Use of laboratory evaluation and radiologic imaging in the diagnostic evaluation of children with sensorineural hearing loss.

Objective: Laboratory testing and radiologic imaging are commonly used to delineate syndromic from nonsyndromic sensorineural HL (SNHL). The aim of this study was to examine the yield of laboratory tests and radiologic imaging commonly used in the diagnostic evaluation of SNHL in children.

Study Design: Retrospective analysis of 114 (54 female, 60 male) consecutively investigated children with SNHL between 1998 and 2000 at a tertiary-care university hospital.

Methods: Results of routine laboratory testing to assess autoimmunity, blood dyscrasias, endocrine abnormalities, renal function, infection, and cardiac testing were reviewed. Results of radiologic evaluation were also reviewed. In general, computed tomography (CT) was obtained in patients with symmetric SNHL, whereas magnetic resonance imaging (MRI) with or without CT was obtained in asymmetric SNHL.

Results: Laboratory evaluation of the blood did not yield the etiology of SNHL in any patient. Blood tests for autoimmune disease were often positive but did not correlate with clinical disease. Nonspecific elevation of erythrocyte sedimentation rate (ESR) and antinuclear antibody (ANA) was present in 22% of cases. An abnormal electrocardiogram with a prolonged QT interval resulted in the diagnosis of Jervall and Lange-Nielsen syndrome. In the 97 patients who underwent radiologic studies, abnormalities were present in 38 of 97 studies (39%). Isolated inner ear malformations were twice as common as multiple abnormalities with large vestibular aqueducts as the most common isolated finding.

Conclusion: In the evaluation of children with unexplained SNHL, routine laboratory evaluation should be reconsidered given its low diagnostic yield. However, radiologic abnormalities of the inner ear are common. Identification of inner ear malformations has direct impact on management of these children, suggesting that all children should undergo radiologic imaging as an integral component of evaluation of SNHL.