Pathophysiology
In a retrospective review of 20 patients with EVA, 78.4% of ears with EVA exhibited one or more inner ear anomalies, with cochlear dysplasia being the most common (62.2%) [PMID:19775757].
Epidemiology
Initial audiometric evaluations revealed pure tone averages of 75.0 dB in the right ear and 80.4 dB in the left ear among the study cohort [PMID:17113162].
Clinical Presentation
The study included 17 patients with bilateral EVA and 3 with unilateral involvement, with an average age at diagnosis of 1.7 years [PMID:19775757].
In a retrospective review of 32 patients with EVA, 48.0% of pediatric patients and 45.5% of adult patients reported vestibular symptoms [PMID:17113162].
Diagnosis
Small field of view, thin section CT and/or MR imaging revealed cochleovestibular abnormalities in 92.5% of EVA cases reviewed [PMID:19775757].
Management
In a retrospective review, 80% of patients treated with corticosteroids showed audiometric improvement compared to 14.3% in the untreated group, with an average improvement of 17.7dB [PMID:18817986].
Four out of fourteen patients (28.6%) who underwent cochlear implantation experienced vertigo post-operatively, despite previously denying vestibular symptoms [PMID:17113162].
Prognosis & Follow-up
The study concluded that corticosteroid treatment led to better hearing outcomes compared to natural recovery in patients with EVA [PMID:18817986].
Key Recommendations
To establish definitive evidence, a prospective study with approximately 19 to 45 participants in each treatment and control group is suggested [PMID:18817986]. (Evidence: Expert opinion)
References
1 Atkin JS, Grimmer JF, Hedlund G, Park AH. Cochlear abnormalities associated with enlarged vestibular aqueduct anomaly. International journal of pediatric otorhinolaryngology 2009. link 2 Grimmer JF, Hedlund G, Park A. Steroid treatment of hearing loss in enlarged vestibular aqueduct anomaly. International journal of pediatric otorhinolaryngology 2008. link 3 Grimmer JF, Hedlund G. Vestibular symptoms in children with enlarged vestibular aqueduct anomaly. International journal of pediatric otorhinolaryngology 2007. link