Blast-induced hearing loss / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The incidence of blast injury has increased recently. As the ear is the organ most sensitive to blast overpressure, the most frequent injuries seen after blast exposure are those affecting the ear. Blast overpressure affecting the ear results in sensorineural hearing loss, which is untreatable and often associated with a decline in the quality of life. Here, we review recent cases of blast-induced hearing dysfunction. The tympanic membrane is particularly sensitive to blast pressure waves, since such waves exert forces mainly at air-tissue interfaces within the body. However, treatment of tympanic membrane perforation caused by blast exposure is more difficult than that caused by other etiologies. Sensorineural hearing dysfunction after blast exposure is caused mainly by stereociliary bundle disruption on the outer hair cells. Also, a reduction in the numbers of synaptic ribbons in the inner hair cells and spiral ganglion cells is associated with hidden hearing loss, which is strongly associated with tinnitus or hyperacusis.

Objective comparison between perforation and hearing loss / Comparação objetiva entre perfuração timpânica e perda auditiva

INTRODUCTION: There appears to be no relationship between the size of tympanic perforations and hearing loss. Some studies in the literature have assessed this connection, with conflicting data and without proper methodology, especially concerning the measurement of the size of the perforation, which was performed in a subjective manner. OBJECTIVE: To evaluate the size of tympanic perforations and to relate them to hearing loss in four different sound frequencies through the use of an objective method. METHODS: Transversal retrospective study. The present study evaluated 187 perforations through digital imaging, calculated the percentages of the tympanic membrane that was perforated using ImageScope software version 11.1.2.760 and correlated perforations size with hearing loss at four frequencies. RESULTS: Data were statistically analyzed using Pearson's correlation test. CONCLUSION: There was no significant relationship between the size of tympanic perforations and hearing loss in the four analyzed frequencies. .

INTRODUÇÃO: Parece não haver relação entre o tamanho das perfurações timpânicas e a perda auditiva. Alguns trabalhos na literatura estudaram esta relação, com dados conflitantes e sem uso adequado da metodologia empregada, principalmente quanto à medição do tamanho da perfuração que se faz de modo subjetivo. OBJETIVO: Analisar através de um método objetivo o tamanho dessas perfurações e relacioná-las com perdas auditivas em quatro frequências sonoras. MÉTODO: Estudo retrospectivo de corte transversal. Foram avaliadas 187 perfurações timpânicas através de digitalização de imagem, medidas porcentualmente com o uso do software ImageScope Version 11.1.2.760 e correlacionadas com os limiares auditivos em quatro frequências. RESULTADOS: Os dados foram avaliados estatisticamente pelo teste de correlação de Pearson, que não demonstrou correlação entre o tamanho da perfuração timpânica e o grau de perda auditiva. CONCLUSÃO: Não há relação significativa entre o tamanho das perfurações timpânicas e as quatro frequências estudadas. .

Fístula perilinfática traumática: entidad otorrinolaringológica poco frecuente / Traumatic perilymphatic fistula: a rare otorhinolaryngological entity

La fístula perilinfática corresponde a una patología infrecuente en la práctica otorrinolaringológica diaria. Esta puede tener un origen congénito, de aparición espontánea o más frecuentemente postraumática, presentando habitualmente la triada clínica de hipoacusia, tinnitus y vértigo. A continuación se presenta el caso clínico de una paciente de 50 años atendida en el Servicio de Otorrinolaringología del Hospital Clínico de la Universidad de Chile, ingresada por un cuadro con clínica compatible, de inicio súbito luego de una perforación timpánica traumática autoinferida.

Perilymphatic fistula is an infrequent pathology in standard otorhinolaryngological practice. Fistulas of this sort may be of congenital, spontaneous or, more frequently post traumatic origin, normally presenting with the clinical triad of hearing loss, tinnitus and vertigo. The case of a 50 year old patient presenting with clinically compatible symptoms of sudden appearance after a self-infringed traumatic tympanic perforation is discussed.

Frequency dependence of hearing loss with perforations.

This cross-sectional study was conducted in different sizes of pars tensa perforation in patients with chronic suppurative otitis media (CSOM) tubo-tympanic type undergoing myringoplasty. A total of 50 patients were recruited from the outpatient Department of Otorhinolaryngology - Head and Neck Surgery in TU Teaching Hospital from June 2003 to May 2004. Cases of CSOM tubo-tympanic type with dry central perforation, conductive type of hearing loss were subjected to myringoplasty. Preoperative audiometric evaluations were done. While operating under microscope diameter of perforations were measured and perforations were grouped according to the size. This study showed that the hearing loss was found to be more at lower frequencies and less as the frequencies increased. Hearing loss is more marked at lower frequencies as compared to higher frequencies, irrespective any size or location of perforation of pars tensa.

Perfuração timpânica: causas e o que fazer / Tympanic perforation: causes and what to make

Os autores fazem uma revisão bibliográfica sobre as principais causas de perfuração da membrana timpânica, sua sintomatologia, complicações relacionadas e condutas a serem adotadas na prática médica.

Size of typmanic membrane perforation and hearing loss.

This prospective study was done to assess the level of preoperative hearing impairment in different sizes of pars tensa perforation in patients with chronic suppurative otitis media (CSOM) tubo-tympanic type undergoing myringoplasty. A total of 50 patients were recruited from the outpatient Department of Otorhinolaryngology - Head and Neck Surgery from June 2003 to May 2004. Cases of CSOM tubo-tympanic type with dry central perforation, conductive type of hearing loss were subjected to myringoplasty. Preoperative audiometric evaluations were done. While operating under microscope diameter of perforations were measured and perforations were grouped according to the size. It was observed that greater hearing loss was reported in group D perforation (44 dB), where as in group A, it was 31 dBHL. The average hearing loss at 500 Hz was 46.40 dB, at 1000 Hz was 30.90 dB and at 2000 Hz it was 31.9 dB. This shows that the hearing loss is more at lower frequencies and less as the frequencies increase. This study shows that as the size of perforation is increased, the hearing loss also increases. The hearing loss is more marked at lower frequencies as compared to higher frequencies.