Correlations between computed tomography findings and family history in otosclerotic patients.

BACKGROUND: Otosclerosis is a heritable disease affecting the otic capsule. Its genetics have been studied since the 19th century, but several issues remain controversial. OBJECTIVE: The goals of this study were to assess the prevalence of sporadic and familial forms of otosclerosis in a population of otosclerotic patients and to compare the radiologic findings between both groups. STUDY DESIGN AND SETTING: This retrospective study was conducted in a single institution. PATIENTS: This study included 211 patients operated on for otosclerosis. MAIN OUTCOME MEASURES: Clinical data, including pure tone audiograms, were available from patients' charts. A questionnaire assessing family history of otosclerosis and deafness was mailed to the otosclerotic patients. A relative was considered otosclerotic if surgery confirmed the disease. The family history was correlated with the computed tomography results. This examination was performed before surgery in all patients. RESULTS: A family history of otosclerosis was found in 24.2% of the patients. The radiologic findings differed between patients with a sporadic form of otosclerosis and those with a familial form. The lesions were more often detectable, bilateral, and severe in the familial forms (p < 0.05). CONCLUSION: These findings lead to the assumption that fenestral radiologic otosclerosis occurs more in sporadic forms, whereas more extensive lesions on computed tomography seem to indicate the familial forms. Hereditary forms demonstrated to be familial seem to lead to more severe disease. The search for a genome locus of otosclerosis may be enlightened by these findings.