耳骨硬化影響聽力

聽力出現障礙，不少人會首先聯想至耳膜穿破或聽覺神經受損，但其實聲音傳遞除了依靠耳膜及聽覺神經，還有中耳的三塊小聽骨及內耳，倘若這些地方出現問題，也會影響聽力，其中一個例子便是耳骨硬化。

耳骨硬化主要發生於小聽骨中的蹬骨，即是與內耳連接的小聽骨，或是內耳前庭迷路位置的骨膜硬化，以至它們形狀出現改變，影響它們傳遞聲音的功能，令患者聽力下降。

耳骨硬化主要受遺傳影響，多於女士身上發生，而當她們體內賀爾蒙水平出現大幅改變時，即青春期、懷孕及更年期，特別容易誘發耳骨硬化發生。病發初時並沒有明顯病徵，受影響的骨質組織會呈海綿狀，直至骨質硬化時，便會出現耳鳴、暈眩或聽力下降的情況。

由於早期病徵不明顯，所以難以在骨質尚未硬化時介入處理，當病情已進入後期時，並沒有藥物可以治療耳骨硬化，只能透過手術，置換已呈硬化的小聽骨，改善聽力障礙。但手術後患者不能舉重、潛水等令耳朵受壓的活動，否則有機會令內耳中的內淋巴液滲出，進一步破壞耳朵組織。因此，部分患者為免麻煩，寧願選擇佩戴助聽器改善聽力。

There are two types of hearing loss: conductive hearing loss and sensorineural hearing loss. Abnormalities of the hearing bones or ossicles are examples of conductive hearing loss. It affects approximately 1% of the population and is more common in female. The most common age group ranges from 15-45. Diagnosis is by audiogram which shows a conductive hearing loss and absent stapedial reflex. Treatment is either hearing aid or surgery, which involves removing the fixated hearing bone and replacing it with a prosthesis. The success rate of the procedure is about 90%. After the operation, patients are advised to avoid diving and strenuous activities that could affect middle ear pressure and stability of the prosthesis.

Sources:
http://the-sun.on.cc/cnt/news/20100708/00410_033.html