Ver el código de «Hearing loss»

==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 ([[otic barotrauma|barotrauma]]), cold water exposure, onset/progression of hearing loss, high- vs low-pitch loss, history of ear surgeries

===Epidemiology===
*Most common causes: presbycusis, 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]]
*[[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==
*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. 

===[[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

===[[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.
#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]]
*[[head CT|CT]] scan for unexplained conductive hearing loss
*[[brain MRI|MRI]] for sensorineural hearing loss
*ENT evaluation for presbycusis

==Management==
*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:Symptoms]]