Vertigo and the enlarged vestibular aqueduct syndrome.

An enlarged vestibular aqueduct (EVA) is one of the most commonly identified inner ear bony malformations in children with sensorineural hearing loss of unknown cause. Most previous reports have focused on hearing loss, but individuals with EVA may also experience paroxysmal vertigo lasting minutes to hours. We report the clinical vestibular features and vestibular function testing of two children and one adult with EVA who had a history of sensorineural hearing loss and presented to our Neurotology Clinic for the evaluation of episodic vertigo. All the patients had an antecedent history of profound bilateral sensorineural hearing loss that had been present since early childhood. The onset of vertigo was delayed into adulthood in one patient. Episodes of vertigo could be triggered by minor head trauma or vigorous physical activity. Despite recurrent episodes of vertigo, vestibular function was normal or moderately impaired compared with the severe auditory deficit. Careful analysis of temporal bone CT demonstrated EVA. Associated enlargement of the membranous endolymphatic sac was evident on brain MRI. While hearing loss is a prominent symptom in patients with EVA, vestibular symptoms may cause referral to a neurologist. Although hearing loss occurs early in childhood, vestibular symptoms can be delayed into adulthood, a finding not previously reported.