Tomografia computadorizada no diagnóstico da otosclerose retrofenestral

Abstract

Obj etivo:Identificar os principais achados tomográficos da otosclerose retrofenestral. Método: Estudo prospectivo multicêntrico com tomografia computadorizada (TC) de ossos temporais em 54 pacientes com diagnóstico clínico e cirúr-gico de otosclerose. Foi realizada uma análise tomográfica, em que foi avaliada a utilidade da TC no diagnóstico radiológico da otosclerose retrofenestral, sendo verificados os principais sítios de lesões dessa doença. Foram incluídos neste estudo 22 pacientes submetidos à TC de ossos temporais para investigação de outras afecções otológicas, que constituíram o grupo controle. Resultados: Os achados tomográficos foram bilaterais na maioria dos casos e o foco retrofenestral mais prevalente foi o foco pericoclear. Conclusões: A TC monstrou-se útil na identificação dos focos retrofenestrais. A evidência tomográfica desses focos juntamente com o envolvimento endosteal da cóclea podem sugerir uma maior atividade da doença. Andy de Aim:To identify the main tomographic findings of retrofenestral otosclerosis. Methods: A prospective and multicentric study using computed tomography (CT) of the temporal bone in 54 patients with a clinical and surgical diagnosis of otosclerosis. A tomographic analysis has been performed to evaluate the utility of CT scans in diagnosing retrofenestral otosclerosis, verifying the sites of predilection for otosclerotic lesions. In this study, 22 patients undergone CT scans of temporal bones have been included in order to investigate other otologic diseases and have constituted the control group. Results: The tomographic findings were mostly bilateral and the retrofenestral focus more prevalent was the pericochlear focus. Conclusions: The CT scan was useful in the identification of the retrofenestral focuses. The evidence of this focuses and the presence of the endosteal involvement of the cochlea can suggest a higher activity of the disease.Palavras-chave: otosclerose, tomografia computadorizada por Rx, cóclea.

A mass-spring model of the auditory system in otosclerosis

“…The discrete mass-spring model of the ear contributed to an enhanced understanding of how the structures affected by otosclerosis influence hearing, and how they relate to the different grades of the disease. When investigating the altered parameters in otosclerosis, it was possible to predict both quantitatively and qualitatively, based on the discrete mass-spring model, the influence of stapedial annular ligament stiffness (Dai et al, 2009;Feng and Gan, 2004;Huber et al, 2003;Min et al, 2010) at the early stages and the influence of increased stapedial mass (Beales, 1987;Brookler, 2008;Frost, 1962;Hungria, 1988;Iyer and Gristwood, 1984;Miller and Schein et al, 2005;Min et al, 2010;Vicente et al, 2004) at the advanced stages, thereby corroborating the qualitative data already reported in the literature.…”

“…In our discrete mass-spring model of the auditory system, simulating increased stapedial mass resulted in reduced displacement of the stapes only at the higher frequencies (above 2000 Hz), as expected for the late stages of the disease. The overgrowth of bony tissue is probably associated with the more advanced stages of the disease, as reported qualitatively in the literature (Frost, 1962;Hungria, 1988;Miller and Schein, 2005;Min et al, 2010;Palacius and Valvassori, 2001;Vicente et al, 2004). Speech audiometry shows a marked decline in speech discrimination (Hungria, 1988); consequently, the individual complains of difficulties in understanding what is spoken, even with great intensity, particularly in the case of losses around 90 dB (Albernaz, 2008).…”

“…In addition to increased stapedial annular ligament stiffness, abnormal bony tissue formation is known to occur in otosclerosis (Brookler, 2008;Frost, 1962;Hungria, 1988;Miller and Schein, 2005;Min et al, 2010;Vicente et al, 2004). It is also known that the second most commonly affected site is the oval window area and the stapes footplate (Beales, 1987).…”

“…The second most frequently involved site is the area of the oval window and the stapedial footplate (Beales, 1987). The characteristic changes of otosclerosis in the auditory system are increased stiffness of the stapedial annular ligament (Dai et al, 2009;Feng and Gan, 2004;Huber et al, 2003;Min et al, 2010) and abnormal bone growth (Brookler, 2008;Frost, 1962;Hungria, 1988;Miller and Schein, 2005;Min et al, 2010;Vicente et al, 2004).…”