Evaluation of the thyroid in patients with hearing loss and enlarged vestibular aqueducts.

ABSTRACT: OBJECTIVE:To evaluate thyroid structure and function in patients with enlargement of the vestibular aqueduct (EVA) and sensorineural hearing loss. DESIGN:Prospective cohort survey. SETTING:National Institutes of Health Clinical Center, a federal biomedical research facility. PATIENTS:The study population comprised 80 individuals, aged 1.5 to 59 years, ascertained on the basis of EVA and sensorineural hearing loss. MAIN OUTCOME MEASURES:Associations among the number of mutant alleles of SLC26A4; volume and texture of the thyroid; percentage of iodine 123 ((123)I) discharged at 120 minutes after administration of perchlorate in the perchlorate discharge test; and peripheral venous blood levels of thyrotropin, thyroxine, free thyroxine, triiodothyronine, thyroglobulin, antithyroid peroxidase and antithyroglobulin antibodies, and thyroid-binding globulin. RESULTS:Thyroid volume is primarily genotype dependent in pediatric patients but age dependent in older patients. Individuals with 2 mutant SLC26A4 alleles discharged a significantly (P < or = .001) greater percentage of (123)I compared with those with no mutant alleles or 1 mutant allele. Thyroid function, as measured by serologic testing, is not associated with the number of mutant alleles. CONCLUSIONS:Ultrasonography with measurement of gland volume is recommended for initial assessment and follow-up surveillance of the thyroid in patients with EVA. Perchlorate discharge testing is recommended for the diagnostic evaluation of patients with EVA along with goiter, nondiagnostic SLC26A4 genotypes (zero or 1 mutant allele), or both.

SUBMITTER: Madeo AC 

PROVIDER: S-EPMC2941509 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature