What are the types and causes of hearing loss?

2. The cause of sensorineural hearing loss

目前,已知有很多基因都与非综合征性耳聋有关,其中的一个或几个基因存在突变,或一个基因中的不同位点存在突变,都会引起耳聋。但在不同种族,甚至同一种族不同地区的人群中,耳聋基因及其突变位点不尽相同。我国的相关研究显示GJB2、SLC26A4、线粒体基因(A1555G和C1494T突变)是导致中国大部分遗传性耳聋发生的三个最为常见的基因,对这少数几个基因进行遗传学检测可以明确耳聋人群中40%的遗传学病因,结合家族史分析和查体可以诊断95%以上的遗传性耳聋。耳聋基因的筛查和检测为先天性感音神经性耳聋的预防,减少其发病率提供了可能性。

(10) Meniere’s disease Meniere’s disease is an unexplained inner ear disease with membrane labyrinth hydrops as the main pathological feature.Its course is variable, with paroxysmal dizziness, fluctuating deafness and tinnitus as its main symptoms.The etiology of Meniere’s disease is unknown, and may be related to congenital inner ear abnormalities, autonomic dysfunction, viral infection, allergies, endocrine disorders, salt and water metabolism disorders, etc.At present, it is generally believed that the obstruction of endolymphatic drainage or malabsorption is the main cause of disease, such as endolymphatic stenosis or blockage; autonomic dysfunction can cause inner ear small blood vessels spasm, leading to labyrinth microcirculation disorders, tissue hypoxia, and endolymph biochemical properties Change, the osmotic pressure increases, causing water in the labyrinth of the membrane.The pathological change of this disease is membranous labyrinth hydrops, mainly involving the cochlear duct and balloon.Compression stimulates the cochlea to produce cochlear symptoms such as tinnitus and deafness, while compression stimulates the vestibular terminal organs to produce vestibular symptoms such as dizziness.The typical symptoms are paroxysmal dizziness, fluctuating deafness, tinnitus, and ear fullness.

There are lesions in the sound transmission and sensory structures at the same time.Such as long-term chronic suppurative otitis media, advanced otosclerosis and so on.

(2) Cortical deafness Cortical deafness is difficult to distinguish the distance and nature of sounds. Sometimes, although the general hearing is not impaired, the aesthetic ability for language is reduced.Because one side of the cochlear nerve nucleus fibers project to both sides of the auditory cortex, one side of the auditory cortex is damaged or one side of the conduction pathway is damaged, resulting in one or both sides of hearing loss.

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