Hearing Loss Throughout the Childhood Years: Identification and Intervention

1
Hearing Loss Throughout the Childhood Years
Identification and Intervention

• Eric D. Baum, MD

Connecticut Pediatric Otolaryngology New Haven
Madison North Haven
2
Congenital Hearing Loss

• Defined as at birth or before age 5
• Language acquisition completed
• 2.7 per 1000 children under age 5 in the U.S.
• Intervention before and after 6 months age has
  dramatically different outcomes
• Screening programs available in all states
• But not mandated in all
• Screening for delayed-onset causes not routine in
  U.S.

Morton CC, Nance WE. N Engl J Med 35420, May 18,
2006, p2151-64.
3
Smith RJ. Bale JF Jr. White KR. Sensorineural
hearing loss in children. Lancet. 365879-90,
2005.
4
Syndromic Hearing Loss

• Pendred
• Usher
• Branchio-oto-renal
• Waardenburg
• Jervell and Lange-Nielsen
• Alport
• CHARGE

5
Pendred Syndrome

• SNHL and thyroid abnormalities
• Goiter (usually post-puberty)
• Thyroid function usually normal in children.
• Inner ear malformations common (EVA, Mondini)
• Genetics Autosomal recessive
• Genetic testing is available pendrin SLC26A4

6
Usher Syndrome

• SNHL with retinitis pigmentosa
• Progressive visual loss blindness can occur
  teens-20s.
• Autosomal recessive, several genes
• Type I Usher syndrome most severe.
• Profound deafness at birth, severe vestibular
  dysfunction

7
Branchio-Oto-Renal Syndrome (BOR)

• Branchial abnormalities, SNHL, kidney anomalies
• Preauricular pits (82), abnormal external ears
• Malformations of ear canals, middle, inner ears
  common.
• Autosomal dominant
• BOR gene EYA1

8
Jervell and Lange-Nielsen Syndrome

• One of the Long QT syndromes
• SNHL with abnormal cardiac electrical
  repolarization
• Arrhythmias, syncope, sudden death
• Readily detected with EKG
• Profound bilateral SNHL at birth
• Rare, autosomal recessive
• KVLQT1 gene (potassium channel)

9
Alport Syndrome

• Hearing loss and nephritis (progressive
  degenerative renal disease)
• Most often X-linked
• Urinalysis may detect proteinuria, hematuria

10
CHARGE Syndrome

• Coloboma
• Cranial neuropathy
• Cochlear malformation and SNHL
• Usually conductive also
• Cardiac anomalies
• Genitourinary anomalies
• Growth retardation
• CHD7 gene sporadic and accounts for only about
  half of cases

11
Waardenburg Syndrome

• White forelock
• Dystopia canthorum
• Heterochromia irides
• Many genes, many subtypes

12
Non-Syndromic HL

• Isolated genetic HL without any other recognized
  abnormalities
• Two thirds of all congenital SNHL
• Over 50 genes new ones discovered every year
• Testing available for only a small few

13
Connexin 26 (GJB2)

• Most common hereditary SNHL
• Causes 50 of non-syndromic SNHL in US, Europe.
• Recessive inheritance
• 35delG extremely common (2.5 carrier rate)
• SNHL variable (severity, symmetry, progression).
• Genetic testing widely available

Smith RJ. Bale JF Jr. White KR. Sensorineural
hearing loss in children. Lancet. 365879-90,
2005.
14
Non-Genetic SNHL
15
Non-Genetic SNHL

• Inner ear malformations
• Although some are genetic
• Infectious / Inflammatory
• Ototoxicity
• Trauma
• Tumors

16
Inner Ear Malformations

• Surprisingly common
• 30- 35 of patients with SNHL will have
  malformations
• Even higher in unilateral SNHL (40-45)
• Malformations can occur in isolation, or as part
  of a syndrome
• Why is diagnosis important?
• Risk of meningitis
• Risk of progression of HL
• Complicates cochlear implantation

17
Inner Ear Malformations

• Enlarged vestibular aqueduct (EVA)
• Lots of others
• Cochlear dysplasia
• Mondini, Michel, etc.
• Malformed vestibule / semicircular canals
• Others
• Absent eighth nerve
• Absent cochlea
• Common cavity deformity

18
Enlarged Vestibular Aqueduct (EVA)
19
EVA

• Most common malformation of the inner ear (11 of
  all SNHL)
• Unilateral or bilateral
• SNHL can be progressive. In some cases,
  stepwise progression with minor head trauma
• Can occur
• By itself
• Along with other malformations
• As part of a syndrome (notably, Pendred)

20
Inflammatory Labyrinthitis

• Congenital Systemic
• TORCHS (toxo, rubella, CMV, herpes, syphilis)
• CMV can be progressive
• Acquired Systemic
• Mumps
• Measles
• Lyme
• CMV
• Influenza
• Herpes
• parainfluenza

• Acquired Local
• Otitis media ? labyrinthitis
• Meningitis
• Usually bilateral
• Most common acquired cause
• SNHL in 10-15 of cases
• Often severe
• Watch for ossification

Kutz JW Simon LM et al, Arch ORL-HNS132 Sept
2006, 941-945.
21
Other Ototoxic Insults

• Anoxia Hypoxia
• Birth trauma
• Prolonged NICU stay, ventilation, ECMO
• Prematurity
• Ototoxic Medications
• Aminoglycosides (possible genetic predisposition)
• Loop diuretics
• Hyperbilirubinemia
• Central damage ? Auditory Neuropathy
• Trauma
• Temporal bone fracture
• Barotrauma
• Noise-induced
• Tumors
• Rare, especially in children
• But in unilateral SNHL, must consider!

22
Evaluation of SNHL
23
Evaluation of SNHL

• Rarely reversible, always treatable
• Future expectations
• Understand cause
• Family counseling
• Associated disorders
• Develop relationship with an audiologist

24
History and Physical Examination

• Important, not often diagnostic
• Can place SNHL into categories and guide further
  workup
• History
• Characterize onset
• Identify risk factors and exposures
• Identify family history of SNHL
• Physical
• Identify syndromic features

25
HP Important Elements

• Passed newborn screen?
• Perinatal history
• Family history (aided before 40)
• Neonatal history
• Prematurity (lt 32 wks)
• NICU
• Mechanical ventilation
• Infections
• Hyperbilirubinemia (transfused?)
• TORCHS / maternal infections

26
HP in Young Children

• Infections, trauma, other systemic diseases
• Trauma, infections, diabetes, blood dyscrasias,
  autoimmune, malignancy, meningitis, middle ear
  disease, noise exposure
• Balance problems, learning problems, speech delay
• Any prior testing
• Changes, progression, fluctuation
• Other symptoms
• Visual, balance, tinnitus
• Family history

27
Physical Exam

• Usually normal
• Detect syndromic features
• Pigment anomalies (Waardenburg)
• Ear pits, branchial anomalies (BOR)
• Abnormal external ear (CHARGE, BOR)
• Craniofacial abnormalities
• Detect other pathology (like OM) that may be
  compounding the SNHL

28
Audiometric Evaluation

• Confirm hearing loss, severity
• Characterize the HL
• Type of HL SNHL, mixed
• Site of lesion (e.g., cochlear, retrocochlear)
• Behavioral audiometry (audiogram) is gold
  standard.
• Supplemental use of physiologic testing (ABR,OAE)
  when necessary.

29
Whats Next in the Workup?

• Start with HP and audiogram
• Address comorbidities
• Develop relationship early (for intervention,
  etc.)
• Great start to guide further workup
• Lots of available tests yield is very low
• Genetics accounts for more and more
• Most other causes are each very rare
• Consider imaging and genetics evaluation

30
Imaging

• Non-contrast CT of temporal bones
• Gold standard
• Quick, but may require sedation
• Involves ionizing radiation
• Excellent for almost all causes
• MRI with Fancy-Shmancy protocol
• Not much longer or more expensive
• No radiation
• Can visualize astonishing detail
• Certainly indicated in some unusual cases

Russo EE, Manolidis S. Amer J Otolaryngol 27
(2006) 166-172.
31
Genetic Evaluation Why?

• Expertise
• inheritance patterns
• recognizing genetic syndromes
• Can perform genetic testing
• Can conduct genetic counseling
• Anyone can order testing, but remember that
  someone needs to deal with the information
  afterward

Yaeger D McCallum J et al. Amer J Med Gen
140A827-836 (2006)
32
Genetics Not Just Lab Tests

• Lots of available tests
• Microarrays becoming more common
• Too much data to handle

sorta based on Preciado DM, Lim LH, et al
ORLHNS, 2004 Dec131(6)804-9.
Gardner P Oitmaa E et al. Pediatrics
188985-994, September 2006.
33
Too Many Other Tests As Well

• Serology (suspected viral, autoimmune, syphilitic
  labyrinthitis)
• CBC
• risk of thalassemia or sickle cell disease
• Fechtner syndrome
• Macrothrombocytopenia leukocyte inclusions
  (assoc with Alport syndrome)
• Chemistries
• BUN electrolyte abnormalities with renal
  dysfunction (e.g., Alport syndrome)
• Lipid profile
• Glucose
• Thyroid function tests
• Congenital or acquired hypothyroidism
• Pendred syndrome
• Autoimmune work-up
• ESR
• anticardiolipin antibodies
• immunoglobulins
• complement studies

34
Can We Get the Answers We Need in a More Rational
Way?
35
A Rational Stepwise Workup

• Preciado DA, et al (2004). A diagnostic paradigm
  for childhood idiopathicsensorineural hearing
  loss. Otolaryngol Head Neck Surg 131 804-9.
• Preciado DA, et al (2005). Improved Diagnostic
  Effectiveness with a Sequential Diagnostic
  Paradigm in Idiopathic Pediatric Sensorineural
  Hearing Loss Otol Neurotol 26610-615.
• Retrospective 810 children with SNHL, with 650
  idiopathic
• Prospective 150 children with idiopathic SNHL
• Diagnostic yield for studies, relationship to
  severity of HL and whether unilateral or
  bilateral

36
Stepwise Workup Preciado D, et al (2005).
37
Algorithm Issues

• Access to tests/consultants may change your
  algorithm
• Almost any non-shotgun approach is useful
• Knowledge rapidly evolving
• How soon do you need to know?
• Family planning vs. antiarrhythmic medication
• Doing double duty?
• Eye evaluation for cause and treatment

Purcell DD, Fischbein NJ, et al. Laryngoscope
116 August 2006, p. 1439-46.
Schrijver I and Chang KW. Intl J Ped ORL, 2006,
in press.
38
One Possible Algorithm

• 1. Known or suspected etiology (e.g., meningitis,
  trauma)
• a. At diagnosis
• Ophthalmology
• Additional tests and / or treatments only as
  clinically indicated by etiology or clinical
  course.
• Examples suspected Waardenburg, suspected BOR,
  meningitis
• b. Serial Audiograms

39
A Proposed Algorithm

• 2. Unilateral SNHL
• a. At diagnosis
• Imaging study
• Ophthalmology
• b. If imaging normal, consider Genetics referral
• c. Serial Audiograms

40
Algorithm, continued

• 3. Bilateral SNHL (unknown etio.)
• a. At diagnosis
• Imaging of temporal bone
• CT if Mixed HL or heading for CI
• Ophthalmology
• Genetics referral (ideally, specialist in HL)
• EKG
• UA
• Labs if clinically indicated (rarely)
• b. Serial Audiograms, other referrals p.r.n.

41
Management of SNHL
42
Management Principles

• Identify, prevent, treat associated disorders
• Optimization of other senory input
• Auditory Rehabilitation
• Amplification (hearing aids)
• Cochlear Implantation
• Educational Interventions
• Preferential seating
• In class amplifiers (FM systems)
• Speech / language/ auditory-verbal therapy
• Future

43
Treatable-Preventable Disorders

• Cardiac (prolonged QT) awareness, medication
• Meningitis vaccinations
• SNHL population, particularly those with
  malformations, at higher risk than general
  population.
• We recommend to PCP to vaccinate for hiB and
  pneumococcus for all patients with SNHL.
• Thyroid disease
• Meningitis steroids reduce the incidence of
  SNHL and improve survival
• Sudden SNHL high dose steroids /- antivirals
  may improve recovery of hearing if begun promptly.

44
Amplification

• Cant be overemphasized!
• Critical during early childhood (language)
• Classroom
• in-school speaker systems (FM systems)
• preferential seating
• Hearing aids
• Social acceptance / compliance problems

45
Cochlear Implantation

• Candidacy coordinated by audiologist
• Requies specific expertise
• Rapidly evolving field, indications, expectations
• Part of a process
• Much success in very young (lt 18 month) children
• Start the process early
• Ongoing technological advances and opportunities

46
Future Therapies

• Hair cell regeneration
• Auditory nerve regeneration

Izumikawa, et al. Auditory hair cell
replacement and hearing improvement by Atoh1 gene
therapy in deaf mammals. Nature Medicine  11, 271
- 276 (2005)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)
51

Morton C and Nance W. N Engl J Med
20063542151-2164
Morton C and Nance W. N Engl J Med
20063542151-2164
52
Other Genetic Diseases Associated with SNHL

• Sickle Cell Anemia
• Polycythemia
• Macrothrombocytopenia (Epstein syndrome)
• Hyperlipidemia
• Chronic leukemia
• Diabetes
• SNHL is almost never the presenting feature

53
Screening programs

• Universal Newborn Hearing Screening programs
  Mandated since 2000
• Goal detect any HL more than mild (30 dB) in all
  newborns in U.S.
• Allows early detection and early intervention
• ABR or OAE
• Pass or Refer, L and R ear
• Refer
• ? follow up testing
• ? confirmed ? referral to otolaryngologist