Hearing loss: Difference between revisions
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==Background== | ==Background== | ||
*Sensorineural: involving the inner ear, cochlea, or auditory nerve | *Sensorineural: involving the inner ear, cochlea, or auditory nerve | ||
*Conductive: any mechanical factor blocking external sound from gaining access to the inner ear; ex: cerumen impaction, middle ear fluid, ossicular chain fixation | *Conductive: any mechanical factor blocking external sound from gaining access to the inner ear; ex: [[cerumen impaction]], middle ear fluid, ossicular chain fixation | ||
*Mixed: both sensorineural and conductive loss | *Mixed: both sensorineural and conductive loss | ||
*Should evaluate for recent medication changes, family history of hearing loss, personal history of [[trauma]], recent scuba diving or flying ([[otic barotrauma|barotrauma]]), cold water exposure, onset/progression of hearing loss, high- vs low-pitch loss, history of ear surgeries | |||
===Epidemiology=== | ===Epidemiology=== | ||
*Most common causes: presbycusis, followed by noise-induced hearing loss | *Most common causes: presbycusis (i.e. natural aging of the auditory system), followed by noise-induced hearing loss | ||
*90% of cases are due to Sensorineural hearing loss, 10% due to Conductive causes | *90% of cases are due to Sensorineural hearing loss, 10% due to Conductive causes | ||
*Most bilateral cases that present gradually are benign. Sudden onset, unilateral hearing loss is more concerning for a serious cause. | *Most bilateral cases that present gradually are benign. Sudden onset, unilateral hearing loss is more concerning for a serious cause. | ||
=== | ==Clinical Features== | ||
*Varies by etiology | |||
* | |||
==Differential Diagnosis== | |||
===Sensorineural (Inner Ear)=== | |||
*[[Sudden Sensorineural Hearing Loss (SSHL)]] | |||
*Infections: ([[Meningitis]], Viral cochleitis) | |||
*[[Barotrauma]] | |||
*[[Neck Trauma|Penetrating trauma]] | |||
*[[Meniere Disease]] | |||
*Autoimmune disease | |||
*[[Multiple Sclerosis]] | |||
*[[Stroke (Main)|Cerebrovascular ischemia]] | |||
*Tumors ([[Acoustic neuroma]], Meningioma) | |||
*Hereditary hearing loss | |||
*Congenital [[viruses|viral infections]] | |||
*Congenital malformations | |||
*Presbycusis | |||
*[[Thyrotoxicosis]] | |||
*Ototoxic drugs: [[Aminoglycosides]], [[Erythromycin]], [[Tetracycline]], chemotherapeutic agents, high-dose [[aspirin]], phosphodiesterase-5 inhibitors (e.g. [[sildenafil]], [[antimalarial]] drugs, [[Cocaine]], [[Heavy Metals]] | |||
*Otologic surgery | |||
*Noise exposure | |||
== | ===Conductive=== | ||
* | *Outer Ear | ||
* | **[[facial trauma|Trauma]] | ||
**[[Squamous cell carcinoma]] | |||
**Congenital microtia or atresia | |||
**[[Otitis Externa]] | |||
**Exostosis | |||
**Osteoma | |||
**[[Psoriasis]] | |||
**[[Cerumen impaction]] | |||
*Middle ear | |||
**Glomus tumors | |||
**[[Tympanic membrane rupture]] | |||
**Temporal bone [[trauma]] | |||
**Congenital atresia or Ossicular chain malformation | |||
**Eustachian tube dysfunction | |||
**Chronic [[Otitis media]] | |||
**[[Cholesteatoma]] | |||
**Otosclerosis | |||
==Evaluation== | |||
===Possible Testing=== | |||
====Whispered voice test==== | |||
Stand at arm’s length behind the patient and block hearing in one ear by occluding the ear canal. Whisper a phrase and ask the patient to repeat it. Test both ears. | |||
*Tone-emitting otoscope: Designed to view the ear canal and TM while emitting three different screening levels at random intervals. | *Tone-emitting otoscope: Designed to view the ear canal and TM while emitting three different screening levels at random intervals. | ||
===[[Eponyms_( | ====[[Eponyms_(T-Z)#Weber_test|Weber test]]==== | ||
*Place a vibrating tuning fork on the forehead, equidistant to both ears | |||
* | *If the patient hears the sound equally in both ears, normal hearing or symmetric hearing loss is suspected. | ||
*If sound is heard more in affected ear → consider conductive hearing loss in affected ear | |||
*If sound is heard more in unaffected ear → consider sensorineural hearing loss in affected ear | |||
===Pneumoscopy=== | ====[[Eponyms_(Q-S)#Rinne_test|Rinne test]]==== | ||
*A vibrating turning fork is placed on the mastoid bone behind the ear. When the sound is no longer heard, the fork is held near the ear canal. | |||
*If the sound is still present or louder at the ear canal, normal hearing is suspected. (i.e. Air conduction is greater than bone conduction) | |||
*If no sound is heard near the ear canal but the sound was still heard on the mastoid bone, conductive hearing loss is suspected in that ear. (i.e. bone conduction > air conduction) | |||
====Hum test==== | |||
*Hum test comparable to Weber test in diagnostic accuracy of new onset unilateral conductive hearing loss<ref>Ahmed OH et al. Validity of the Hum Test, a Simple and Reliable Alternative to the Weber Test. Ann Otol Rhinol Laryngol. 2018 Jun;127(6):402-405.</ref> | |||
*Hum test is conducted by asking the patient to hum and tell you in which ear the humming sounds louder | |||
**In sensorineural hearing loss, humming is louder in the unaffected ear | |||
**In conductive hearing loss, humming is louder in the affected ear | |||
====Pneumoscopy==== | |||
*To evaluate mobility of the TM. | *To evaluate mobility of the TM. | ||
#First, use positive pressure to force air into the EAC to push down the TM. | #First, use positive pressure to force air into the EAC to push down the TM. | ||
Line 70: | Line 84: | ||
#*Movable TM only with negative pressure = blocked Eustachian tube. | #*Movable TM only with negative pressure = blocked Eustachian tube. | ||
===Formal audiologic assessment=== | ====Formal audiologic assessment==== | ||
*Outside scope of ED evaluation | |||
*Performed by an audiologist in a soundproof environment. Air and bone conduction are both tested. | *Performed by an audiologist in a soundproof environment. Air and bone conduction are both tested. | ||
====Other tests==== | |||
===Other tests=== | |||
''Consideration for these tests should be based on history and physical'' | ''Consideration for these tests should be based on history and physical'' | ||
*Blood | *Blood glucose | ||
*CBC to evaluate for anemia or infection | *CBC to evaluate for anemia or infection | ||
*[[Thyroid]] testing | *[[Thyroid]] testing | ||
*Serologic testing for [[Syphilis]], | *Serologic testing for [[Syphilis]], [[Sjögren’s syndrome]] | ||
*CT scan for unexplained conductive hearing loss | *[[head CT|CT]] scan for unexplained conductive hearing loss | ||
*MRI for sensorineural hearing loss | *[[brain MRI|MRI]] for sensorineural hearing loss | ||
*ENT evaluation for presbycusis | *ENT evaluation for presbycusis | ||
===Diagnosis=== | |||
*Differentiate between conductive and sensorineural hearing loss | |||
==Management== | ==Management== | ||
*Based on exam findings and imaging. | *Based on exam findings and imaging. | ||
*For sudden sensorineural hearing (less than 72 hrs)<ref> Chandrasekhar, S. S., Tsai Do, B. S., Schwartz, S. R., Bontempo, L. J., Faucett, E. A., Finestone, S. A., … Monjur, T. M. (2019). Clinical Practice Guideline: Sudden Hearing Loss (Update) Executive Summary. Otolaryngology–Head and Neck Surgery, 161(2), 195–210. https://doi.org/10.1177/0194599819859883</ref>: | |||
**Every effort should be made to ensure that conductive hearing loss (eg, ruptured tympanic membrane, or congestion of the middle ear or ear canal) is not present by using a tuning fork. Tinnitus, dizziness, and vertigo are common. | |||
**Head CT not routinely necessary, but may be considered for some patients based on individual charateristics. | |||
**Routine laboratory tests not needed | |||
**ENT providers are encouraged to obtain MRI (outpatient) | |||
**'''Steroids should be given within 2 weeks of symptom onset (10- to 14-day treatment)''' | |||
**'''Do not give antivirals, thrombolytics, or vasoactive substances''' | |||
== | ==Disposition== | ||
* | *Based on diagnosis | ||
==References== | |||
<References/> | |||
[[Category:ENT]] | [[Category:ENT]] | ||
[[Category:Symptoms]] | |||
Revision as of 15:17, 11 January 2020
Background
- Sensorineural: involving the inner ear, cochlea, or auditory nerve
- Conductive: any mechanical factor blocking external sound from gaining access to the inner ear; ex: cerumen impaction, middle ear fluid, ossicular chain fixation
- Mixed: both sensorineural and conductive loss
- Should evaluate for recent medication changes, family history of hearing loss, personal history of trauma, recent scuba diving or flying (barotrauma), cold water exposure, onset/progression of hearing loss, high- vs low-pitch loss, history of ear surgeries
Epidemiology
- Most common causes: presbycusis (i.e. natural aging of the auditory system), followed by noise-induced hearing loss
- 90% of cases are due to Sensorineural hearing loss, 10% due to Conductive causes
- Most bilateral cases that present gradually are benign. Sudden onset, unilateral hearing loss is more concerning for a serious cause.
Clinical Features
- Varies by etiology
Differential Diagnosis
Sensorineural (Inner Ear)
- Sudden Sensorineural Hearing Loss (SSHL)
- Infections: (Meningitis, Viral cochleitis)
- Barotrauma
- Penetrating trauma
- Meniere Disease
- Autoimmune disease
- Multiple Sclerosis
- Cerebrovascular ischemia
- Tumors (Acoustic neuroma, Meningioma)
- Hereditary hearing loss
- Congenital viral infections
- Congenital malformations
- Presbycusis
- Thyrotoxicosis
- Ototoxic drugs: Aminoglycosides, Erythromycin, Tetracycline, chemotherapeutic agents, high-dose aspirin, phosphodiesterase-5 inhibitors (e.g. sildenafil, antimalarial drugs, Cocaine, Heavy Metals
- Otologic surgery
- Noise exposure
Conductive
- Outer Ear
- Trauma
- Squamous cell carcinoma
- Congenital microtia or atresia
- Otitis Externa
- Exostosis
- Osteoma
- Psoriasis
- Cerumen impaction
- Middle ear
- Glomus tumors
- Tympanic membrane rupture
- Temporal bone trauma
- Congenital atresia or Ossicular chain malformation
- Eustachian tube dysfunction
- Chronic Otitis media
- Cholesteatoma
- Otosclerosis
Evaluation
Possible Testing
Whispered voice test
Stand at arm’s length behind the patient and block hearing in one ear by occluding the ear canal. Whisper a phrase and ask the patient to repeat it. Test both ears.
- Tone-emitting otoscope: Designed to view the ear canal and TM while emitting three different screening levels at random intervals.
Weber test
- Place a vibrating tuning fork on the forehead, equidistant to both ears
- If the patient hears the sound equally in both ears, normal hearing or symmetric hearing loss is suspected.
- If sound is heard more in affected ear → consider conductive hearing loss in affected ear
- If sound is heard more in unaffected ear → consider sensorineural hearing loss in affected ear
Rinne test
- A vibrating turning fork is placed on the mastoid bone behind the ear. When the sound is no longer heard, the fork is held near the ear canal.
- If the sound is still present or louder at the ear canal, normal hearing is suspected. (i.e. Air conduction is greater than bone conduction)
- If no sound is heard near the ear canal but the sound was still heard on the mastoid bone, conductive hearing loss is suspected in that ear. (i.e. bone conduction > air conduction)
Hum test
- Hum test comparable to Weber test in diagnostic accuracy of new onset unilateral conductive hearing loss[1]
- Hum test is conducted by asking the patient to hum and tell you in which ear the humming sounds louder
- In sensorineural hearing loss, humming is louder in the unaffected ear
- In conductive hearing loss, humming is louder in the affected ear
Pneumoscopy
- To evaluate mobility of the TM.
- First, use positive pressure to force air into the EAC to push down the TM.
- Then, release the pressure and the negative pressure pulls the TM outwards.
- Nonmobile = fluid in middle ear, mass in middle ear, stiff/sclerotic TM.
- Hypermobile TM = ossicular chain disruption.
- Movable TM only with negative pressure = blocked Eustachian tube.
Formal audiologic assessment
- Outside scope of ED evaluation
- Performed by an audiologist in a soundproof environment. Air and bone conduction are both tested.
Other tests
Consideration for these tests should be based on history and physical
- Blood glucose
- CBC to evaluate for anemia or infection
- Thyroid testing
- Serologic testing for Syphilis, Sjögren’s syndrome
- CT scan for unexplained conductive hearing loss
- MRI for sensorineural hearing loss
- ENT evaluation for presbycusis
Diagnosis
- Differentiate between conductive and sensorineural hearing loss
Management
- Based on exam findings and imaging.
- For sudden sensorineural hearing (less than 72 hrs)[2]:
- Every effort should be made to ensure that conductive hearing loss (eg, ruptured tympanic membrane, or congestion of the middle ear or ear canal) is not present by using a tuning fork. Tinnitus, dizziness, and vertigo are common.
- Head CT not routinely necessary, but may be considered for some patients based on individual charateristics.
- Routine laboratory tests not needed
- ENT providers are encouraged to obtain MRI (outpatient)
- Steroids should be given within 2 weeks of symptom onset (10- to 14-day treatment)
- Do not give antivirals, thrombolytics, or vasoactive substances
Disposition
- Based on diagnosis
References
- ↑ Ahmed OH et al. Validity of the Hum Test, a Simple and Reliable Alternative to the Weber Test. Ann Otol Rhinol Laryngol. 2018 Jun;127(6):402-405.
- ↑ Chandrasekhar, S. S., Tsai Do, B. S., Schwartz, S. R., Bontempo, L. J., Faucett, E. A., Finestone, S. A., … Monjur, T. M. (2019). Clinical Practice Guideline: Sudden Hearing Loss (Update) Executive Summary. Otolaryngology–Head and Neck Surgery, 161(2), 195–210. https://doi.org/10.1177/0194599819859883