Neuroprotection Role of Vitamin C by Upregulating Glutamate Transporter-1 in Auditory Cortex of Noise-Induced Tinnitus Animal Model.

Vitamin C (Vc) plays a pivotal role in a series of pathological processes, such as tumors, immune diseases, and neurological disorders. However, its therapeutic potential for tinnitus management remains unclear. In this study, we find that Vc relieves tinnitus in noise-exposed rats. In the 7-day therapy groups, spontaneous firing rate (SFR) increases from 1.17 ± 0.10 Hz to 1.77 ± 0.15 Hz after noise exposure. Vc effectively reduces the elevated SFR to 0.99 ± 0.07 and 0.55 ± 0.05 Hz at different doses. The glutamate level in auditory cortex of noise-exposed rats (3.78 ± 0.42 µM) increases relative to that in the control group (1.34 ± 0.22 µM). High doses of Vc (500 mg/kg/day) effectively reduce the elevated glutamate levels (1.49 ± 0.28 µM). Mechanistic studies show that the expression of glutamate transporter 1 (GLT-1) is impaired following noise exposure and that Vc treatment effectively restores GLT-1 expression in the auditory cortex. Meanwhile, the GLT-1 inhibitor, dl-threo-beta-benzyloxyaspartic acid (dl-TBOA), invalidates the protection role of Vc. Our finding shows that Vc substantially enhances glutamate clearance by upregulating GLT-1 and consequently alleviates noise-induced tinnitus. This study provides valuable insight into a novel biological target for the development of therapeutic interventions that may prevent the onset of tinnitus.

Self-reporting of hearing loss and tinnitus in the diagnosis of ototoxicity by meglumine antimoniate in patients treated for American tegumentary Leishmaniasis.

INTRODUCTION: American Tegumentary Leishmaniasis (ATL) treatment is based on pentavalent antimonials (Sb5+), but these drugs have been associated to several adverse effects. Hearing loss and tinnitus during treatment with meglumine antimoniate (MA) have already been reported. This study aimed to describe the usefulness of self-reporting of hearing loss and tinnitus in diagnosing MA-induced ototoxicity. METHODS: A prospective longitudinal study was conducted with 102 patients with parasitological diagnosis of ATL, treated with different MA schemes. The presence of clinical auditory toxicity was defined as the emergence or worsening of self-reporting hearing loss and/or tinnitus during monitoring. Measures of sensitivity, specificity, and the positive and negative predictive value of the patient's self-reporting of hearing loss and tinnitus in relation to the result of the audiometric test (considered the gold standard) were calculated. RESULTS: The age of the evaluated patients ranged from 15 to 81 years, with a median of 41 years, and most were male (73.5%). Seventy-five patients (73.5%) had cutaneous leishmaniasis and 27 (26.5%) mucosal leishmaniasis. Eighty-six patients (84.3%) received intramuscular (IM) treatment and 16 (15.7%) were treated with intralesional MA. During treatment, 18 (17,6%) had tinnitus and 7 (6,9%) had complaint of hearing loss. 53 (52%) patients had cochlear toxicity confirmed by tone threshold audiometry and high frequency audiometry, from which 60% received a dose of 20 mg Sb5+/kg/day (p = 0.015) and 96.2% were treated with IM MA (p = 0.001). Tinnitus has greater specificity and positive predictive value than hearing loss, with a low number of false positives, but with a high false negative value. CONCLUSION: Although the large number of false negatives suggests that self-report of hearing loss or tinnitus cannot be considered a good screening test for referring the patient to an audiometry, the low number of false positives suggests the need to value the patient's complaint for referral. Otherwise, this study reinforces the importance of audiological monitoring during treatment with MA, especially in those patients with self-reporting of hearing loss or tinnitus when treated with 20 mg Sb5+/kg/day via IM.

Repurposing metformin to manage idiopathic or long COVID Tinnitus: self-report adopting a pathophysiological and pharmacological approach.

Chronic tinnitus is a common neurological disorder that affects millions of patients globally with no available successful pharmacotherapy. It can be extremely bothersome to some patients to the extent that it occasionally qualifies as a disability that can hinder them from leading a normal life. In this short communication, the author discusses how he suffered from idiopathic tinnitus and how he managed to adopt a combined pathophysiological and pharmacological approach to the reason for the first time in the medical literature that low-dose metformin might be safely and effectively repurposed to manage at least a subset of tinnitus patients while discussing the potential role of adenosine receptor agonists as potential future tinnitus therapeutics.

The potassium channels: Neurobiology and pharmacology of tinnitus.

Tinnitus is a widespread public health issue that imposes a significant social burden. The occurrence and maintenance of tinnitus have been shown to be associated with abnormal neuronal activity in the auditory pathway. Based on this view, neurobiological and pharmacological developments in tinnitus focus on ion channels and synaptic neurotransmitter receptors in neurons in the auditory pathway. With major breakthroughs in the pathophysiology and research methodology of tinnitus in recent years, the role of the largest family of ion channels, potassium ion channels, in modulating the excitability of neurons involved in tinnitus has been increasingly demonstrated. More and more potassium channels involved in the neural mechanism of tinnitus have been discovered, and corresponding drugs have been developed. In this article, we review animal (mouse, rat, hamster, and guinea-pig), human, and genetic studies on the different potassium channels involved in tinnitus, analyze the limitations of current clinical research on potassium channels, and propose future prospects. The aim of this review is to promote the understanding of the role of potassium ion channels in tinnitus and to advance the development of drugs targeting potassium ion channels for tinnitus.

Increased risk of hearing loss associated with macrolide use: a systematic review and meta-analysis.

The increased risk of hearing loss with macrolides remains controversial. We aimed to systematically review and meta-analyze data on the clinical risk of hearing loss, tinnitus, and ototoxicity following macrolide use. A systematic search was conducted across PubMed, MEDLINE, Cochrane, and Embase databases from database inception to May 2023. Medical Subject Heading (MeSH) terms and text keywords were utilized, without any language restrictions. In addition to the electronic databases, two authors manually and independently searched for relevant studies in the US and European clinical trial registries and Google Scholar. Studies that involved (1) patients who had hearing loss, tinnitus, or ototoxicity after macrolide use, (2) intervention of use of macrolides such as azithromycin, clarithromycin, erythromycin, fidaxomicin, roxithromycin, spiramycin, and/or telithromycin, (3) comparisons with specified placebos or other antibiotics, (4) outcomes measured as odds ratio (OR), relative risk (RR), hazard ratio (HR), and mean difference for ototoxicity symptoms using randomized control trial (RCT)s and observational studies (case-control, cross-section, and cohort studies) were included. Data extraction was performed independently by two extractors, and a crosscheck was performed to identify any errors. ORs along with their corresponding 95% confidence intervals (CIs) were estimated using random-effects models. The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines for RCTs and Meta-Analysis of Observational Studies in Epidemiology guidelines for observational studies were followed. We assessed the hearing loss risk after macrolide use versus controls (placebos and other antibiotics). Based on data from 13 studies including 1,142,021 patients (n = 267,546 for macrolide and n = 875,089 for controls), the overall pooled OR was 1.25 (95% CI 1.07-1.47). In subgroup analysis by study design, the ORs were 1.37 (95% CI 1.08-1.73) for RCTs and 1.33 (95% CI 1.24-1.43) for case-control studies, indicating that RCT and case-control study designs showed a statistically significant higher risk of hearing loss. The group with underlying diseases such as multiple infectious etiologies (OR, 1.16 [95% CI 0.96-1.41]) had a statistically significant lower risk than the group without (OR, 1.53 [95% CI 1.38-1.70] P = .013). The findings from this systematic review and meta-analysis suggest that macrolide antibiotics increase the risk of hearing loss and that healthcare professionals should carefully consider this factor while prescribing macrolides.

In Silico Study in MPO and Molecular Docking of the Synthetic Drynaran Analogues Against the Chronic Tinnitus: Modulation of the M1 Muscarinic Acetylcholine Receptor.

Tinnitus is a syndrome that affects the human auditory system and is characterized by a perception of sounds in the absence of acoustic stimuli, or in total silence. Research indicates that muscarinic acetylcholine receptors (mAChRs), especially the M1 type, have a fundamental role in the alterations of auditory perceptions of tinnitus. Here, a series of computer-aided tools were used, from molecular surface analysis software to services available on the web for estimating pharmacokinetics and pharmacodynamics. The results infer that the low lipophilicity ligands, that is, the 1a-d alkyl furans, present the best pharmacokinetic profile, as compounds with an optimal alignment between permeability and clearance. However, only ligands 1a and 1b have properties that are safe for the central nervous system, the site of cholinergic modulation. These ligands showed similarity with compounds deposited in the European Molecular Biology Laboratory chemical (ChEMBL) database acting on the mAChRs M1 type, the target selected for the molecular docking test. The simulations suggest that the 1 g ligand can form the ligand-receptor complex with the best affinity energy order and that, together with the 1b ligand, they are competitive agonists in relation to the antagonist Tiotropium, in addition to acting in synergism with the drug Bromazepam in the treatment of chronic tinnitus.

Essential Palatal Myoclonus and Clicking Tinnitus in a Nine-Year-Old Boy-A Case Report.

The work describes a case of palatal myoclonus with distressing tinnitus in a 9-year-old boy and its successful treatment with injections of botulinum toxin. This case report discusses common questions about myoclonic-induced clicking tinnitus and provides answers. Laryngoscope, 134:397-399, 2024.

The effect of vitamin B12 on idiopathic tinnitus.

INTRODUCTION: Tinnitus is one of the most important challenges in the field of ear, nose and throat diseases. The aim of this study was to evaluate the effect of vitamin B12 on idiopathic tinnitus. MATERIAL AND METHODS: In this double-blind clinical trial study, 140 patients with idiopathic tinnitus were divided into two groups, the group receiving vitamin B12 and the group receiving placebo. The first group received vitamin B12 for a month and the other group received placebo. All patients filled a THI questionnaire before the participation, one month and three months after the participation. VAS evaluation questionnaires were also filled for the patients before the participation, one month and three months after the participation. The effect of vitamin B12 on tinnitus was also assessed according to hearing loss status. The two groups were also compared regarding the side effects. RESULTS: There was no significant differences between two groups regarding age (p.value = 0.523), gender (females (p.value = 0.810) and males (p.value = 0.789), and hearing loss status (p value = 0.651). According to VAS score, there was no significant statistical differences in tinnitus severity in each group (B12 group, p.value = 0.851 and placebo group, p.value = 0.386). There was no significant statistical differences in tinnitus severity based on VAS score between two groups before the participation (p.value = 0.560), one month (p.value = 0.485) and three months (p.value = 0.254) after the participation. According to THI criterion, there was no significant statistical differences in tinnitus severity in each group (B12 group, p.value = 0.259 and placebo group, p.value = 0.521). There was no significant statistical differences in tinnitus severity based on THI score between two groups before the participation (p.value = 0.651), one month (p.value = 0.125) and three months (p.value = 0.089) after the participation. None of the patients of the two groups had any noticeable side effects. The mean of VAS and THI also had no statistically significant difference before and after the intervention in term of hearing loss status (p.value>0.05). These results were not significantly different between the two groups in term of hearing loss status (p value>0.05). CONCLUSION: The result of this study indicated that vitamin B12 has no distinctive effect on reducing tinnitus severity.

Response to OKN-007 and NAC in a Patient with Unilateral Hearing Loss and Chronic Tinnitus from Vestibular Schwannoma.

BACKGROUND: Tinnitus is the perception of sound in the absence of external acoustic stimulation. Being one of the most common diseases of the ear, it has a global prevalence ranging from 4.1 to 37.2%. To date, it has been difficult to treat tinnitus as its pathophysiology is poorly understood and there are limited treatment options. OBJECTIVE: To investigate the effect of OKN-007 (also known as HPN-07), a nitrone-based investigational drug, in combination with oral N-acetylcycsteine (NAC), for the treatment of hearing loss and chronic tinnitus under an individual expanded access protocol. PATIENT CASE: We report the case of a patient who presented with left-sided ear fullness, mild tinnitus, and mild high frequency sensorineural hearing loss with 100% word recognition. A large enhancing mass seen on MRI revealed a vestibular schwannoma. He underwent subtotal resection of the tumor resulting in a moderate-to-profound sensorineural hearing loss and catastrophic tinnitus. The patient was treated with intravenous OKN-007 at 60 mg/kg dosed three times per week and oral NAC 2500 mg twice daily. RESULTS: Post-treatment audiometric testing revealed an average of 16.66 dB in hearing threshold improvement in three frequencies (125, 250 and 500 Hz) with residual hearing in the affected left ear. His tinnitus loudness matching improved from 90 dB to 19 dB post-treatment. His Tinnitus Handicap Inventory improved from 86/100 (Catastrophic) to 40/100 (Moderate). He also experienced improvements in sleep, concentration, hearing, and emotional well-being, and reported significantly decreased levels of tinnitusrelated distress. CONCLUSIONS: This case report highlights the feasibility and therapeutic potential of the combination of OKN-007 and NAC in treating hearing loss and tinnitus that warrants further investigation.

Personalized music therapy combined with medication as treatment for tinnitus.

OBJECTIVE: This study aimed to investigate the effects of personalized music therapy in combination with medication as a treatment for tinnitus. PATIENTS AND METHODS: We retrospectively analyzed a total of 200 patients who were admitted to the Department of Otorhinolaryngology in our hospital from June 2018 to June 2019, with tinnitus as their primary complaint. Patients were divided into four groups based on their individual treatment methods: medication group (patients received medication only, n=40), tinnitus masking (TM) group (patients received medication plus TM, n=38), tinnitus re-training (TRT) group (patients received medication plus TRT, n=35), and personalized group (patients received medication plus personalized music therapy, n=30). The pure-tone audiometry (PTA), loudness visual analogue scale (VAS), and tinnitus handicap inventory (THI) for each patient were analyzed. RESULTS: There were statistically significant differences in the THI and VAS scores of all groups before and after treatment (p<0.05). Following nine and twelve months of treatment, the THI and VAS scores of the TRT group and the personalized group were significantly lower than those of the other two groups (p<0.05). The THI and VAS scores of the personalized group were significantly lower than those of the TRT group (p<0.05). Additionally, THI and VAS scores were statistically different at various measurement time points in each group (p<0.05). The clinical effective rate (85.37%) of the personalized group was higher than that of the other three groups (p<0.05). CONCLUSIONS: TM, TRT, or personalized music therapy, when combined with medication, are effective in treating patients with tinnitus. Among these methods, personalized music therapy may be the superior treatment after nine months of treatment.

Alterations of auditory sensory gating in mice with noise-induced tinnitus treated with nicotine and cannabis extract.

Tinnitus is a phantom sound perception affecting both auditory and limbic structures. The mechanisms of tinnitus remain unclear and it is debatable whether tinnitus alters attention to sound and the ability to inhibit repetitive sounds, a phenomenon also known as auditory gating. Here we investigate if noise exposure interferes with auditory gating and whether natural extracts of cannabis or nicotine could improve auditory pre-attentional processing in noise-exposed mice. We used 22 male C57BL/6J mice divided into noise-exposed (exposed to a 9-11 kHz narrow band noise for 1 h) and sham (no sound during noise exposure) groups. Hearing thresholds were measured using auditory brainstem responses, and tinnitus-like behavior was assessed using Gap prepulse inhibition of acoustic startle. After noise exposure, mice were implanted with multi-electrodes in the dorsal hippocampus to assess auditory event-related potentials in response to paired clicks. The results showed that mice with tinnitus-like behavior displayed auditory gating of repetitive clicks, but with larger amplitudes and longer latencies of the N40 component of the aERP waveform. The combination of cannabis extract and nicotine improved the auditory gating ratio in noise-exposed mice without permanent hearing threshold shifts. Lastly, the longer latency of the N40 component appears due to an increased sensitivity to cannabis extract in noise-exposed mice compared to sham mice. The study suggests that the altered central plasticity in tinnitus is more sensitive to the combined actions on the cholinergic and the endocannabinoid systems. Overall, the findings contribute to a better understanding of pharmacological modulation of auditory sensory gating.

Intratympanic dexamethasone in Manières disease and symptom control.

BACKGROUND: Manières disease (MD) is a chronic inner ear disease characterized by recurrent vertigo and fluctuation in auditory symptoms. Vertigo spells have a sudden onset and are difficult for patients to handle. Therefore, treating a patient with MD is still a challenge for clinicians. AIMS: This study aims to analyse the short-term effects of intratympanic dexamethasone (ITD) on the various symptoms of unilateral MD. MATERIALS AND METHODS: The study comprised 27 patients with unilateral MD and severe vertigo who failed medication therapy. Treatment was with ITD as an alternative to destructive therapy. Treatment is evaluated after four months. RESULTS: Significant improvements were measured with Dizziness Handicap Inventory (DHI), Tinnitus Handicap Inventory (THI), frequency of vertigo attacks longer than 20 min, Functional Level Scale (FLS), and tinnitus sensation measured by the Analog Visual Scale (AVS). Patients with severe symptoms grading with DHI and THI experienced the most improvement. Patients have achieved substantial vertigo control in 73%. CONCLUSION: ITD application shows improvement in controlling vertigo and tinnitus in patients under exacerbation in MD. SIGNIFICANCE: It is a promising non-destructive addition to the 'stepwise treatment concept' in MD and can be used as a first-line treatment in vertigo control.

[Intratympanic Drug Application - Indication and Procedure]. / Intratympanale Medikamentenapplikation ­ Indikationen und Ablauf.

Neurootologic disorders of the inner ear associated with symptoms such as tinnitus, vertigo, and hearing loss are common and often cause significant distress to affected patients. Treatment options are usually limited. There are now some indications for which intratympanic drug application is a possible treatment option. Intratympanic drug administration is a simple, inexpensive therapy option with few side effects that can be used on an outpatient basis. Therefore, it should not be disregarded when indicated.

Auditory cortex hyperconnectivity before rTMS is correlated with tinnitus improvement / Correlación entre hiperconectividad de la corteza auditiva antes del tratamiento con estimulación magnética transcraneal repetitiva y mejoría de los acúfenos

Introduction: Repetitive transcranial magnetic stimulation (rTMS) has been used as a potential treatment for tinnitus; however, its effectiveness is variable and unpredictable. We hypothesized that resting-state functional connectivity before rTMS may be correlated with rTMS treatment effectiveness. Methods: We applied 1-Hz rTMS to the left primary auditory (A1) and dorsolateral prefrontal cortices (DLPFC) of 10 individuals with tinnitus and 10 age-matched controls. Resting-state functional magnetic resonance imaging (fMRI) studies were performed approximately one week before rTMS. Seed-based connectivity analyses were conducted for each individual, with seed regions as rTMS target areas. Results: Compared to controls, the left superior temporal areas showed significantly increased positive connectivity with the left A1 and negative connectivity with the left DLPFC in the tinnitus group. The left frontoparietal and right cerebellar areas showed significantly increased negative connectivity with the left A1 and positive connectivity with the left DLPFC. Seed-based hyperconnectivity was correlated with tinnitus improvement (pre-rTMS vs. 2-week post-rTMS Tinnitus Handicap Inventory scores). Tinnitus improvement was significantly correlated with left A1 hyperconnectivity; however, no correlation was observed with left DLPFC connectivity. Positive rTMS outcomes were associated with significantly increased positive connectivity in bilateral superior temporal areas and significantly increased negative connectivity in bilateral frontal areas. Conclusions: Our results suggest that oversynchronisation of left A1 connectivity before rTMS of the left A1 and DLPFC is associated with treatment effectiveness.(AU)

Introducción: La estimulación magnética transcraneal repetitiva (EMTr) se ha utilizado como posible tratamiento para los acúfenos, aunque su efectividad es variable e impredecible. Planteamos la hipótesis de que existe una correlación entre la conectividad funcional en estado de reposo antes de aplicar EMTr y la efectividad de dicho tratamiento. Métodos: Aplicamos EMTr a 1 Hz sobre la corteza auditiva primaria (A1) y la corteza prefrontal dorsolateral (CPFDL) izquierdas de 10 pacientes con acúfenos y 10 controles del mismo rango de edad. Se realizaron estudios de resonancia magnética funcional (RMF) en estado de reposo de todos los pacientes aproximadamente una semana antes de la EMTr. En cada caso, se construyó un mapa de conectividad basado en las ROIs, en el que las ROIs eran las áreas que se tratarían con la EMTr. Resultados: La región temporal superior izquierda mostró una conectividad positiva significativamente mayor con el área A1 izquierda y mayor conectividad negativa con la CPFDL izquierda en los pacientes con acúfenos que en los controles. Además, las áreas frontoparietal izquierda y cerebelar derecha mostraron una conectividad negativa significativamente superior con el área A1 izquierda y mayor conectividad positiva con la CPFDL izquierda. La hiperconectividad de las ROIs se correlacionó con mejoría de los acúfenos según las puntuaciones pre-EMTr y 2 semanas post-EMTr en la escala Tinnitus Handicap Inventory. La mejoría de los acúfenos se correlacionó de manera significativa con la hiperconectividad del área A1 izquierda; sin embargo, no se encontró correlación con la conectividad de la CPFDL izquierda. El resultado favorable del tratamiento con EMTr se asocia con una mayor conectividad positiva en áreas temporales superiores de ambos hemisferios y con mayor conectividad negativa en áreas frontales bilaterales...(AU)

Effects of Oral Steroids Combined with Postauricular Steroid Injection on Patients with Sudden Sensorineural Hearing Loss with Delaying Intervention: A Retrospective Analysis.

Background: In the otology clinic, we often receive some sudden sensorineural hearing loss (SSNHL) patients accompanied by annoying tinnitus, who usually visited over three weeks after the onset. Nevertheless, due to the high treatment cost and relatively low cure rate, there are still great disputes about hospitalization or not for these patients. Aim: This study aimed to perform a retrospective analysis for analyzing the efficacy of treatment with oral steroids combined with postauricular steroid injection in patients with delaying effective treatment. Material/Methods: A total of 157 eligible SSNHL patients with delaying effective treatment over three weeks were enrolled in this study. According to different treatment methods of oral steroids with or without postauricular steroid injection, these patients were divided into three groups: PO (prednisone oral) group, PSI (prednisone oral and postauricular steroid injection) group, and PII (prednisone oral and postauricular lidocaine injection) group. The changes in level of hearing, mean subjective tinnitus loudness, and side effects were analyzed in the three groups. Results: Hearing improvement and tinnitus remission were all observed in three groups after treatment. Compared with PO and PII groups, those patients in PSI groups had more improvement in level of hearing and mean subjective tinnitus. The level of tinnitus loudness was statistically significantly correlated with the level of PTA both before treatment and after treatment. Conclusion: Oral steroids combined with postauricular steroid injection should be employed for treatment of SSNHL patients with delaying effective treatment over three weeks.

Discriminant Analysis of the Prognostic Factors for Hearing Outcomes in Patients with Idiopathic Sudden Sensorineural Hearing Loss.

BACKGROUND: This study aims to determine and assess prognostic variables that might affect the hearing result in patients with idiopathic sudden sensorineural hearing loss following intratympanic steroid injection. METHODS: In total, 190 patients with idiopathic sudden sensorineural hearing loss received intratympanic steroid injection. Two hearing indices (recovery and nonrecovery) will be analyzed as dependent variables; patient's age, time period between the onset of hearing loss and treatment, initial level of hearing (hearing loss pre), type of audiogram curve (upsloping, downsloping, and flat), presence of vertigo, presence of tinnitus, and diabetes) will be analyzed as prognostic factor variables. RESULTS: Recovery was seen in 72% of the patients. Different preinjection audiogram curves and hearing grades had a significant effect on recovery, absence of vestibular symptoms and no diabetic history were noted to have a good prognosis. Delay in treatment by more than 30 days from the onset of hearing loss was associated with a worse prognosis. CONCLUSION: Idiopathic sudden sensorineural hearing loss associated with late treatment plan more than 1 month, presence of vertigo, diabetes, and profound prehearing loss were negative prognostic factors. Whereas age, gender, and presence of tinnitus did not affect prognosis. More stable response was obtained when intratympanic steroids were added within 1 month after diagnosis, and the patient presented with mild or moderate hearing loss grade, flat or downsloping pure tone audiometery curve, and absence of vertigo and nondiabetic with significantly good results.

A randomized, double-blind, placebo-controlled phase 2 study of intratympanic OTO-313 in patients with moderate to severe subjective tinnitus.

PURPOSE: This was a randomized, double-blind, placebo-controlled Phase 2 study to evaluate the efficacy and safety of intratympanic OTO-313 in patients with subjective unilateral tinnitus. METHODS: Patients with moderate to severe unilateral tinnitus of 2-12 months duration were enrolled. A single intratympanic injection of OTO-313 or placebo was administered to the affected ear and patients were evaluated during a 16-weeks follow-up period. Efficacy was assessed using the Tinnitus Functional Index (TFI), daily ratings of tinnitus loudness and annoyance, and Patient Global Impression of Change (PGIC). RESULTS: Intratympanic administration of OTO-313 and placebo produced reductions in tinnitus with a similar percentage of TFI responders at Weeks 4, 8, 12, and 16. Reductions in daily ratings of tinnitus loudness and annoyance, and PGIC scores were also similar between OTO-313 and placebo groups. No significant differences in mean TFI scores between OTO-313 and placebo were observed for pre-specified strata regarding tinnitus duration (≥ 2 to ≤ 6 months and > 6 to ≤ 12 months) and TFI baseline scores (≥ 32 to ≤ 53 points and ≥ 54 to 100 points), although the results numerically favored OTO-313 in patients in the ≥ 2 to ≤ 6 months strata. These results also demonstrated an unexpectedly high placebo response particularly amongst patients with chronic tinnitus, despite training implemented to mitigate placebo response. OTO-313 was well-tolerated with a similar incidence of adverse events compared to placebo. CONCLUSIONS: OTO-313 did not demonstrate a significant treatment benefit relative to placebo due in part to a high placebo response. OTO-313 was safe and well-tolerated.

Experience of sudden sensorineural hearing loss following a mild COVID-19 infection.

A woman in her 30s was referred to an otolaryngologist with an acute onset of aural fullness, noise sensitivity, unilateral sudden onset hearing loss, vertigo and tinnitus. She had a confirmed COVID-19 infection 5 weeks prior. A pure tone audiogram confirmed sensorineural hearing loss. MRI identified an empty sella of the pituitary gland and without an obvious cause for hearing loss. Oral prednisolone and betahistine were prescribed, and her audiovestibular symptoms slowly improved over the subsequent months. The patient continues to experience intermittent tinnitus.

Intratympanic Botulinum Toxin Injection as a New Therapeutic Modality for Middle Ear Myoclonic Tinnitus.

OBJECTIVE: Middle ear myoclonic tinnitus (MEMT) is a disease caused by myoclonus or abnormal contractive movement of middle ear muscles (MEMs). This translational study was conducted to propose intratympanic botulinum toxin (IT-BTX) injection as a new therapeutic modality to treat MEMT. STUDY DESIGN: Animal experiment and nonrandomized controlled clinical trial. SETTING: Laboratory and medical center of an academic tertiary medical institution. METHODS: For the animal study, male Sprague-Dawley rats were divided into 4 subgroups according to the sacrificing day after IT-BTX injection. After initial hearing tests, randomly assigned experimental ears were intratympanically injected with 1 unit/100 µL of BTX-A, whereas control ears were injected with normal saline. Changes in the hearing thresholds, morphometry of the cochleae, electron microscopy study, and immunofluorescence analysis of MEMs were evaluated. For the human study, 10 intractable MEMT patients were enrolled. The hearing thresholds and the degree of tinnitus distress were observed for changes after IT-BTX injection. All patients were followed up for 3 months. RESULTS: As for the animal study, there were no significant changes in hearing thresholds and cochlear morphologies in all 4 subgroups of the rats. Significant MEM degenerations and immuno-detection of cleaved synaptosome-associated protein of 25 kDa (cSNAP-25) indicated the efficacy of IT-BTX. MEMT patients enrolled for the pilot clinical trial showed statistically significant improvement in tinnitus after IT-BTX injection. No major complications were noted. CONCLUSION: The new therapeutic modality of IT-BTX injection for the treatment of MEMT seems highly promising with an excellent result.

The effect of lidocaine iontophoresis for the treatment of tinnitus: a systematic review.

PURPOSE: Tinnitus is a common symptom with multiple causes and treatment options. Previous studies have investigated the effect of lidocaine iontophoresis. The aim of this review is to systematically present the effects on tinnitus and to derive possible effects. METHODS: In accordance to the PRISMA statement, the search and analysis were performed. An abstract in German or English and a performed intervention with lidocaine iontophoresis for the treatment of tinnitus, independent of the study design, were considered as inclusion criteria. Due to the heterogeneity of the studies, only a narrative synthesis was performed. RESULTS: The search yielded 179 studies of which 170 were excluded. Six full-texts and three abstracts were included. In total, 957 patients were treated with lidocaine iontophoresis. The percent improvement in symptoms after lidocaine iontophoresis ranged from 4% to 62%. The qualitative assessment of the studies resulted in an overall "weak" rating for all of them. CONCLUSIONS: Due to the heterogeneity and the limited quality of the studies found, no clear statement can be made about the efficacy. The number of those who benefited from therapy varied widely. In addition, it cannot be ruled out that the effect was merely due to electrical stimulation of the cochlea.