29 HEARING LOSS General Discussion More than 28 million Americans have some degree of hearing impairment, and 25–40% of those aged 65 years or older are hearing impaired. The differential diagnosis of hearing loss can be simplified by determining whether the hearing loss is conductive or sensorineural. Conductive hearing loss is caused by imperfect function of the external canal, tympanic membrane, or ossicles, which are located in the outer and middle ear. Sensorineural hearing loss is caused by injury to the cochlea or auditory nerve in the inner ear. A mixed hearing loss may also occur which involves both conductive and sensorineural loss. More than 90% of hearing loss is sensorineural. Presbycusis, sensorineural loss related to aging, is the most common cause of hearing loss in the United States. This type of hearing loss is typically gradual, bilateral, and characterized by high-frequency hearing loss. The physician may be faced with a patient with sudden hearing loss. The etiology of sudden sensorineural hearing loss is not yet clear, though a variety of mechanisms such as viral infections, microcirculatory injuries, and immune-mediated disorders have been proposed. A viral infection of the cochlea is believed to be the most common cause of sudden sensorineural hearing loss. Menière’s disease is characterized by the tetrad of unilateral fluctuating hearing loss, a sensation of aural fullness, tinnitus, and vertigo. Sudden, low-frequency hearing loss is a hallmark of Menière’s disease, though higher frequencies are affected as the disease progresses. Hearing loss is typically associated with episodic and recurrent paroxysms of vertigo. The evaluation of hearing loss begins with a thorough history and physical examination followed by audiography. The goal of the audiologic evaluation is to determine the laterality, severity, and site of lesion of hearing loss. Patients with asymmetric sensorineural hearing loss require MRI of the brain with gadolinium to rule out acoustic neuroma and other cerebellopontine-angle tumors. Medications Associated with Hearing Loss Aminoglycosides Chemotherapeutics agents • Carboplatin • Cisplatin • Vincristine sulfate Diuretics • Ethacrynic acid • Furosemide Erythromycin Quinine Salicylates (especially aspirin) Vancomycin Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: ARTHRITIS AND ARTHRALGIA HAIR LOSS INFERTILITY, MALE SYNCOPE Stay updated, free articles. Join our Telegram channel Join Tags: Instant Work-ups A Clinical Guide to Medicine Aug 17, 2016 | Posted by admin in PEDIATRICS | Comments Off on HEARING LOSS Full access? Get Clinical Tree
29 HEARING LOSS General Discussion More than 28 million Americans have some degree of hearing impairment, and 25–40% of those aged 65 years or older are hearing impaired. The differential diagnosis of hearing loss can be simplified by determining whether the hearing loss is conductive or sensorineural. Conductive hearing loss is caused by imperfect function of the external canal, tympanic membrane, or ossicles, which are located in the outer and middle ear. Sensorineural hearing loss is caused by injury to the cochlea or auditory nerve in the inner ear. A mixed hearing loss may also occur which involves both conductive and sensorineural loss. More than 90% of hearing loss is sensorineural. Presbycusis, sensorineural loss related to aging, is the most common cause of hearing loss in the United States. This type of hearing loss is typically gradual, bilateral, and characterized by high-frequency hearing loss. The physician may be faced with a patient with sudden hearing loss. The etiology of sudden sensorineural hearing loss is not yet clear, though a variety of mechanisms such as viral infections, microcirculatory injuries, and immune-mediated disorders have been proposed. A viral infection of the cochlea is believed to be the most common cause of sudden sensorineural hearing loss. Menière’s disease is characterized by the tetrad of unilateral fluctuating hearing loss, a sensation of aural fullness, tinnitus, and vertigo. Sudden, low-frequency hearing loss is a hallmark of Menière’s disease, though higher frequencies are affected as the disease progresses. Hearing loss is typically associated with episodic and recurrent paroxysms of vertigo. The evaluation of hearing loss begins with a thorough history and physical examination followed by audiography. The goal of the audiologic evaluation is to determine the laterality, severity, and site of lesion of hearing loss. Patients with asymmetric sensorineural hearing loss require MRI of the brain with gadolinium to rule out acoustic neuroma and other cerebellopontine-angle tumors. Medications Associated with Hearing Loss Aminoglycosides Chemotherapeutics agents • Carboplatin • Cisplatin • Vincristine sulfate Diuretics • Ethacrynic acid • Furosemide Erythromycin Quinine Salicylates (especially aspirin) Vancomycin Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: ARTHRITIS AND ARTHRALGIA HAIR LOSS INFERTILITY, MALE SYNCOPE Stay updated, free articles. Join our Telegram channel Join Tags: Instant Work-ups A Clinical Guide to Medicine Aug 17, 2016 | Posted by admin in PEDIATRICS | Comments Off on HEARING LOSS Full access? Get Clinical Tree
