EAR ROUNDSClinical Clerks of Block 5A UP Medicine 2011Department of Otorhinolaryngology, UP-PGHJanuary 21, 2010

COMMON CAUSES OF HEARING LOSS

AMONG NEONATES

INTRODUCTION

NEONATAL HEARING LOSS• A significant disability which any delay in early

recognition, diagnosis and intervention will cause a significant detrimental impact on speech, language and cognitive abilities (Fakhim

2007).• Important to determine its prevalence,

frequency, usual causes and significant risk factors

Types of Hearing

Loss

Types of hearing loss

CONDUCTIVE HEARING LOSS• ANYTHING PREVENTS THE

TRANSMISSION OF SOUND FROM THE EXTERNAL ENVIRONMENT TO THE COCHLEA

cerumen cholesteatomaneoplasm

Types of hearing loss

SENSORINEURAL HEARING LOSS• DISRUPTIONS IN

TRANSMISSION AFTER THE COCHLEA

• MAY BE RESULTS OF HAIR CELL DESTRUCTION OR COCHLEAR NERVE DAMAGE

Types of hearing loss

MIXED HEARING LOSS

Categories of Hearing

Loss

Categories of hearing loss

American National Standards Institute defines hearing loss:

Slight hearing loss: 16-25 dB lost

Mild hearing loss: 26-40 dB lost

Moderate hearing loss: 41-55 dB lost

Severe hearing loss: 71-90 dB lost

Profound: > 90 dB lost

Epidemiology of Hearing

Loss

EPIDEMIOLOGY

• In the US, hearing loss occurs in about 10/1000 children1 / 1000 profound3-5 / 1000 mild-moderate10-20% acquired

EPIDEMIOLOGY• Hearing loss requiring intervention among NICU admitted patients ranges from 1 to 4%

• SNHL occurs in 9-27 per 1000 children worldwide

• Though no sex predilection is noted, hereditary causes may occur more frequently in one sex than the other

EPIDEMIOLOGY• Most hearing loss in children is congenital or acquired perinatally but may occur at any age

• Approximately 10-20% of all cases are acquired postnatally

EPIDEMIOLOGY

• Prior to routine neonatal hearing screening, hearing loss was usually diagnosed at 2.5 years, now it improved to 14 months

EPIDEMIOLOGY

•Suspicion & Detection– Parents: 2/3 of the

cases– Pediatricians: 10%– Other Healthcare providers: 15%

•The mean time from suspicion to diagnosis is about 9 months

High-Risk Criteria for HL in

Neonates & Infants

High risk criteria

• The dissemination of high-risk criteria for neonates and infants in 1990 did not notably alter the mean age at diagnosis.

• About 50% of children with SNHL do not meet any of the criteria listed, and only 10% of neonates have 1 or more of the high-risk criteria that prompt an evaluation.

High risk criteria

•These rates are among the reasons cited for the need for universal neonatal hearing screening.

•The goals of such screening are to identify children who are deaf or hard of hearing and to start intervention by age 6 months.

Neonates (birth to 28 d)• Family history of congenital or early SNHL• Congenital infection known to be associated

with SNHL• Craniofacial anomalies• Birth weight of more than 1500 g (<3.3 lb)• Hyperbilirubinemia over the exchange level• Exposure to ototoxic medications• Bacterial meningitis• Low APGAR scores at birth• Prolonged mechanical ventilation• Findings of a syndrome associated with SNHL

Infants (29 d to 2y)

• Concern about hearing, speech, language, and/or developmental delay

• Bacterial meningitis• Neonatal risk factors associated with SNHL

• Head trauma, especially with fracture of the temporal bone

• Findings of a syndrome associated with SNHL

• Exposure to ototoxic medications• Neurodegenerative disorders• Infectious diseases associated with SNHL