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Unilateral Sensorineural Hearing Loss


• What dilemmas?
– Increasing number and complexity of tests
– Increasing costs of medical care
– What do tests results mean?
– At what point does cost of testing outweigh value of “rule out” diagnosis?
– How far do we go to diagnose etiology?
• Diagnosis of the following:
– Unilateral Childhood SNHL of unknown duration
– Sudden sensorineural hearing loss
– Unilateral inner ear complaints

Unilateral Childhood SNHL
• Unilateral SNHL in moderate to profound range correlates with:
– Poor academic performance
– Increased chance of repeating a grade
– Behavioral problems
Intervention prior to 6 months results in advantages in communication

• Universal infant screening has led to earlier diagnosis
• Congenital hearing loss may be delayed
• Joint Committee on Infant Hearing guidelines for persistent periodic screening:
– Child with family history of early onset SNHL
– Prenatal infection that may lead to SNHL
– Neurofibromatosis II
– Persistent pulmonary hypertension 

• Epidemiology
– Average age of diagnosis unilateral SNHL is 8.7 yo.
– Bilateral SNHL grater than 50dB, 1-2/1000
– Unilateral SNHL greater than 50 dB, 3/1000
– Genetic cause in 50% of individuals

• Initial referral because of failed audiogram, parental concerns.
• Confirmed with audiogram, OAE, ABR
• In younger children, otolaryngologist must screen for conductive etiology

• Differential diagnosis
– Syndrome with hearing loss
– Other genetic cause
– Meningitis
– Intrauterine infection
– Trauma to cochlea, vestibule, VIII
– Exposure to ototoxic drug
– Prematurity
– Autoimmune disease
– Hyperbilirubinemia
– Neurofibromatosis type II
– Anoxic Brain injury
– Mumps
– Neurodegenerative disorder
– Malignant infiltration
– Ischemic insult of cochlea
– Cochlear hydrops

• Genetic basis in 50%
– Over 200 syndromes include deafness or hearing impairment
– Identification of syndrome allows efficient screening for other anomalies

• Usher syndrome
– Autosomal recessive disorder
– Retinitis pigmentosa and SNHL
– Early intervention for future visual and auditory impairment
– Bilateral cochlear implant should be considered

Waardenburg syndrome
– White forelock
– Multicolored iries
– Dystropia canthorum
– hypertelorism

• Jervell and Lange-Nielsen
– Autosomal dominant
– Seen in 1.6 to 6 per million
– Prolonged QT interval and increased risk of sudden death
– First degree relatives need screening with EKG

• Neurofibromatosis Type II
– Autosomal dominant
– Bilateral acoustic neuromas
– Meningiomas
– Spinal schwannomas
– Posterior capsular lens opacities

• Alports syndrome
– Autosomal dominant or recessive, or x-linked
– Slowly progressive bilateral SNHL, can be asymmetrical
– Progressive renal failure
– Persistent microscopic hematuria
– Episodic gross hematuria precipitated by URI

• Branchio-oto-renal syndrome
– 1/40,000 live births
– 60% with branchial cleft cysts
– 20% with pure SNHL, majority mixed
– Shared antigen between the stria vascuularis and glomeruli

• Noonan’s syndrome
– 1/2500 live births
– Webbed neck
– Pinna abnormalities
– Short stature
– 10-15% with SNHL

• CHARGE Syndrome
– Coloboma
– Heart Defects
– Atresia choanae
– Retarded growth
– Genital hypoplasia
– Ear abnormalities and deafness
– Associated with Mondini malformation

• Fechner’s syndrome
– High frequency SNHL
– Proteinuria
– Macrothrombocytopenia
– Ocular disease
– Extremely rare

• Pendred syndrome
– Autosomal recessive
– Congenital SNHL
– Goiter
– Hypothyroidism (varies)
– Abnormal perchlorate discharge test
– Associated with Mondini and Large Vestibular aqueduct

• Other causes
– TORCHS (Toxoplasmosis, Others, Rubella, Cytomegalovirus, Herpes simplex, Syphilis)
– Meningitis
– Ototoxic drug exposure
– Maternal drug alcohol use
– Maternal use of teratogenic drug (thalidomide)

Diagnostic Testing
• CBC with Differential
• Platelet studies
• BUN, Creatinine, Urinalysis
• Serum glucose
• Thyroid function tests, Perchlorate test
• GJB2 (Connexin 26)

• CBC with differential
– Used to screen for leukemia or lymphoma
– Hearing loss due to hyperviscosity or temporal bone infiltration
– 1 case of leukemia with hearing loss as initial manifestation in literature
– Low yield

• Platelet studies
– Drawn to exclude Fechner syndrome
– Patients with family history, ocular disease, history of diagnosed proteinuria should be screened
– Test is low yield

– Drawn to screen for autoimmune disorders, Lupus, Cogan's, juvenile rheumatoid arthritis
– Test nonspecific
– Positive RF is 0.7% sensitive in detecting juvenile RA
– Testing without history of joint pain or other signs of systemic autoimmune disorders is low yield

• BUN, Creatinine, Urinalysis
– Used to screen for concurrent kidney disease such as Alport’s disease
– Should be drawn with history of gross hematuria, family history of kidney disease, family history of slowly progressive hearing loss
– Routine screening is low yield

• Serum glucose
– Used to screen for Alston syndrome (Impaired glucose tolerance, retinal degeneration, neurosensory deafness, acanthosis nigricans, hepatic dysfunction)
– Only 50 cases reported since 1959
– Very low yield

• Thyroid function testing
– Drawn to screen for hypothyroidism and Pendred syndrome
– Hearing loss as a sole symptom of hypothyroidism is very rare
– Pendred syndrome not always associated with hypothyroidism. Perchlorate testing test of choice
– Testing highest yield in children with goiter, signs of hypothyroidism, large vestibular aqueduct or Mondini malformation

– Drawn to look for syphilis.
– Hearing loss with tertiary syphilis usually associated with other manifestations of the disease, but can be sole manifestation
– History of maternal syphilis exposure, signs of tertiary syphilis make testing higher yield
– Testing low yield

– Used to screen for prolonged QT interval in Jervall and Lange-Nielson syndrome
– Test highest yield with family history of childhood death or syncope
– Low yield

• GJB2 gene (Connexin 26)
– Responsible for as much as 50% of autosomal recessive nonsyndromic hearing loss
– Use most important in genetic counseling for parents of hearing impaired children
– Homozygous children have a 25% chance of having siblings with hearing loss. Negative or heterozygous results gives siblings 14% chance

• CT and MRI
– Used to scan for inner ear malformations
– Mondini malformation associated with perilymphatic fistulas and recurrent meningitis
– Large vestibular aqueduct associated with hearing loss as a result of minor head trauma
– MRI used for screening for acoustic neuroma in children with neurofibromatosis type II
Mafong et al, Laryngoscope 2002
• Retrospective chart review 114 children with SNHL
• ANA, RF, ESR, CBC, Platelet studies, BUN, Creatinine, Urinalysis, Serum Glucose, FT4, TSH, T3, FTA-ABS, RPR, EKG, CT scans reviewed
• EKG positive in 1 of 15 patients tested.
• ESR and ANA were positive in 22% of patients. No correlation with clinical disease. Occasional nonspecific abnormalities in CBC.
• All other laboratory testing negative.
• CT scan
– 39% with abnormality
– Large vestibular aqueduct in 13%
– Cochlear dysplasia in 7%
– MRI added to diagnosis in 4, one of which related to hearing loss (fistulous connection from IAC to temporal bone)
• Authors concluded that routine laboratory evaluation should be reconsidered given its low diagnostic yield
• They supported routine use of EKG and CT scan.

• EKG – sudden childhood death
• CT – High incidence of abnormality
– Large vestibular aqueduct – avoid contact sports
– Used for preoperative information should bilateral SNHL develop
– Mondini malformation lead to further testing
• Syphilis
– Rare without classical stigmata (interstitial keratitis, Hutchinson’s teeth, mulberry molars, bilateral painless knee effusions, nasal septal perforation, saddle nose deformity)
– Simple treatment, potentially fatal
– Recommend testing with RPR, confirmation with TTPA
• GJB2 (Connexin 26)
– Screening only if result will affect future childhood planning
– Genetics consult warranted for counseling of results
- Fever or illness more than 3 weeks, gingival bleeding, bone or joint pain, signs of autoimmune disease, order CBC and ANA, ESR, RF
- Family history of progressive early onset hearing loss in first or second degree relative, order urinalysis, genetics consult
• Family history of progressive vision loss or visual complaints, order ophthalmology consult
• History of hematuria or family history of kidney failure, order urinalysis. If urinalysis positive order BUN, creatinine
• Thyroid goiter, signs of hypothyroidism, Mondini malformation, large vestibular aqueduct by CT scan, order thyroid function test, consider perchlorate test
• History of frequent urination, excessive thirst, order serum glucose
• History of progressive hearing loss, gait or vestibular symptoms, focal neurological symptoms, order MRI of brain and IAC’s
• History of neurofibroma, meningioma, glioma, schwannoma, juvenile posterior subcapsular lenticular opacity or family history of Neurofibromatosis type II, order MRI of brain and IAC’s.
Sudden Sensorineural Hearing Loss
• Incidence estimated between 5 and 20 per 100,000
• Most common between ages of 40 and 54
• Loss of at least 30dB in 3 contiguous frequencies in 72 hours or less
• 65% diagnosed will spontaneously recover within 20dB or greater than 50% of total loss

Sudden Sensorineural Hearing Loss
• Etiology
– Vascular compromise from hyperviscosity, embolic event, vasospasm.
– Intracochlear membrane rupture or perilymph fistulas
– Viral infection
– Autoimmune inner ear disease, systemic autoimmune disease (Cogan’s, Wegner’s, polyarteritis nodosa, temporal arteritis, Berger's, SLE)

• Diagnostic testing
– Serum Glucose
– T3, T4, TSH
– Lyme titer
– Cholesterol/Triglycerides
– Anti-hsp 70 (68KD heat shock protein)
Sudden Sensorineural Hearing Loss
• Serum Glucose
• Thyroid function studies
– Used to look for hemorrhagic etiology of SSNHL
– Patients likely to have other manifestations of coagulopathy
– Higher yield if patient currently on an anticoagulant
– Shown to decrease hearing in up to 30% of patients with active infection compared to controls.
– Literature shows 3 cases of SSNHL with positive HIV
– Low yield
– HIV treatment early improves life expectancy
• Lyme titer
– No literature case reports of Lyme disease as an etiology
– Recent history of tick exposure
– Low yield
• Gagnebin 2000 (French study)
– Analyzed screening HIV, Lyme, syphilis
– 102 charts reviewed
– Two patients with positive Lyme titers, not responding to treatment
– All HIV negative
– Latent syphilis without signs of neurosyphilis in one patient
– Concluded screening is low yield without history
• Anti-hsp70 (68KD heat shock protein)
– Thought to be a marker of autoimmune inner ear etiology
– Early studies have shown steroid responsiveness in patients with positive tests
– Samuelsson screened 27 with SSNHL and 100 controls. 19% and 14% respectively (not significant)
– Yeom in 2003 tested for anti-hsp 70 in 20 patients with rapidly progressive SNHL and 20 controls. No significant difference
• Anti-hsp70 (68KD heat shock protein)
– Testing is high yield
– Question as to validity of results
– Question of utility of positive results
(most patients treated with steroids)
• Cholesterol and Triglycerides
– Labyrinthine artery atherosclerosis as an etiology
– Friedrich – 49 patients with neurootologic symptoms. Increased LDL and LDL/HDL ratio as compared to controls
– Nuti – No significant difference in cholesterol and LDL/HDL ratio with controls

• Cholesterol and Triglycerides
– Ullrich – tested lipids and triglycerides in 24 patients with SSNHL. No significant difference from controls
– Kojima – 12 patients with SSNHL
• Event was at least 1 month prior study
• Patients with total cholesterol greater than 230mg/dL treated with diet and medications
• Significant improvement in 125-2000 Hz
– American College of Physicians recommends screening for lipid abnormalities in men 35-65 and women 45-65 years of age using total cholesterol level only.
– Cholesterol or triglyceride levels as an etiology of SSNHL likely low probability
– Testing in this age range is high yield

– Used to screen for acoustic neuroma
– Patients with acoustic neuroma present with SSNHL 10% of the time
– As high as 2.5% of all patients with SSNHL have an acoustic neuroma
– Able to screen for acoustic neuroma and other causes of hearing loss
– Aronzon – treated patients with SSNHL and MRI proven acoustic neuroma with high dose of steroids
• Improvement in hearing of all patients
• Response to steroids does not exclude acoustic neuroma
• All patients should be screened with RPR, confirmed with TTPA (treatable, life threatening, low cost)
• MRI in all patients, regardless of response to steroids
• Total cholesterol in men aged 35-65, women aged 45-65 if no testing in the last year
• HIV testing in all patients with high risk of STD, +/- in all patients
• ESR, ANA, RF in patients with history and physical findings of autoimmune etiology, response to steroid, but relapse after taper
Sudden Sensorineural Hearing Loss
• CBC, Thyroid function tests, PT, PTT, Lyme titers based on history or physical exam findings only
• 68 KD protein in research settings, +/- in response to steroids with relapse after steroid taper
Acoustic Neuroma
• 12 per million per year
• MRI can detect tumors as small as 3mm
• Gold standard for diagnosis is MRI of IAC’s with gadolinium
• Test cost at this institution is $3200 

Acoustic Neuroma
– Alternative to MRI for diagnosis
– MRI generally 5 times more expensive than ABR
– Decreased sensitivity
– Cost at this institution is $500
• Sensitivity of ABR
– Wilson 1992 – sensitivity of 85%, 67% for small tumors
– Chandrasekhar 1995 – sensitivity of 92%, 83% for small tumors
– Gordon 1995 – sensitivity 88%, 69% for small tumors
– Ruckershern 1996 – sensitivity of 63%, PPV 26%
• Robinette and Bauch
– Retrospective review to identify 95 patients with acoustic neuromas
– Divided into 3 groups
• High risk – asymmetric hearing loss of greater than 20 DB over three frequencies, greater than 30% decrease of word recognition
• Intermediate risk – SSNHL or unexplained persistent unilateral tinnitus
• Low risk – isolated vertigo or historically explained intermittent tinnitus or historically explained SNHL
• Used probability of acoustic in each group as (30%, 5%, 1%)
• Sensitivity of detecting tumors with ABR based on size (100% large, 93% medium, 82% small)
• Used PPV of 12% in ABR
• Calculated cost of MRI for patients in each group
• Calculated cost of ABR, and MRI for all ABR’s suggestive of acoustic neuroma
• Calculated cost difference of two groups based on risk from history and physical
• Calculated number acoustic neuromas missed if first screened with ABR
• High risk - $40,000, no missed tumors
• Intermediate risk - $900,000, clinician would miss 4 tumors in 900 patients screened
• Low risk – $1.7 million, 1 tumor missed out of 1600 screened
• Authors recommended clinical decision making with consideration of cost savings in intermediate to low risk groups

• MRI in:
– All patients with unilateral SNHL greater than 20dB difference from unaffected side not explained by history
– Word discrimination difference of 30% or greater from asymptomatic side
– Unilateral persistent tinnitus not explained by history
– Persistent vertigo
– Unilateral sudden SNHL, regardless of response to steroids

• ABR vs. MRI
– Historically explained unilateral tinnitus
– Historically explained hearing loss
– Isolated vertigo

• Number of diagnostic tests expanding
• Physicians asked more and more to evaluate medical necessity and cost benefit of diagnostic testing
• Research projects based on cost analysis
• Balance of cost containment and diagnostic accuracy

Jacques Peltier, MD
Francis B. Quinn, Jr., MD
University of Texas Medical Branch


  1. This post is really helpful to those who had just problems with their hearing. These things are really very informative.

  2. Will this be applicable for those who are suffering from hearing loss at young age?


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