Pediatric Ototoxicity: Current Trends and Management

Assessment and Management of Chemotherapy-Induced Ototoxicity in Children

Chemotherapy-induced ototoxicity is a significant concern in pediatric patients with cancer, particularly those treated with platinum-based agents, such as cisplatin and carboplatin. This study reviewed its prevalence, risk factors, early diagnosis, and management strategies. A literature review was conducted to assess the effects of ototoxic chemotherapy, screening methods, and treatment approaches. Various grading scales and rehabilitation strategies were analyzed. Platinum-based chemotherapy causes ototoxic hearing loss in approximately 100% of cases, including high-frequency and delayed-onset losses. Younger age, higher cumulative dose, and cranial irradiation increased the risk. Screening adherence remains suboptimal, despite guidelines recommending early detection through high-frequency audiometry. Sodium thiosulfate may reduce ototoxicity in nonmetastatic cases. If appropriate, hearing aids and cochlear implants can support communication and language development. Ototoxic hearing loss is a prevalent, yet underdiagnosed, complication of pediatric cancer treatment. Standardized screening, otoprotective strategies, and early rehabilitation are essential to minimize their impact on language and quality of life. Greater awareness and national guidelines are required to improve the care of pediatric cancer survivors.

Apigenin attenuates cisplatin-induced hair cell damage in the zebrafish lateral line

Cisplatin, a widely used chemotherapy drug, is notorious for causing ototoxicity, which leads to irreversible sensorineural hearing loss by damaging cochlear sensory hair cells (HCs), spiral ganglion neurons (SGNs), and the stria vascularis (SV). Mechanisms include DNA adduct formation, mitochondrial dysfunction, oxidative stress, and inflammation, ultimately triggering cell death pathways like apoptosis, necroptosis, pyroptosis, or ferroptosis. Apigenin, a natural flavonoid found in various foods and beverages, possesses antioxidant, anti-inflammatory, and anti-tumor properties. Despite these benefits, its potential to mitigate cisplatin-induced ototoxicity remains unexplored. To investigate, we administered varying concentrations of apigenin (1 μM, 20 μM, 100 μM, and 250 μM) alongside cisplatin (200 μM) to zebrafish larvae at 5 days post fertilization. Cisplatin significantly reduced lateral line HCs, impacting auditory function as shown in startle response tests. However, co-administration with apigenin preserved lateral line HCs and mitigated cisplatin-induced hearing loss. In larvae exposed to cisplatin, TUNEL assay confirmed significant HCs apoptosis, which apigenin effectively countered by suppressing reactive oxygen species accumulation in lateral line HCs. RNA-seq analysis highlighted apigenin's role in modulating apoptosis-related pathways, supporting its protective effects against cisplatin-induced ototoxicity. These findings underscore apigenin's potential as a crucial protective agent against cisplatin-induced ototoxicity, meriting further investigation for clinical applications.

A review of bilateral sudden sensorineural hearing loss in pediatric patients

OBJECTIVE

Bilateral, sudden sensorineural hearing loss (SSNHL) in the pediatric population is a rare phenomenon potentially detrimental to language acquisition and social development. This study comprehensively reviews and analyzes existing literature to determine any correlation or commonality in etiologies, presentations, and management of this condition.

METHODS

PubMed, Cochrane, Scopus, and Web of Science databases were systematically searched for articles related to pediatric SSNHL from 1970 to 2021. Case series, case reports, and cohort studies were included. Data on patient demographics, etiology, diagnostic testing, management, and hearing recovery were collected.

RESULTS

Excluding duplicates, 553 unique titles were identified by established search criteria, of which 342 titles were relevant to pediatric sudden hearing loss. Forty-six papers reported cases of bilateral SSNHL, totaling 145 individual cases. Not included in the analysis were 45 cases documented as non-organic hearing loss. The average age of the total 145 included patients was 8.5 years and 51 were male. Reported etiologies included cytomegalovirus (n = 3), meningitis (n = 13), mumps (n = 5), ototoxin exposure (n = 13), and enlarged vestibular aqueduct (n = 9). Tinnitus (n = 30) was the most reported concurrent symptom, followed by vertigo (n = 21). Systemic steroid therapy was the most common treatment and, when follow up was reported, most patients (51.2%) had complete or partial recovery of hearing.

CONCLUSIONS

This is a comprehensive review of pediatric bilateral SSNHL. Though often idiopathic, etiologies also include infectious, structural, and autoimmune. Treatment largely consists of systemic steroid therapy, with variables rates of recovery. Further studies on intratympanic administration of steroids may guide future treatment.

Ototoxicity in childhood: Recommendations of the CODEPEH (Commission for the Early Detection of Childhood Hearing Loss) for prevention and early diagnosis

Ototoxicity is defined as the damage, reversible or irreversible, produced in the inner ear by various substances that are called ototoxic and that can cause hearing loss and/or an alteration of the vestibular system. Permanent hearing loss significantly affects quality of life and is especially important in children. The lack or delay in its detection is frequent, since it often progresses in an inconspicuous manner until it affects communication and overall development. This impact can be minimized by following a strategy of audiological monitoring of ototoxicity, which allows for its early detection and treatment. This document recommends that children who are going to be treated with cisplatin or aminoglycosides be monitored. This CODEPEH review and recommendation document focuses on the early detection, prophylaxis, otoprotection, monitoring and treatment of ototoxicity caused by aminoglycosides and platinum-based antineoplastics in the paediatric population.

Adverse Audio-Vestibular Effects of Drugs and Vaccines Used in the Treatment and Prevention of COVID-19: A Review

(1) Background: The purpose of this article is to review pharmacological treatments for COVID-19 (currently approved by the EMA (European Medical Agency) and FDA (Food and Drug Administration)) and highlight their potential audio-vestibular side-effects as an ototoxic adverse reaction. (2) Methods: Review of the available literature in the scientific databases PubMed, ResearchGate, Scopus, and ScienceDirect, and in summaries of product data sheets. (3) Results: In accordance with EBM (evidence-based medicine) the treatment of COVID-19 by using lopinavir/ritonavir, chloroquine and hydroxychloroquine, azithromycin, favipiravir, amantadine, oseltamivir, and ivermectin is no longer recommended for patients suffering from COVID-19 due to a lack of clinical data, publications, and recommendations. There were 39 publications and 15 summaries of product characteristics (as other sources of data) which were also used in this analysis. Adverse events could be permanent or disappear over time. Following treatment for COVID-19, the most frequent adverse audio-vestibular reactions reported in clinical trials and publications in the area of audiology and otorhinolaryngology were: dizziness, blurry vision with dizziness, nasopharyngitis, dysgeusia, and tinnitus. As far as vaccines are concerned, dizziness as an ototoxic effect was uncommon and occurs only in hypersensitive people who experience anaphylactic shock. (4) Conclusions: The ototoxicity of the drugs discussed here does not have as severe symptoms as the drugs used in the treatment of COVID-19 in 2020 (e.g., hydroxychloroquine), and relates mainly to disorders of the vestibulocochlear system. However, there is still a need to monitor ototoxic side-effects because of potential interactions with other ototoxic drugs. Many of the drugs approved by EMA and FDA are new, and not every side-effect is known.

Ototoxicity in cancer survivors: Experience and proposal of a surveillance protocol

INTRODUCTION

Ototoxicity occurs in different percentages in patients after treatment with platinum-based chemotherapy or cranial radiation therapy. The aim of this study was to present our experience in ototoxicity monitoring.

MATERIAL AND METHODS

A review was made of the registry of paediatric cancer patients referred to the Children's Hearing Loss Unit from 1999 to 2019.

RESULTS

Of the 46 patients referred to this unit, 41 had received platinum as part of their treatment, 17 patients underwent neurosurgery, and 18 patients received cranial radiation therapy. An anamnesis and otoscopy were performed on all of them, and the monitoring was carried out with tone-verbal audiometry and/or distortion products. Hearing loss was observed in eight patients (21.05% of patients referred for audiological follow-up) as a consequence of the treatment. It was impossible to determine the audiological situation in eight patients at the end of treatment. Hearing aid adaption was necessary in two patients. In coordination with Paediatric Oncology, a change from cisplatin to carboplatin due to bilateral grade two ototoxicity was considered appropriate during treatment in one patient.

CONCLUSION

Adequate coordination with Paediatric Oncology is essential to carry out active surveillance for ototoxicity and to modify, if possible, the dosage or type of chemotherapy in case hearing is affected. In our experience, and following current recommendations, a pre-treatment assessment is usually performed, as well as monitoring during treatment, at the end of treatment, and annually thereafter due to the risk of a later development of hearing loss.

Naringin attenuates cisplatin- and aminoglycoside-induced hair cell injury in the zebrafish lateral line via multiple pathways

Exposure to ototoxic drugs is a significant cause of hearing loss that affects about 30 thousand children with potentially serious physical, social and psychological dysfunctions every year. Cisplatin (CP) and aminoglycosides are effective antineoplastic or bactericidal drugs, and their application has a high probability of ototoxicity which results from the death of hair cells (HCs). Here, we describe the therapeutic effect of the flavonoid compound naringin (Nar) against ototoxic effects of cisplatin and aminoglycosides include gentamicin (GM) and neomycin (Neo) in zebrafish HCs. Animals incubated with Nar (100‐400 μmol/L) were protected against the pernicious effects of CP (150‐250 μmol/L), GM (50‐150 μmol/L) and Neo (50‐150 μmol/L). We also provide evidence for the potential mechanism of Nar against ototoxicity, including antioxidation, anti‐apoptosis, promoting proliferation and hair cell regeneration. We found that mRNA levels of the apoptotic‐ and pyroptosis‐related genes are regulated by Nar both in vivo and in vitro. Finally, by proving that Nar does not affect the anti‐tumour efficacy of CP and antibacterial activity of aminoglycosides in vitro, we highlight its value in clinical application. In conclusion, these results unravel a novel therapeutic role for Nar as an otoprotective drug against the adverse effects of CP and aminoglycosides.

[Ototoxicity in cancer survivors: experience and proposal of a surveillance protocol]

INTRODUCTION

Ototoxicity occurs in different percentages in patients after treatment with platinum-based chemotherapy or cranial radiation therapy. The aim of this study was to present experience in ototoxicity monitoring.

MATERIAL AND METHODS

A review was made of the registry of paediatric cancer patients referred to the Children's Hearing Loss Unit from 1999 to 2019.

RESULTS

Of the 46 patients referred to this unit, 41 had received platinum as part of their treatment, 17 patients underwent neurosurgery, and 18 patients received cranial radiation therapy. An anamnesis and otoscopy were performed on all of them, and the monitoring was carried out with tone-verbal audiometry and/or distortion products. Hearing loss was observed in eight patients (21.05% of patients referred for audiological follow-up) as a consequence of the treatment. It was impossible to determine the audiological situation in eight patients at the end of treatment. Hearing aid adaption was necessary in two patients. In coordination with Paediatric Oncology, a change from cisplatin to carboplatin due to bilateral grade two ototoxicity was considered appropriate during treatment in one patient.

CONCLUSION

Adequate coordination with Paediatric Oncology is essential to carry out active surveillance for ototoxicity and to modify, if possible, the dosage or type of chemotherapy in case hearing is affected. In our experience, and following current recommendations, a pre-treatment assessment is usually performed, as well as monitoring during treatment, at the end of treatment, and annually thereafter due to the risk of a later development of hearing loss.

Noise: Acoustic Trauma and Tinnitus, the US Military Experience

Tinnitus is commonly experienced by military Service Members and Veterans, especially by the newest generation who served in Iraq and Afghanistan. When patients seek health care for tinnitus, it is important to determine its type, check for comorbid conditions that might be triggering or exacerbating the condition, and to address its functional and psychosocial effects. Otolaryngologists are usually the first health care professional to evaluate a patient with tinnitus, and it is essential to provide appropriate referrals for this high-burden condition. Noise-induced tinnitus is multifaceted; by performing a thorough assessment, appropriate action can be taken to best meet the needs of patients.

Astaxanthin-loaded polymer-lipid hybrid nanoparticles (ATX-LPN): assessment of potential otoprotective effects

Background

Ototoxicity is one of the major side effects of platinum-based chemotherapy, especially cisplatin therapy. To date, no FDA approved agents to alleviate or prevent this ototoxicity are available. However, ototoxicity is generally believed to be produced by excessive generation of reactive oxygen species (ROS) in the inner ear, thus leading to the development of various antioxidants, which act as otoprotective agents. Astaxanthin (ATX) is an interesting candidate in the development of new therapies for preventing and treating oxidative stress-related pathologies, owing to its unique antioxidant capacity.

Methods and results

In this study, we aimed to evaluate the potential antioxidant properties of ATX in the inner ear by using the HEI-OC1 cell line, zebrafish, and guinea pigs. Because ATX has poor solubility and cannot pass through round window membranes (RWM), we established lipid-polymer hybrid nanoparticles (LPN) for loading ATX. The LPN enabled ATX to penetrate RWM and maintain concentrations in the perilymph in the inner ear for 24 h after a single injection. ATX-LPN were found to have favorable biocompatibility and to strongly affect cisplatin-induced generation of ROS, on the basis of DCFHDA staining in HEI-OC1 cells. JC-1 and MitoTracker Green staining suggested that ATX-LPN successfully reversed the decrease in mitochondrial membrane potential induced by cisplatin in vitro and rescued cells from early stages of apoptosis, as demonstrated by FACS stained with Annexin V-FITC/PI. Moreover, ATX-LPN successfully attenuated OHC losses in cultured organ of Corti and animal models (zebrafish and guinea pigs) in vivo. In investigating the protective mechanism of ATX-LPN, we found that ATX-LPN decreased the expression of pro-apoptotic proteins (caspase 3/9 and cytochrome-c) and increased expression of the anti-apoptotic protein Bcl-2. In addition, the activation of JNK induced by CDDP was up-regulated and then decreased after the administration of ATX-LPN, while P38 stayed unchanged.

Conclusions

To best of our knowledge, this is first study concluded that ATX-LPN as a new therapeutic agent for the prevention of cisplatin-induced ototoxicity.