Objective: To evaluate vestibular and long-term audiometric findings in patients with Pendred syndrome.
Study design: Retrospective analysis of long-term clinical data.
Setting: University hospital department.
Patients: Three patients with Pendred syndrome caused by a mutation in the SLC26A4 gene.
Methods: Perchlorate discharge test, mutation analysis of the SLC26A4 gene, MR imaging of temporal bones, vestibular function test (in two cases) and serial audiometry. A saturation hyperbola with onset age was fitted to the audiometric threshold-on-age data using a nonlinear regression method. The residues remaining after regression were analyzed in a correlation analysis to detect significant ipsilateral or contralateral cofluctuation.
Results: All three patients had a mutation in the SLC26A4 gene and bilateral enlarged vestibular aqueduct; two of them had a positive perchlorate discharge test but in one of two siblings this test was negative. Hearing loss was significantly progressive with significant ipsilateral and contralateral cofluctuation in all evaluable cases, combined with episodes of Menière like vertigo in two cases. The episodes of vertigo are as seen in Menière disease. One case had unilateral caloric areflexia and one had bilateral vestibular hyporeflexia, proven to be progressive in a repeat examination.
Conclusions: Patients with Pendred syndrome may exhibit progressive and fluctuant hearing loss with episodes of vertigo.