the left ear was shown to be significantly different. The results demonstrate that the patient group’s mean latency was higher than the controls. Conclusion: Based on findings, it was concluded that abnormal BAEPs in schizophrenic patients might be attributed to their primary symptom of discontinuity in perceptual and other cerebral functions and slower transmission in the lower brainstem auditory pathway and decreased activity at the brainstem level.