Abstract Introduction Cholesteatoma is a disease with significant clinical impact but is incompletely understood. The challenge of performing studies with long-term follow-up in humans is a factor that has restricted the advance of knowledge in this field. Thus, the use of animal models is highly pertinent, and the Mongolian gerbil model has emerged as one of the most useful. Objective The present study aims to evaluate, through serial otoendoscopies, the development and characteristics of pars flaccida retraction pocket and cholesteatoma in Mongolian gerbils after obliteration of the eustachian tube and compare it with the control group. Methods Forty Mongolian gerbils were divided into two groups of 20 animals each. In the intervention group, the animals were followed with serial otoendoscopies after eustachian tube obliteration. In the control group, the animals were only followed through serial otoendoscopies. Results At the end of the 16-week follow-up, cholesteatoma was present in 13 of 38 (34.2%) ears in the intervention group, and in 7 of 34 (20.6%) in the control group (p = 0.197). When we considered cholesteatoma and its potential precursor, pars flaccida retraction pocket, in a combined way, we verified it in 23 of 38 (60.8%) in the intervention group and in 11 of 34 (32.3%) in the control group (p = 0.016). Conclusions Over the 16 weeks of follow-up, serial otoendoscopies enabled us to evaluate the formation and development of pars flaccida retraction pockets and cholesteatomas in Mongolian gerbils and proved to be an excellent diagnostic tool.

Com o aumento da expectativa de vida no Brasil e no mundo, crescem as preocupações com as doenças mais prevalentes entre os idosos, dentre elas as doenças neurodegenerativas (DN) como a doença de Alzheimer (DA) e a doença de Parkinson (DP). Sabe-se que os depósitos proteicos relacionados com o desenvolvimento destas doenças podem preceder a fase sintomática em anos. A proteína tau é de particular interesse, uma vez que parece ser encontrada no tronco encefálico e bulbo olfatório muito antes de atingir o córtex límbico, quando ocorrem os primeiros sintomas. Dos 14 encéfalos coletados neste estudo, a proteína tau foi encontrada, no tronco encefálico, em 10 (71,42%) e no bulbo olfatório em 3 de 11. Dos 7 indivíduos que tiveram diagnóstico final de DA, todos apresentavam depósitos de tau em alguma região do tronco encefálico. Nossos dados estão de acordo com a literatura mais recente, que tem confirmado a presença de proteína tau no tronco encefálico e bulbo olfatório nos estágios mais precoces da DA.

With the increase in life expectancy in Brazil, concerns have grown about the most prevalent diseases in elderly people. Among these diseases are neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases. Protein deposits related to the development of these diseases can pre-date the symptomatic phases by years. The tau protein is particularly interesting: it might be found in the brainstem and olfactory bulb long before it reaches the limbic cortex, at which point symptoms occur. Of the 14 brains collected in this study, the tau protein was found in the brainstems of 10 (71.42%) and in olfactory bulbs of 3 out 11. Of the 7 individuals who had a final diagnosis of Alzheimer’s disease (AD), 6 presented tau deposits in some region of the brainstem. Our data support the idea of the presence of tau protein in the brainstem and olfactory bulb in the earliest stages of AD.