Unravelling Hearing Loss in Toxic Encephalitis: A Detailed Single Case Analysis

Introduction Encephalitis is a rare but severe brain inflammation that often presents with neuropsychological dysfunction and may co-occur with meningitis. Sensorineural hearing loss (SNHL) is a significant complication of toxic encephalitis, caused by damage to auditory pathways. This case study explores the link between toxic encephalitis and auditory dysfunction, emphasizing the importance of early detection through diagnostic evaluations to prevent long-term complications. Case Report A 44-year-old woman presented with a one-year history of progressive bilateral hearing loss and 20 days of persistent giddiness. ENT examination revealed that the right ear was normal, while the left ear showed a retracted tympanic membrane. Neurological and radiological evaluations uncovered vasculitic changes, infarcts, and cerebellar dysfunction, leading to a diagnosis of toxic encephalitis. Methods Audiological assessments included otoscopy, pure-tone and speech audiometry, tympanometry, acoustic reflex testing, otoacoustic emissions (DPOAEs and TEOAEs), and auditory brainstem response (ABR) testing to evaluate auditory thresholds and identify cochlear and brainstem dysfunction . Results The patient exhibited bilateral moderate SNHL with normal middle ear function. Reflexometry revealed absent or elevated acoustic reflexes, while otoacoustic emissions confirmed outer hair cell dysfunction. ABR testing demonstrated absent wave V responses below 70 dBnHL, consistent with moderate SNHL. Follow-up evaluations showed stable auditory thresholds. 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 and auditory dysfunction.