Evaluation of Hearing Loss in Pediatrics

 
Click here for ASHA information on Pediatric Hearing Loss

Hearing impairment can be a major cause of developmental problems in pediatrics and early detection can lead to intervention and lessening of its effects on language development. It is important for the primary care physician to detect hearing deficits as early as possible. 

Incidence

1. Hearing deficits secondary to the presence of middle ear fluid is very common, mild, and usually transient. Its effects on the development of normal language is of questionable significance.
2. Approximately 1.5/1000 children have severe hearing deficits that will effect development of normal language.

Diagnosis

1. In some hospitals, all newborns are screened. May soon be required in Illinois.
2. Parental suspicion of the child not hearing should lead to a careful evaluation of the child. The diagnosis of hearing deficits is usually made by parents months before the doctors do. Children with profound hearing loss may coo and babble although the babbling sounds are not varied. Hearing impaired children usually are sociable and play normally. These characteristics may fool the evaluator. 
3. Be suspicious if there is no response to loud noises, no turning to noises by 6 months, no imitation of speech by 8-9 months, no apparent understanding by 1 year, and no apparent speech by 2 years of age. 
4. High risk groups that need screening
   
   1. 1500 grams at birth
   2. infants
   3. Infants requiring exchange transfusion for hyperbilirubinemia
   4. Exposure to ototoxic drugs such as aminoglycosides and furosemide
   5. Craniofacial anomalies and syndromes associated with hearing loss
   6. History of TORCH infections. 
   7. Positive family history of deafness
   8. History of bacterial meningitis

Types of Hearing Loss

1. Conductive- failure of the sound waves to be transmitted to the inner ear. Common causes are cerumen in the canal, narrow canal, middle ear effusion, ossicle damage, perforated drum, cholesteatoma
2. Sensorineural- failure of transduction of sound into neural activity. Hair cell damage from noise or trauma, cochlea damage or agenesis, ototoxic drugs, eighth nerve damage.
3. Central- tumors, demyelinating diseases, syndromes.

Important questions to ask in History

1. When was hearing problem first recognized?
2. Was the onset sudden or gradual? Often difficult to differentiate and asking about language milestones may give some clues to time of onset 
3. Other symptoms including sense of ear fullness, dizziness and vertigo, tinnitus 
4. History of trauma, infections, family history, developmental delay, birth history, drug exposure. 

Etiology

1. Genetic- Congenital
   1. Multiple systems- Pendred (goiter), Usher (blindness), and Waardenburg (hypopoigmentation, white forelock)
   2. Chromosomal abnormalities- Trisomy 13-15, trisomy 18 and 21
   3. Craniofacial- Treacher Collins, Piere Robin, Klippel Feil, Crouzons
   4. Lange Jewell Nielsen Syndrome associated with prolonged QT syndrome
2. Genetic Post-natal
   
   1. Alport 
   2. Neurofibromatosis
   3. Hunter and Hurler syndromes.
3. Non-genetic Congenital
   
   1. In-utero drug exposure- aminoglycosides
   2. Congenital infections -TORCH
4. Non-genetic post-natal
   
   1. Infections- meningitis, mumps and rubeola.
   2. ototoxic drugs- aminoglycosides, furosemide
   3. Noise
   4. Vascular injuries, trauma

Effect of Hearing Impairment

1. Dependent on the age of diagnosis, child's IQ, other developmental abnormalities, associated syndromes, and chromosomal abnormalities. 
2. Family support very important on prognosis
3. Even mild hearing impairment can affect development, personality, and school performance.

Evaluation of Hearing

1. Any child with poor school performance or history of inattentiveness needs their hearing screened. This includes all children with poor grades, ADD or ADHD, and emotional problems.
2. Testing - May estimate hearing ability by child's response to loud noise, older children's response to whispering simple commands or questions. hearing ticking of watch
3. Many offices are able to do audiograms for screening purposes. 
4. If there are any doubts about the child's ability to hear, referral should be made to trained audiologist for definitive results.

Management

1. The key to treatment is early detection and then a team approach involving the primary care doctor, otolaryngologist, audiologist, speech and language specialist, educational specialist, and the schools. 

References

1. Bachmann KR and Arvedson JC. Early Identification and Intervention for Children who are Hearing Impaired. Pediatrics in Review. 1998; 19:155-165.
2. Finitzo T, Albright K and O'Neal J. The Newborn with Hearing Loss: Detection in the Nursery. Pediatrics. 1998; 102(6):1452-1460.
3. Kveton, John. Hearing Loss in the Absence of Otitis Media. Pediatrics in Review. March 1994.
4. Mehl AL and Thomson V. Newborn Hearing Screening: The Great Omission. Pediatrics. 1998; 101(1):e4.
5. Rapin, Isabelle. Hearing Disorders. Pediatrics in Review. February 1993.
6. Sokol and Hyde  Hearing Screening. Pediatrics in Review May 2002
7. American Academy of Pediatrics.  Hearing Assessment in Infants and Children: Recommendations Beyond Neonatal Screening. Pediatrics Vol 111 No. 2 February 2003
8. Morton C. and Nance W. Newborn Hearing Screening- A Silent Revolution.  NEJM May 16, 2006
9. Papsin B. and Gordon K. Cochlear Implants for Children with Severe-to Profound Hearing Loss.  NEJM Dec 6, 2007
10. Declau F et al.  Etiologic and Audiologic Evaluations After Universal Neonatal Hearing Screening: Analysis of 170 Referred Neonates.  Pediatrics June 2008
11. American Academy of Pediatrics. Clinical Report-Hearing Assessment in Infants and Children: Recommendatons Beyond Neonatal Screening.  Pediatrics October 2009
12. AAP Cochlear Inplants in Children: Surgical Site Infections and Prevention and Treatment of Acute Otitis Media and Meningitis.  Pediatrics August 2010
13. Kral A and O'Donoghue G.  Profound Deafness in Childhood.  NEJM October 7, 2010