Ototoxicity as a preventable cause of inner ear disease- Is the Audiology profession doing enough to actually achieve this?

Contact Name: Ghada Al-Malky, PhD

Contact Email: g.al-malky@ucl.ac.uk

Dr. Al-Malky specialized in Audio-vestibular medicine in 1996 at the Faculty of Medicine, Alexandria University, Egypt, where she completed her Master’s Degree in 1999. She then moved to the UK in 2000 where she worked in the NHS at Glan Clwyd Hospital, North Wales for several years before taking up an academic role at the Ear Institute, UCL, London, where she is currently a Senior Lecturer. Dr. Al-Malky’s research interests include: * Translational research aiming at bridging the gap between laboratory auditory biophysics and genetics research and clinical applications in human patients. * The verification of the clinical usefulness of the continuous advances in auditory rehabilitation and establishing how they could be best utilized to improve patients’ quality of life. Her current specific research is related to investigating ototoxicity in children from an audiological, genetic susceptibility and clinical impact perspective. One of her major future aims is to establish collaborations to enhance the role of the UK audiology profession in the provision of ototoxicity monitoring and to help establish UK guidelines and standards of care for the management of patients with ototoxicity.

Ototoxicity is damage to the ear following exposure to drugs or chemicals. The inner ear is the commonest site of damage where cochlear and/or vestibular functions are affected. Ototoxic medications can cause irreversible toxicity, with aminoglycosides (AGs) and cisplatin being the most established agents. This side effect and others, such as nephrotoxicity, have limited the use of these treatments to patient groups that have to use them such as oncology and cystic fibrosis (CF) patients. A series of studies are reported in this presentation under three main themes. Theme A focused on audiological assessments and assessment tools; Theme B focused on causation; and Theme C focused on the impact of ototoxicity and current service provision.

Within the Theme A studies, audiological assessment of children with CF exposed to repeated aminoglycosides showed a higher prevalence of ototoxicity (24%) than previously reported in the literature. The studies also showed that the use of a test battery including extended high frequency audiometry (EHF-PTA) and distortion-product otoacoustic emissions (DPOAEs) was better at identifying early signs of ototoxicity than the use of standard audiometry alone and highlighted the importance of using universally accepted criteria for identification of ototoxicity. Theme B studies identified risk factors to ototoxicity such as cumulative exposure, older age, poorer lung function and presence of genetic mutations associated with increased susceptibility to ototoxicity (such as the A1555G mutation in the mitochondrial DNA). A rare case with normal hearing despite having the A1555G mutation and evidence of AG exposure was also discovered. The Theme C studies confirmed that presence of ototoxicity had a significant effect on the quality of life of children surviving cancer and showed that there was wide variation between the understanding and practices of clinicians managing ototoxic patients, such as oncologists and CF clinicians, and audiology professionals regarding ototoxicity monitoring. This identified gaps in the provision of ototoxicity monitoring services in the UK, especially due to the absence of nationally agreed guidelines.

This research has emphasized the significance of ototoxicity as a cause of hearing loss and the importance for audiologists to develop a leading role in establishing effective ototoxicity monitoring services to reduce or even prevent this critical disorder.

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