Bilateral Sensorineural Hearing Loss as a Manifestation of Toxic Encephalitis: A Comprehensive Audiological and Neurological Case Report
Abstract
Background and Aim: Toxic encephalitis, a rare form of neuroinflammation induced by toxic agents, can lead to multifaceted neurological dysfunction, including auditory impairment. Sensorineural hearing loss (SNHL), a reduction in hearing sensitivity due to inner ear or auditory nerve damage, is an uncommon but clinically significant manifestation in such cases. This study aimed to present a comprehensive audiological and neurological evaluation of a patient with toxic encephalitis to highlight the auditory consequences and emphasize the importance of early detection and intervention.
Case presentation: We report a 44-year-old woman with progressive bilateral SNHL over one year and vertigo. Neurological examination showed cerebellar dysfunction, and Magnetic resonance imaging revealed multiple acute infarcts with basal meningeal enhancement and vasculitic changes suggestive of toxin-induced neuroinflammatory injury. Occupational history confirmed prolonged exposure to industrial solvents, a recognized neurotoxic factor. Audiological testing demonstrated bilateral moderate SNHL with absent otoacoustic emissions and abnormal auditory brainstem responses, supporting the diagnosis of toxic encephalopathy with encephalitic features.
Conclusion: This study highlights the significant impact of toxic encephalitis on auditory pathways, revealing vulnerabilities in cochlear and brainstem structures. By integrating behavioral, physiological, and electrophysiological evaluations, it provides insights into hearing loss associated with the condition. Early diagnosis and intervention are crucial to improving outcomes, and further research is needed to explore the mechanisms linking toxic encephalitis features and auditory dysfunction.
2. Kim Y, Kim JW. Toxic encephalopathy. Safety and Health at Work. 2012; 3(4):243–56. [DOI:10.5491/SHAW.2012.3.4.243]
3. GBD 2016 Neurology Collaborators. Global, regional, and national burden of neurological disorders, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2019;18(5):459-80. [DOI:10.1016/S1474-4422(18)30499-X]
4. Kakkar M, Rogawski ET, Abbas SS, Chaturvedi S, Dhole TN, Hossain SS, et al. Acute encephalitis syndrome surveillance, Kushinagar district, Uttar Pradesh, India, 2011-2012. Emerg Infect Dis. 2013;19(9):1361-7. [DOI:10.3201/eid1909.121855]
5. Ren, W., Xu, S., & Ren, J. (2023). The effects of co-exposure to noise and solvents on hearing: A systematic review and meta-analysis. Safety, 9(4), 71. https://doi.org/10.3390/safety9040071
6. Sørensen, A. R., Kristiansen, J., Juhl, P. M., Garde, A. H., & Poulsen, O. M. (2007). Auditory tests as a tool in the diagnosis of solvent-induced encephalopathy. Noise & Health, 9(36), 51–58. https://doi.org/10.4103/1463-1741.34701
7. Muthaiah VPK, Chen GD, Ding D, Salvi R, Roth JA. Effect of manganese and manganese plus noise on auditory function and cochlear structures. Neurotoxicology. 2016;55:65-73. [DOI:10.1016/j.neuro.2016.05.014]
8. Discalzi, G. L., Capellaro, F., Civra, A., & Cadario, L. (1993). Auditory brainstem evoked response (BAER) in workers exposed to neurotoxic substances. International Journal of Psychophysiology, 15(3), 205–209. https://doi.org/10.1016/0167-8760(93)90080-9
9. Fuente A, McPherson B. Central auditory processing effects induced by solvent exposure. Int J Occup Med Environ Health. 2007;20(3):271-9. [DOI:10.2478/v10001-007-0030-4]
10. van Valen E, Wekking E, van Hout M, van der Laan G, Hageman G, van Dijk F, et al. Chronic solvent-induced encephalopathy: course and prognostic factors of neuropsychological functioning. Int Arch Occup Environ Health. 2018;91(7):843-58. [DOI:10.1007/s00420-018-1328-1]
11. Di Stadio A, De Luca P, Koohi N, Kaski D, Ralli M, Giesemann A,et al. Neuroinflammatory disorders of the brain and inner ear: a systematic review of auditory function in patients with migraine, multiple sclerosis, and neurodegeneration to support the idea of an innovative 'window of discovery'. Front Neurol. 2023;14:1204132. [DOI:10.3389/fneur.2023.1204132]
12. Choi YH, Kim K. Noise-induced hearing loss in Korean workers: co-exposure to organic solvents and heavy metals in nationwide industries. PLoS One. 2014;9(5):e97538. [DOI:10.1371/journal.pone.0097538]
13. Sliwinska-Kowalska M, Zamyslowska-Szmytke E, Szymczak W, Kotylo P, Fiszer M, Wesolowski W, et al. Effects of coexposure to noise and mixture of organic solvents on hearing in dockyard workers. J Occup Environ Med. 2004;46(1):30-8. [DOI:10.1097/01.jom.0000105912.29242.5b]
14. Gunawan PI, Polanunu MR. Correlation between Hearing Loss with Acute Encephalitis Syndrome in Indonesian Children. J Liaquat Univ Med Health Sci. 2023;22(03):164-8. [DOI:10.22442/jlumhs.2023.00973]
15. Rivers D, Gunnell S, Clark J, Lenehan R, Phenis R, Shan Y, et al. Clinical Reasoning: A 66-Year-Old Woman with Progressive Encephalopathy and Bilateral Hearing Loss. Neurology. 2023;100(5):254-258. [DOI:10.1212/WNL.0000000000201536]
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| Issue | Articles in Press | |
| Section | Case Report(s) | |
| Keywords | ||
| Toxic encephalitis audiological assessment sensorineural hearing loss early identification early intervention | ||
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