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.

Assessing the Brainstem Auditory Evoked Potentials in Subjects with Family History of Hypertension.

Background: Hypertension (HTN) has a genetic predisposition and it also impairs microcirculation, thereby, affecting the well vascularized structures like the brainstem and causing changes in Brainstem Auditory Evoked Potentials (BAEPs). Purpose: To find out the usefulness of BAEPs as a screening tool in apparently healthy individuals with a family history of HTN. Methods: One hundred and ten volunteers, aged 17 to 23 years, were enrolled in the study as participants with proper consent. After excluding the subjects with existing diseases or co-morbidities (e.g. diabetes, HTN, schizophrenia, neuropathy, etc.), those on ototoxic or neurotoxic drugs, a preliminary physical examination was performed, following which BAEPs were recorded with a proper device. Statistical analysis is done with SPSS 2016 software using the chi-square test. Results: A consistent distortion in the inter-peak latency of III-V waves is noted when a family history of HTN is present in either parent or maternal grandparents. Other statistically significant findings are present in V/I% (HTN in mother), wave I (HTN in paternal grandfather), wave III (HTN in maternal grandfather), and inter-peak latency I-V (HTN in maternal grandmother). Conclusion: BAEP may be used as a screening tool in individuals with a family history of HTN with supportive evidence from further studies in the near future.

A Comprehensive Review and Practical Guide of the Applications of Evoked Potentials in Neuroprognostication After Cardiac Arrest.

Cardiorespiratory arrest is a very common cause of morbidity and mortality nowadays, and many therapeutic strategies, such as induced coma or targeted temperature management, are used to reduce patient sequelae. However, these procedures can alter a patient's neurological status, making it difficult to obtain useful clinical information for the reliable estimation of neurological prognosis. Therefore, complementary investigations are conducted in the early stages after a cardiac arrest to clarify functional prognosis in comatose cardiac arrest survivors in the first few hours or days. Current practice relies on a multimodal approach, which shows its greatest potential in predicting poor functional prognosis, whereas the data and tools to identify patients with good functional prognosis remain relatively limited in comparison. Therefore, there is considerable interest in investigating alternative biological parameters and advanced imaging technique studies. Among these, somatosensory evoked potentials (SSEPs) remain one of the simplest and most reliable tools. In this article, we discuss the technical principles, advantages, limitations, and prognostic implications of SSEPs in detail. We will also review other types of evoked potentials that can provide useful information but are less commonly used in clinical practice (e.g., visual evoked potentials; short-, medium-, and long-latency auditory evoked potentials; and event-related evoked potentials, such as mismatch negativity or P300).

Sensorineural deafness in purebred white Devon Rex cats.

BACKGROUND: Data regarding congenital sensorineural deafness (CSD) in client-owned, white Devon Rex cats is limited because most of the information on this disease comes from experiments on mixed-breed cats. OBJECTIVES: Provide data on the occurrence of CSD in a population of client-owned purebred white Devon Rex cats. ANIMALS: Forty client-owned, purebred, white Devon Rex cats examined at 2 different facilities. Median age of the examined cats was 19 weeks. METHODS: Hearing status was defined by use of brainstem auditory evoked responses. RESULTS: The occurrence of sensorineural deafness in the studied population of Devon Rex cats was estimated at 10%. Unilateral and bilateral deafness occurred equally often, with 2 individuals having each (ie, 5.0%). No association between the occurrence of CSD and sex could be found, χ2 (1, n = 40) = 0.001 (P > .99). No association between blue irises and deafness was noted in the studied population, χ2 (1, n = 40) < 0.01 (P > .99). CONCLUSIONS: The occurrence of CSD in a population of client-owned, white Devon Rex cats was found to be lower compared with data obtained in previously conducted studies of deafness in purebred cats. In the studied population of Devon Rex cats, no association between blue irises and CSD was found.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

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

Background: 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. Methods: 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. Results: 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. Conclusion: 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. Clinical trial registration: http://www.chictr.org.cn, Identifier ChiCTR2200066629.

Characterisation of Patients with SH3TC2 Associated Neuropathy in an Indian Cohort.

Background: SH3TC2 variations lead to demyelinating recessive Charcot-Marie-Tooth (CMT) disease, which is commonly associated with early-onset scoliosis and cranial neuropathy. Data from Indian ethnicity is limited. Objective: We aim to report the characteristics of patients with SH3TC2-associated neuropathy from an Indian cohort. Patients and Methods: Data of five unrelated subjects with SH3TC2 variations were analyzed. Results: Clinical features included female predominance (n = 4), early-onset neuropathy (n = 2), pes cavus and hammer toes (n = 4), kyphoscoliosis (n = 1), impaired vision and hearing (n = 1), facial muscle weakness (n = 1), impaired kinaesthetic sense (n = 3), tremor (n = 2), and ataxia (n = 1). Four patients had the "CMT" phenotype, while one patient had Roussy-Levy syndrome. All had demyelinating electrophysiology with conduction velocities being "very slow" in one, "slow" in one, "mildly slow" in two, and "intermediate" in one patient. Brain stem auditory evoked potentials were universally abnormal though only one patient had symptomatic deafness. Seven variants were identified in SH3TC2 [homozygous = 3 (c.1412del, c.69del, c.3152G>A), heterozygous = 4 (c.1105C>T, c.3511C>T, c.2028G>C, c.254A>T)]. Except for c.3511C>T variant, the rest were novel. Three patients had additional variations in genes having pathobiological relevance in other CMTs or amyotrophic lateral sclerosis. Conclusion: We provide data on a cohort of patients of Indian origin with SH3TC2 variations and highlight differences from other cohorts. Though the majority were not symptomatic for hearing impairment, evoked potentials disclosed abnormalities in all. Further studies are required to establish the functional consequences of novel variants and their interacting molecular partners identified in the present study to strengthen their association with the phenotype.

The Role of Neurophysiology in Managing Patients with Chiari Malformations.

Chiari malformation type 1 (CM1) includes various congenital anomalies that share ectopia of the cerebellar tonsils lower than the foramen magnum, in some cases associated with syringomyelia or hydrocephalus. CM1 can cause dysfunction of the brainstem, spinal cord, and cranial nerves. This functional alteration of the nervous system can be detected by various modalities of neurophysiological tests, such as brainstem auditory evoked potentials, somatosensory evoked potentials, motor evoked potentials, electromyography and nerve conduction studies of the cranial nerves and spinal roots, as well as brainstem reflexes. The main goal of this study is to review the findings of multimodal neurophysiological examinations in published studies of patients with CM1 and their indication in the diagnosis, treatment, and follow-up of these patients, as well as their utility in intraoperative monitoring.

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.

Limiar Diferencial de mascaramento e potencial evocado auditivo de tronco encefálico em adultos normo-ouvintes com zumbido / Masking Level Difference and Auditory Brainstem ResponseIn Normal Hearing Adults With Tinnitus / Umbral de enmascaramiento diferencial y potencial evocado auditivo del tronco encefálico en adultos con audición normal y tinnitus

Introdução: O zumbido é uma ilusão auditiva consciente, uma sensação sonora não relacionada com uma fonte externa de estimulação. Objetivos: Caracterizar a Acufenometria, Limiar Diferencial de Mascaramento, o questionário de qualidade de vida Inventário de Desvantagem do Zumbido e Potencial Auditivo de Tronco Encefálico em adultos normo-ouvintes com zumbido, com a finalidade de comparar seus achados. Método: Vinte indivíduos do sexo feminino e masculino, entre 20 e 60 anos de idade, normo-ouvintes com queixa de zumbido, foram submetidos ao Acufenometria, Limiar Diferencial de Mascaramento, Inventário de Desvantagem do Zumbido e Potencial Evocado Auditivo de Tronco Encefálico. Resultados: AAcufenometriarevelou que o pitch médio foi de 4,3 KHz à orelha direita e 4,6 KHz à orelha esquerda. O loudness médio foi de 21,7 dBNS à orelha direita e 23,5 dBNS à orelha esquerda. O Limiar Diferencial de Mascaramento médio mostrou-se alterado. O Inventário de Desvantagem do Zumbido médio correspondeu à classificação de grau leve. O Potencial Evocado Auditivo de Tronco Encefálico apresentou parâmetros dentro da normalidade bilateralmente. Conclusão: Constatou-se que adultos normo-ouvintes com queixa de zumbido apresentam zumbido de pitch agudo bilateral com discreto impacto na qualidade de vida, condução adequada das vias auditivas até o tronco encefálico e comprometimento na identificação de sons na presença de ruído, demonstrando que o zumbido pode ter repercussões nas habilidades auditivas centrais. (AU)

Introduction: Tinnitus is a conscious auditory illusion, a sound perception unrelated to any external stimulus source. Objectives: To characterize the Acuphenometry, Masking Level Difference, the quality of life questionnaire Tinnitus Handicap Inventory and Auditory Brainstem Response in normal hearing adults with tinnitus, with the purpose of comparing the findings. Method: Twenty female and male individuals, between 20 and 60 years of age, normal hearing with complaints of tinnitus, underwent Acuphenometry, Masking Level Difference, Tinnitus Handicap Inventory and Auditory Brainstem Response. Results: The Acuphenometry showed the average pitch was 4.3 KHz to the right ear and 4.6 KHz to the left ear. The average loudness was 21.7 dBSL to the right ear and 23.5 dBs to the left ear. The average Masking Level Difference was altered. The average Tinnitus Handicap Inventory corresponded to the classification of mild grade. Auditory Brainstem Response showed parameters within normal range bilaterally. Conclusion: It was found that normal hearing adults with tinnitus complaints have bilateral acute pitch tinnitus with a slight impact on quality of life, appropriate conduction of auditory pathways to the brainstem and impaired identification of sounds in the presence of noise, demonstrating that tinnitus can have repercussions on central auditory skills. (AU)

Introducción: El tinnitus es una ilusión auditiva consciente, una sensación de sonido no relacionada con una fuente externa de estimulación. Objetivos: Caracterizar la coincidencia de tono y volumen, el umbral de enmascaramiento diferencial, el inventario de minusvalía para acúfenos y el potencial auditivo del tronco encefálico en adultos normoyentes con acúfenos, con el fin de comparar sus hallazgos. Método:Veinte sujetos masculinos y femeninos, con edades entre 20 y 60 años, audición normal con tinnitus, fueron sometidos a acúfenos, Umbral de Enmascaramiento Diferencial, Inventario de Desventajas de Tinnitus y Potenciales Evocados Auditivos del Tronco Encefalico. Resultados: La combinación de tono y volumen reveló que el tono promedio era de 4,3 KHz en el oído derecho y de 4,6 KHz en el oído izquierdo. Mientras que el volumen medio fue de 21,7 dBNS para el oído derecho y de 23,5 dBNS para el oído izquierdo. Se modificó el umbral diferencial de enmascaramiento promedio. El Inventario de Desventajas de Tinnitus promedio correspondió a la clasificación de grado leve. El Potenciales Evocados Auditivos del Tronco Encefalico presentó parámetros dentro del rango normal bilateralmente. Conclusión:Se encontró que los adultos normooyentes con quejas de tinnitus presentan tinnitus de tono alto bilateral con leve impacto en la calidad de vida, conducción adecuada de las vías auditivas al tronco encefálico y deterioro en la identificación de sonidos en presencia de ruido, demostrando que Tinnitus puede tener repercusiones en las habilidades auditivas centrales. (AU)

Potenciais evocados auditivos de tronco encefálico em indivíduos com doença de Parkinson: revisão de literatura / Brainstem auditory evoked potentials in individuals with Parkinson's disease: literature review

Objetivo: investigar a integridade da via auditiva por meio do Potencial Evocado Auditivo de Tronco Encefálico (PEATE) em indivíduos com Doença de Parkinson (DP) por meio de uma revisão integrativa da literatura. Métodos: foram utilizadas as bases de dados Embase, Google acadêmico, Scielo, bem como o portal eletrônico completo da Biblioteca Virtual da Saúde, com os seguintes descritores: DP (Parkinson Disease ou Parkinsonian Disorders) e PEATE (Evoked Potentials, Auditory, Brain Stem ou Evoked Potentials, Auditory). Foram selecionados artigos nacionais e internacionais, sem limitação de ano ou idioma. Os estudos foram descritos e analisados qualitativamente e quantitativamente quanto à latência absoluta e à amplitude das ondas I, III e V, e quanto aos interpicos I-III, III-V e I-V. Resultados: após exclusão dos títulos repetidos, 420 artigos foram encontrados, sendo que 17 atenderam aos critérios de inclusão. Nos resultados do PEATE, estudos descreveram o aumento da latência de todas as ondas, principalmente das ondas III e V e, também, aumento dos interpicos I-V e III-V. Conclusão: indivíduos com DP apresentam neurodegeneração das vias auditivas centrais com diminuição na velocidade de transmissão neural do estímulo acústico.

Purpose: investigate the integrity of the auditory pathway through the Brainstem Auditory Evoked Potential (BAEP) in individuals with Parkinson's Disease (PD) through an integrative literature review. Methods: Embase, Academic Google, Scielo databases were used, as well as the complete electronic portal of the Virtual Health Library, with the following descriptors: PD (Parkinson Disease or Parkinsonian Disorders) and BAEP (Evoked Potentials, Auditory, Brain Stem or Evoked Potentials, Auditory). National and international articles were selected, without limitation of year or language. The studies were described and analyzed qualitatively and quantitatively regarding the absolute latency and amplitude of waves I, III and V, and regarding the interpeaks I-III, III-V and I-V. Results: After excluding repeated titles, 420 articles were found, however only 17 met the inclusion criteria. In the ABR results, studies described the increase in latency of all waves, especially waves III and V, and also an increase in interpeaks I-V and III-V. Conclusion: individuals with PD present neurodegeneration of the central auditory pathways with a decrease in the neural transmission speed of the acoustic stimulus.

The effect of increase in blood glucose level on hearing loss

Abstract Objective: Previous studies have shown that hearing function is also vulnerable to the effects of diabetes mellitus which can be shown by brainstem auditory evoked potential and distortion product otoacoustic emission recordings. This study aimed to investigate the changes of brainstem auditory evoked potential and distortion product otoacoustic emission in hyperglycemia and whether there is a relationship between reactive oxygen substances production and hearing deterioration in the rat model. Methods: 25 streptozotocin induced diabetic rats were divided into three groups: control, high blood glucose, and diabetes mellitus. Brainstem auditory evoked potential and distortion product otoacoustic emission were recorded, and thiobarbituric acid reactive substances levels were measured in the brainstem tissue. Results: At 8 kHz, the latencies of I, II, III, IV, and V brainstem auditory evoked potential waves in high blood glucose and diabetes mellitus groups were elongated, at 16 kHz, only these wave latencies of the diabetes mellitus group were prolonged compared with the control group. A significant decrease was also found in distortion product otoacoustic emission amplitudes at 4, 6, 8, and 10 kHz in the high blood glucose and diabetes mellitus groups compared to the control group. There was a significant increase in thiobarbituric acid reactive substances values due to the increase in blood glucose levels in the high blood glucose and diabetes mellitus groups compared to the control group. Conclusion: These results suggested that high blood glucose levels may cause hearing impairment not only in the diabetic state but also in the period of hyperglycemia before the onset of manifest diabetes mellitus and reactive oxygen substances may play an important role in the pathophysiology of diabetes mellitus. We suggest that regulating high glucose levels even before the onset of manifest diabetes mellitus may prevent hazardous effects on hearing function. Level of evidence: Level 3.

Evaluation of the prevalence of congenital sensorineural deafness in a population of 72 client-owned purebred white cats examined from 2007 to 2021.

BACKGROUND: Data on sensorineural deafness (CSD) in purebred white client-owned cats is limited as most of the information on this disease entity is assured from mixed-breed experimental colonies. It is known that cats with blue irises are more predisposed to CSD having been described as a condition in which many structures in the inner ear are damaged resulting in hearing loss. Cats with CSD are born deaf or lose their hearing irreversibly within the first 4-5 weeks of life. It is important to diagnose cats with this hereditary condition in order to eliminate affected individuals from breeding. The objectives of this study were to ensure data on prevalence of CSD in a population of 72 client-owned purebred white cats in Poland according to the color of the irises and to determine if there are any predispositions with regard to CSD among different breeds of cats in which the dominant W gene is present. RESULTS: Conducted study included 72 purebred white cats from six different breeds. The prevalence of CSD in the conducted study was 16.7%, CI95 [8.9%; 23.3%]. Unilateral deafness (11.1%, CI95 [4.9%; 20.7%]) was more common than bilateral CSD (5.6%, CI95 [1.5%; 13.6%]). The studies did not show any association between sex and CSD, p = .46. No association between the blue color of irises and deafness in the studied population could be found, p = .91. When compared to the rest of the examined population, no association was found between CSD and a particular breed. CONCLUSIONS: Overall prevalence of CSD regarding the examined population of purebred client-owned cats was reported as lower when compared to previous studies concerning purebred cats. Cats with blue irises are more likely to be deaf in accordance to the current state of knowledge, however in the conducted study, no significant association between the presence of blue irises and deafness in white purebred cats could be identified. In order to eliminate CSD from the population, it is necessary to conduct examinations and diagnose CSD in white cats with blue irises as well as with irises of color other than blue. Association between particular breed and CSD wasn't identified.

The effect of increase in blood glucose level on hearing loss.

OBJECTIVE: Previous studies have shown that hearing function is also vulnerable to the effects of diabetes mellitus which can be shown by brainstem auditory evoked potential and distortion product otoacoustic emission recordings. This study aimed to investigate the changes of brainstem auditory evoked potential and distortion product otoacoustic emission in hyperglycemia and whether there is a relationship between reactive oxygen substances production and hearing deterioration in the rat model. METHODS: 25 streptozotocin induced diabetic rats were divided into three groups: control, high blood glucose, and diabetes mellitus. Brainstem auditory evoked potential and distortion product otoacoustic emission were recorded, and thiobarbituric acid reactive substances levels were measured in the brainstem tissue. RESULTS: At 8 kHz, the latencies of I, II, III, IV, and V brainstem auditory evoked potential waves in high blood glucose and diabetes mellitus groups were elongated, at 16 kHz, only these wave latencies of the diabetes mellitus group were prolonged compared with the control group. A significant decrease was also found in distortion product otoacoustic emission amplitudes at 4, 6, 8, and 10 kHz in the high blood glucose and diabetes mellitus groups compared to the control group. There was a significant increase in thiobarbituric acid reactive substances values due to the increase in blood glucose levels in the high blood glucose and diabetes mellitus groups compared to the control group. CONCLUSION: These results suggested that high blood glucose levels may cause hearing impairment not only in the diabetic state but also in the period of hyperglycemia before the onset of manifest diabetes mellitus and reactive oxygen substances may play an important role in the pathophysiology of diabetes mellitus. We suggest that regulating high glucose levels even before the onset of manifest diabetes mellitus may prevent hazardous effects on hearing function. LEVEL OF EVIDENCE: Level 3.

Intraoperative evoked potential techniques.

There are many recent advances in intraoperative evoked potential techniques for mapping and monitoring neural function during surgery. In particular, somatosensory evoked potential optimization speeds surgical feedback, motor evoked potentials provide selective motor system information, and new visual evoked potential methods promise reliable visual system monitoring. This chapter reviews these advances and provides a comprehensive background for understanding their context and importance.

Utility of intraoperative neuromonitoring for decompression of Chiari type I malformation in 93 adult patients.

OBJECTIVE: There is currently a lack of consensus on the utility of intraoperative neuromonitoring (IONM) for decompression of Chiari type I malformation (CM-I). Commonly used monitoring modalities include somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), and brainstem auditory evoked potentials (BAEPs). The purpose of this study was to evaluate the utility of IONM in preventing neurological injury for CM-I decompression. METHODS: The authors conducted a retrospective study of a population of adult patients (ages 17-76 years) diagnosed with CM-I between 2013 and 2021. IONM modalities included SSEPs, MEPs, and/or BAEPs. Prepositioning baseline signals and operative alerts of significant signal attenuation were recorded. RESULTS: Ninety-three patients (average age 38.4 ± 14.6 years) underwent a suboccipital craniectomy for CM-I decompression. Eighty-two (88.2%) of 93 patients underwent C1 laminectomy, 8 (8.6%) underwent C1 and C2 laminectomy, and 4 (4.3%) underwent suboccipital craniectomy with concomitant cervical decompression and fusion in the setting of degenerative cervical spondylosis. Radiographically, the average cerebellar tonsillar ectopia/descent was 1.1 ± 0.5 cm and 53 (57.0%) of 93 patients presented with a syrinx. The average number of vertebral levels traversed by the syrinx was 5.3 ± 3.5, and the average maximum width of the syrinx was 5.8 ± 3.3 mm. There was one instance (1/93, 1.1%) of an MEP alert, which resolved spontaneously after 10 minutes in a patient who had concomitant stenosis due to pannus formation at C1-2. No patient developed a permanent neurological complication. CONCLUSIONS: There were no permanent complications related to intraoperative neurological injury. Transient fluctuations in IONM signals can be detected without clinical significance. The authors suggest that CM-I suboccipital decompression surgery may be performed safely without IONM. The use of IONM in patients with additional occipitocervical pathology should be left as an option to the performing surgeon on a case-by-case basis.

Usefulness of intraoperative monitoring in microvascular decompression for hemifacial spasm: a systematic review and meta-analysis.

OBJECTIVE: To review the diagnostic accuracy and possible added value of Brainstem Auditory Evoked Potentials (BAEP) monitoring and Lateral Spread Response (LSR) monitoring in microvascular decompression surgery for hemifacial spasms. METHODS: For this systematic review we followed the PRISMA guidelines. We searched different databases and bibliographies of articles. We included studies on BAEP and LSR monitoring that reported data on hearing outcome or efficacy. Selected studies were assessed for bias using the MINORS tool. RESULTS: 64 articles were selected for qualitative synthesis, 42 met inclusion criteria for meta-analysis. The overall incidence of hearing loss was 3.4%. For BAEP monitoring AUC and pooled OR with 95% confidence interval were 0.911 (0.753-0.933) and 7.99 (3.85-16.60) respectively. Short-term data on LSR monitoring showed an overall spasm relief rate of 89% with pooled OR, sensitivity and specificity with a 95% confidence interval of 8.80 (4.82-16.08), 0.911 (0.863-0.943) and 0.451 (0.342-0.564) respectively. Long-term data on LSR monitoring showed an overall spasm relief rate of 95% with pooled OR, sensitivity and specificity with a 95% confidence interval of 4.06 (2.15-7.64), 0.871 (0.817-0.911) and 0.39 (0.294-0.495) respectively. CONCLUSION: The alarm criteria, a wave V latency prolongation of 1ms or a wave V amplitude decrement of 50%, proposed by the 'American Clinical Neurophysiology Society' are a sensitive predictor for postoperative hearing loss. Other BAEP wave changes, for example, complete loss of wave V, are more specific but correspond to irreversible damage and are therefore not useful as warning criteria. LSR monitoring has high diagnostic accuracy at short-term follow-up. At long-term follow-up, diagnostic accuracy decreases because most patients get spasm relief regardless of their LSR status. LSR persistence after surgery has a good long-term outcome, as long as an extensive exploration of the facial nerve has been performed.

Audiological profile of individuals with Cornelia de Lange syndrome: an integrative review / Perfil audiológico de indivíduos com síndrome de Cornelia de Lange: revisão integrativa da literatura

ABSTRACT Purpose: to describe the audiological profile of patients with Cornelia de Lange syndrome (CdLS) in an integrative review of the literature. Methods: after developing the research question, articles were searched in six databases (EMBASE, ISI of Knowledge, LILACS, MEDLINE/PubMed, SciELO, and Scopus) and in sources of information (Google Scholar, OpenGrey, and ProQuest), with the following descriptors: audiology, hearing loss, deafness, hearing disorders, and Cornelia de Lange syndrome. This review was registered in Prospero under number CRD42020191481. National and international studies were considered for analysis, using the PECO acronym. The risk of bias in the studies was analyzed with Joanna Briggs Institute protocols. Then, the studies were described and analyzed. Results: of the 1,080 articles found, 12 met the inclusion criteria. Audiological results showed that individuals with CdLS can have hearing loss - conductive hearing losses were the most frequent impairments, corresponding to 49.20% of individuals with CdLS assessed, followed by sensorineural hearing losses (13.49%). The degrees of hearing loss ranged from mild to profound. Conclusion: individuals presented with CdLS often have hearing loss, mainly due to middle ear changes, with degrees ranging from mild to profound.

RESUMO Objetivo: descrever o perfil audiológico de pacientes com Síndrome de Cornelia de Lange (SCdL), por meio de uma revisão integrativa da literatura. Métodos: após formulação da pergunta, realizou-se uma busca em seis bases de dados (Embase, ISI of Knowledge, Lilacs, Medline/PubMed, Scielo e Scopus), e fontes de informação (Google Acadêmico, OpenGrey e Proquest), com os descritores: audiologia, perda auditiva, surdez, transtornos da audição e Síndrome de Cornelia de Lange. Esta revisão foi cadastrada no Próspero, sob número CRD42020191481. Foram considerados para análise, estudos nacionais e internacionais, utilizando o direcionamento do acrônimo PECO. Para análise do risco de viés dos estudos, utilizou-se os protocolos do Instituto Joanna Briggs. Após isso, os estudos foram descritos e analisados. Resultados: dos 1.080 artigos encontrados, 12 atenderam aos critérios de inclusão. Nos resultados audiológicos, constatou-se que indivíduos com SCdL podem apresentar perda auditiva, sendo que o comprometimento pela perda auditiva condutiva foi o mais frequente, correspondendo a 49,20% dos indivíduos com SCdL avaliados, seguido pela perda auditiva neurossensorial (13,49%). O grau de perda auditiva variou de leve à profundo. Conclusão: indivíduos com SCdL frequentemente apresentam perda auditiva, decorrente principalmente de alterações de orelha média, com graus variando de leve a profundo.

Frequency-Following Response (FFR) in Military Pilots.

Introduction Good hearing in pilots, including central auditory skills, is critical for flight safety and the prevention of aircraft accidents. Pure tone audiometry alone may not be enough to assess hearing in the members of this population who, in addition to high noise levels, routinely face speech recognition tasks in non-ideal conditions. Objective To characterize the frequency-following response (FFR) of a group of military pilots compared with a control group. Methods Twenty military pilots in the Study Group and 20 non-pilot military personnel, not exposed to noise in their work, in the Control Group, all with normal hearing, aged between 30 and 40 years old, completed a questionnaire to assess their hearing habits, and their FFRs were measured with a /da/ syllable (duration 40 milliseconds, speed 10.9/s), at 80 dB NA in the right ear. All procedures were approved by the ethical committee of the institution. Statistical analysis was performed using the t-Student or Mann-Whitney tests for quantitative variables, and the Fisher or chi-squared tests for qualitative variables, and a value of p < 0.05 was considered to be statistically significant. Results There was no significant difference between the groups regarding auditory habits. In the FFR, wave amplitudes A ( p = 0.01) and C ( p = 0.04) were significantly lower in the Study Group. Conclusion Working as a military pilot can be a crucial factor in determining an individual's typical FFR pattern, demonstrated in the present study by statistically significant reductions in the amplitudes of the A and C waves.