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Changes in the hearing thresholds of infants who failed the newborn hearing screening test and in infants treated in the neonatal intensive care unit.

Kang MY, Jeong SW, Kim LS - Clin Exp Otorhinolaryngol (2012)

Bottom Line: The aim of this study was to investigate changes in the hearing thresholds during the first year of life in infants who failed the newborn hearing screening (NHS) test and of infants treated in the neonatal intensive care unit (NICU).Of the 193 healthy infants who failed the NHS test, 60 infants (31%) had normal hearing acuity, 126 infants (65%) had sensorineural hearing loss (SNHL, ABR threshold ≥40 dB) and 7 infants (4%) had auditory neuropathy (AN).Irreversible intervention such as cochlear implantation should be considered with great caution within the first year after birth.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.

ABSTRACT

Objectives: The aim of this study was to investigate changes in the hearing thresholds during the first year of life in infants who failed the newborn hearing screening (NHS) test and of infants treated in the neonatal intensive care unit (NICU).

Methods: From March 2007 to November 2010, 193 healthy infants who failed the NHS test and 51 infants who were treated in the NICU were referred for evaluation of hearing acuity. Their hearing was evaluated using impedance audiometry, auditory brainstem response (ABR), and otoacoustic emission before 6 months of age, and follow-up hearing tests were administered before 12 months of age. Changes in their hearing thresholds were then analyzed.

Results: Of the 193 healthy infants who failed the NHS test, 60 infants (31%) had normal hearing acuity, 126 infants (65%) had sensorineural hearing loss (SNHL, ABR threshold ≥40 dB) and 7 infants (4%) had auditory neuropathy (AN). On the follow-up hearing tests, which were conducted in 65 infants, 6 infants showed a hearing threshold deterioration of more than 20 dB, and 19 infants showed a hearing threshold improvement of more than 20 dB. Of the 51 infants who were treated in the NICU, 38 infants (75%) had normal hearing acuity, 12 infants (24%) had SNHL, and one infant (2%) had AN. In the follow-up hearing tests, which were performed in 13 infants, one infant with normal hearing progressed to severe hearing loss. Five infants who had SNHL showed a hearing threshold improvement of more than 20 dB, and 4 infants recovered to normal hearing.

Conclusion: The hearing thresholds of infants with congenital SNHL can change during the first year of life; therefore, the importance of administration of follow-up hearing tests is emphasized. Irreversible intervention such as cochlear implantation should be considered with great caution within the first year after birth.

No MeSH data available.


Related in: MedlinePlus

Change in hearing thresholds of a healthy newborn. Initial auditory brainstem response (ABR) revealed that he had profound sensorineural hearing loss. His hearing improved to 70 dBnHL and then 50 dBnHL in follow-up hearing tests.
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Figure 5: Change in hearing thresholds of a healthy newborn. Initial auditory brainstem response (ABR) revealed that he had profound sensorineural hearing loss. His hearing improved to 70 dBnHL and then 50 dBnHL in follow-up hearing tests.

Mentions: On the other hand, hearing threshold improvements has also been reported in infants with AN and NICU infants (20-23). Madden et al. (20) observed that 50% of 18 children with AN demonstrated a spontaneous hearing improvement 1 to 15 months after diagnosis with AN, and four children did not require any hearing amplification because of spontaneous improvement. Hearing recovery in infants treated in the NICU has shown to be implicated in cleft palate, hyperbilirubinemia, prematurity, neonatal sepsis, or low birth weight (21-23). Cleft palate is frequently associated with abnormal Eustachian tube function, so otitis media with effusion at the time of initial hearing tests can cause an elevated threshold (21). Therefore, an otoscopic examination or a tympanogram is warranted in order to evaluate middle ear function with the ABR test, and the delay of wave I in the ABR waveform also should be cautiously examined. Neonates with hearing loss and hyperbilirubinemia can recover their hearing with normalization of the serum level of bilirubin, which can cause a transient abnormality of the auditory nerve and brainstem function (22). In severely premature babies, the delayed maturation of the auditory pathway may contribute to a spontaneous hearing threshold recovery (23). In our series, we were able to perform follow-up hearing tests in half (n=71) of the infants (n=146) confirmed to have SNHL or AN in the initial diagnostic hearing tests. Of these, 24 infants (34%) demonstrated hearing threshold improvements of more than 20 dB, and eight of them recovered to normal hearing. In particular, one healthy infant who was diagnosed with profound SNHL at 6 months of age showed a hearing improvement to 70 dBnHL and then 50 dBnHL on a series of follow-up hearing tests (Fig. 5). He was a candidate for CI at 6 months of age, but now, he demonstrates normal development in speech and language ability with assistance by a hearing aid alone.


Changes in the hearing thresholds of infants who failed the newborn hearing screening test and in infants treated in the neonatal intensive care unit.

Kang MY, Jeong SW, Kim LS - Clin Exp Otorhinolaryngol (2012)

Change in hearing thresholds of a healthy newborn. Initial auditory brainstem response (ABR) revealed that he had profound sensorineural hearing loss. His hearing improved to 70 dBnHL and then 50 dBnHL in follow-up hearing tests.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369979&req=5

Figure 5: Change in hearing thresholds of a healthy newborn. Initial auditory brainstem response (ABR) revealed that he had profound sensorineural hearing loss. His hearing improved to 70 dBnHL and then 50 dBnHL in follow-up hearing tests.
Mentions: On the other hand, hearing threshold improvements has also been reported in infants with AN and NICU infants (20-23). Madden et al. (20) observed that 50% of 18 children with AN demonstrated a spontaneous hearing improvement 1 to 15 months after diagnosis with AN, and four children did not require any hearing amplification because of spontaneous improvement. Hearing recovery in infants treated in the NICU has shown to be implicated in cleft palate, hyperbilirubinemia, prematurity, neonatal sepsis, or low birth weight (21-23). Cleft palate is frequently associated with abnormal Eustachian tube function, so otitis media with effusion at the time of initial hearing tests can cause an elevated threshold (21). Therefore, an otoscopic examination or a tympanogram is warranted in order to evaluate middle ear function with the ABR test, and the delay of wave I in the ABR waveform also should be cautiously examined. Neonates with hearing loss and hyperbilirubinemia can recover their hearing with normalization of the serum level of bilirubin, which can cause a transient abnormality of the auditory nerve and brainstem function (22). In severely premature babies, the delayed maturation of the auditory pathway may contribute to a spontaneous hearing threshold recovery (23). In our series, we were able to perform follow-up hearing tests in half (n=71) of the infants (n=146) confirmed to have SNHL or AN in the initial diagnostic hearing tests. Of these, 24 infants (34%) demonstrated hearing threshold improvements of more than 20 dB, and eight of them recovered to normal hearing. In particular, one healthy infant who was diagnosed with profound SNHL at 6 months of age showed a hearing improvement to 70 dBnHL and then 50 dBnHL on a series of follow-up hearing tests (Fig. 5). He was a candidate for CI at 6 months of age, but now, he demonstrates normal development in speech and language ability with assistance by a hearing aid alone.

Bottom Line: The aim of this study was to investigate changes in the hearing thresholds during the first year of life in infants who failed the newborn hearing screening (NHS) test and of infants treated in the neonatal intensive care unit (NICU).Of the 193 healthy infants who failed the NHS test, 60 infants (31%) had normal hearing acuity, 126 infants (65%) had sensorineural hearing loss (SNHL, ABR threshold ≥40 dB) and 7 infants (4%) had auditory neuropathy (AN).Irreversible intervention such as cochlear implantation should be considered with great caution within the first year after birth.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.

ABSTRACT

Objectives: The aim of this study was to investigate changes in the hearing thresholds during the first year of life in infants who failed the newborn hearing screening (NHS) test and of infants treated in the neonatal intensive care unit (NICU).

Methods: From March 2007 to November 2010, 193 healthy infants who failed the NHS test and 51 infants who were treated in the NICU were referred for evaluation of hearing acuity. Their hearing was evaluated using impedance audiometry, auditory brainstem response (ABR), and otoacoustic emission before 6 months of age, and follow-up hearing tests were administered before 12 months of age. Changes in their hearing thresholds were then analyzed.

Results: Of the 193 healthy infants who failed the NHS test, 60 infants (31%) had normal hearing acuity, 126 infants (65%) had sensorineural hearing loss (SNHL, ABR threshold ≥40 dB) and 7 infants (4%) had auditory neuropathy (AN). On the follow-up hearing tests, which were conducted in 65 infants, 6 infants showed a hearing threshold deterioration of more than 20 dB, and 19 infants showed a hearing threshold improvement of more than 20 dB. Of the 51 infants who were treated in the NICU, 38 infants (75%) had normal hearing acuity, 12 infants (24%) had SNHL, and one infant (2%) had AN. In the follow-up hearing tests, which were performed in 13 infants, one infant with normal hearing progressed to severe hearing loss. Five infants who had SNHL showed a hearing threshold improvement of more than 20 dB, and 4 infants recovered to normal hearing.

Conclusion: The hearing thresholds of infants with congenital SNHL can change during the first year of life; therefore, the importance of administration of follow-up hearing tests is emphasized. Irreversible intervention such as cochlear implantation should be considered with great caution within the first year after birth.

No MeSH data available.


Related in: MedlinePlus