TAILIEUCHUNG - Chapter 030. Disorders of Smell, Taste, and Hearing (Part 9)

Disorders of the Sense of Hearing Hearing loss can result from disorders of the auricle, external auditory canal, middle ear, inner ear, or central auditory pathways (Fig. 30-4). In general, lesions in the auricle, external auditory canal, or middle ear cause conductive hearing losses, whereas lesions in the inner ear or eighth nerve cause sensorineural hearing losses. Figure 30-4 An algorithm for the approach to hearing loss. HL, hearing loss; SNHL, sensorineural hearing loss; TM, tympanic membrane; SOM, serous otitis media; AOM, acute otitis media; *, CT scan of temporal bone; t , MRI scan. . | Chapter 030. Disorders of Smell Taste and Hearing Part 9 Disorders of the Sense of Hearing Hearing loss can result from disorders of the auricle external auditory canal middle ear inner ear or central auditory pathways Fig. 30-4 . In general lesions in the auricle external auditory canal or middle ear cause conductive hearing losses whereas lesions in the inner ear or eighth nerve cause sensorineural hearing losses. Figure 30-4 An algorithm for the approach to hearing loss. HL hearing loss SNHL sensorineural hearing loss TM tympanic membrane SOM serous otitis media AOM acute otitis media CT scan of temporal bone t MRI scan. Conductive Hearing Loss This results from obstruction of the external auditory canal by cerumen debris and foreign bodies swelling of the lining of the canal atresia or neoplasms of the canal perforations of the tympanic membrane disruption of the ossicular chain as occurs with necrosis of the long process of the incus in trauma or infection otosclerosis or fluid scarring or neoplasms in the middle ear. Rarely inner-ear malformations may present as conductive hearing loss beginning in adulthood. Cholesteatoma stratified squamous epithelium in the middle ear or mastoid occurs frequently in adults. This is a benign slowly growing lesion that destroys bone and normal ear tissue. Theories of pathogenesis include traumatic implantation and invasion immigration and invasion through a perforation and metaplasia following chronic infection and irritation. On examination there is often a perforation of the tympanic membrane filled with cheesy white squamous debris. A chronically draining ear that fails to respond to appropriate antibiotic therapy should raise suspicion of a cholesteatoma. Conductive hearing loss secondary to ossicular erosion is common. Surgery is required to remove this destructive process. Conductive hearing loss with a normal ear canal and intact tympanic membrane suggests ossicular pathology. Fixation of the stapes from otosclerosis

• Y học thường thức
• Disorders of Smell
• Taste
• Hearing
• bệnh học và điều trị
• bài giảng bệnh học
• tài liệu học ngành y
• Harrisons Internal Medicine
• Taste disorders
• Smell and taste disorders
• Non neurodegenerative disorders
• Neurodegenerative chemosensory disorders
• Chemosensory disorders
• Medicolegal aspects
• Physiology of olfaction
• Anatomy and physiology of gustation
• Measurement of gustation
• Measurement of olfaction
• medical books
• pharmacology
• epidemiologic
• Obstetrics
• anatomy
• Preventing Morbidity
• Multidisciplinary Care