Unilateral Sensorineural Hearing Loss

Introduction

• 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?

  

Overview

• 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

– SNHL

– 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

• ANA, ESR, RF

• BUN, Creatinine, Urinalysis

• Serum glucose

• Thyroid function tests, Perchlorate test

• RPR, TTPA

• GJB2 (Connexin 26)

• EKG

• CT, MRI

• 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

• ANA, ESR, RF

– 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

• RPR, TTPA

– 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

• EKG

– 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.

Conclusions

• 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

– CBC

– ESR, ANA, RF

– Serum Glucose

– T3, T4, TSH

– PT, PTT

– RPR, TTPA

– HIV

– Lyme titer

– Cholesterol/Triglycerides

– Anti-hsp 70 (68KD heat shock protein)

– MRI

Sudden Sensorineural Hearing Loss

• CBC

• ESR, ANA, RF

• Serum Glucose

• Thyroid function studies

• RPR, TTPA

• PT, PTT

– Used to look for hemorrhagic etiology of SSNHL

– Patients likely to have other manifestations of coagulopathy

– Higher yield if patient currently on an anticoagulant

• HIV

– 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

• MRI

– 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

Conclusions

• 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

Conclusions

• 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

• ABR

– 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

Conclusion

• 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

• MRI

– 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

Summary

• 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