The complex interplay of EVA and adolescent-onset hearing loss: a case report

Abstract Background Enlarged Vestibular Aqueduct (EVA) presents diagnostic challenges owing to varied clinical manifestations and significant variation in hearing loss (HL) progression, which makes it difficult for clinicians to provide timely advice on HL surveillance, surgical interventions, and lifestyle modifications. EVA is often identified incidentally after head trauma or through unrelated symptoms. Aim This case report details an uncommon presentation of EVA in an adolescent, drawing attention to its diverse clinical expression and stressing the need for reliable prognostic tools to guide clinical decision-making and patient support. An adolescent with atypical EVA highlights clinical variability and emphasizes the importance of developing prognostic criteria for better management and counseling. Case presentation A 17-year-old male patient was seen in the Hearing and Balance Clinic at Dubai Hospital in August 2024 with a chief complaint of a constant left ear tinnitus of a few months’ duration. The patient was asymptomatic and did not present with any vestibular symptoms (such as dizziness or vertigo) or systemic comorbidities. On initial examination and audiological assessment, Pure-tone audiometry (PTA) revealed normal right ear thresholds up to 4 kHz, with moderate, sloping sensorineural hearing loss (SNHL) at higher frequencies. The left ear had normal thresholds up to 1 kHz, with moderate to severe SNHL at higher frequencies. Bilateral Type A tympanograms with asymmetrical acoustic reflexes matched the PTA findings. Subsequent evaluations showed stable right ear thresholds but progressive moderate to severe SNHL in the left ear, possibly linked to noise exposure during national service. Despite a 15-day tapered corticosteroid regimen, a limited improvement was noted at low frequencies during follow-up. MRI and CT scans showed significant dilatation of the left vestibular aqueduct and enlargement of the endolymphatic sac. This case suggests that noise exposure may act as an aggravating factor in EVA-associated asymmetric SNHL. Conclusion This case report illustrates an atypical presentation of EVA, which was incidentally discovered and suggested as a potential cause of progressive SNHL. EVA should be included in the differential diagnoses of unilateral SNHL. EVA's clinical variability supports its consideration as a spectrum disorder, emphasizing the need for standardized prognostic criteria to predict the progression course of hearing loss, improve management, and counseling.