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Progressive hearing loss in an infant in a neonatal intensive care unit as revealed by auditory evoked brainstem responses
Auris Nasus Larynx 29 (2002) 187– 190 www.elsevier.com/locate/anl
Case report
Progressive hearing loss in an infant in a neonatal intensive care unit as revealed by auditory evoked brainstem responses Lihui Huang a,*, Kimitaka Kaga a, Kazuhiro Hashimoto b a
Department of Otorhinolaryngology, Faculty of Medicine, Uni6ersity of Tokyo, Hongo 7 -3 -1, Bunkyo-ku, Tokyo 113 -8655, Japan b Neonatology Department, Matsudo City Hospital, Hongo, Matsudo-shi, Chiba-ken, Japan Received 21 April 2001; received in revised form 31 August 2001; accepted 21 September 2001
Abstract We herein report a case of a 14-month-old infant who revealed a progressive hearing loss by repeated auditory evoked brainstem responses (ABR) during his 1 year stay in the neonatal intensive care unit (NICU). He was born prematurely with asphyxia, hyperbilirubinemia and respiratory distress. During his 1 year stay in the NICU he was under constant mechanical ventilation. Repeated ABRs over this year initially showed normal waves but subsequently demonstrated progressive hearing impairment (HI) leading finally to no responses. Possible causes of this progressive deafness (PF) include the multiple problems of asphyxia, hyperbilirubinemia and pulmonary disorders. © 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Progressive deafness; Hearing impairment; Auditory evoked brainstem response (ABR); Neonatal intensive care unit (NICU)
1. Introduction
2. Case report
Progressive hearing loss during infancy is rare. However, repeated recordings of auditory evoked brainstem responses (ABRs) have made it possible to better document progressive infantile hearing impairment (HI). Most babies show normal ABRs during hearing screening at the time of discharge from the neonatal intensive care unit (NICU) but exceptional cases do develop HI. Prolonged mechanical ventilation using pancronium bromide due to respiratory distress or ototoxic drugs such as ethacrynic acid may provide clues to the etiology of this HI [1–3]. Saitoh et al. [4] reported on a NICU population of 69 premature infants with diverse perinatal complications who were tested for HI using ABR. Thresholds in infants who had both hyperbilirubinemia and respiratory disorders or asphyxia were elevated more than in infants with neither hyperbilirubinemia nor respiratory distress. We present a case report of a male infant whose progression of HI, from birth to 18 months of age, was revealed and documented by ABR.
This male infant was followed from birth to 18 months of age. His mother was hospitalized for bed rest from the 12th week of gestation until delivery because of threatened pressure abortion. The child was born in the 32nd week of gestation and presented with asphyxia during labor and hyperbilirubinemia. His birth weight was 1782 g, and the Apgar score was 1. Due to his respiratory distress at birth he was immediately hospitalized in the NICU of Matsudo City Hospital. He was intubated and mechanically ventilated and he received two exchange transfusions in NICU. Tracheomalacia was diagnosed and high positive end-expiratory pressure (PEEP) ventilation was administered. Gentamycin, 1 mg/body, was given by injection for 3 days because of bronchial inflammation.
* Corresponding author. Fax: + 81-3-38149486. E-mail address: [email protected] (L. Huang).
2.1. ABR recordings during NICU The ABR stimulus intensity was set at 105 dBnHL and alternating air conducted clicks were delivered at the rate of 10 clicks/s. Over the 1-year period this infant spent in the NICU the ABR was repeatedly recorded. At the first ABR, at 79 days after birth, the absolute
0385-8146/02/$ - see front matter © 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 3 8 5 - 8 1 4 6 ( 0 1 ) 0 0 1 4 0 - 7
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L. Huang et al. / Auris Nasus Larynx 29 (2002) 187–190
latencies of waves I and V were within normal limits and the wave I –V interval was normal (Fig. 1a). At 219 days and at 221 days both ABRs showed a progressively prolonged absolute latency of wave V and the disappearance of wave I (Fig. 1b and c). No discernible ABRs were evoked at 274 days of age (Fig. 1d). The latencies of waves I and waves V are summarized in Table 1.
3. Auditory testing at age of 14 months, 2 and 3 years Following release from the NICU of Matsudo City Hospital the child was referred to the otolaryngology department of the University of Tokyo for further study of his auditory function. At the age of 14 months he gave a response to the sound of a drum but not to that of a metal triangle (high frequency).
During conditioned orientation reflex audiometry (COR) the child gave appropriate head and body responses to pure tone auditory stimuli (250 Hz, 500 Hz, 1 kHz, 2 kHz) presented at 100 dB(SPL) (Fig. 2a). No discernible ABR waveforms were evoked at the stimulus level of 105 dBnHL (Fig. 2b). At the age of 1 year he had developed fairly good head control but he was not able to sit, crawl or stand. A developmental test for Japanese infants and young children indicated that his development was comparable to that of a 4-month old infant. Interestingly, no particular abnormalities were noted on the brain CT and MRI studies. At the age of 2 years the ABR again showed no response. Moreover, distortion product otoacoustic emissions (DPOAE) could not be elicited from either ear. At the age of 3 years, play audiometry indicated severe auditory threshold elevation (Fig. 3). He was able to walk only if one hand was supported.
Fig. 1. (a) ABR at 79 days after birth showing normal absolute latencies of waves I and V and a normal wave I – V interval, infant’s age considered. (b) ABR at 219 days after birth indicating the loss of wave I and prolonged latency of wave V. (c) ABR at 221 days after birth illustrating continuing prolongation of wave V latency. (d) ABR at 274 days showing no response.
L. Huang et al. / Auris Nasus Larynx 29 (2002) 187–190 Table 1
4. Discussion Repeated ABRs during the development of this high-risk NICU infant showed essentially normal waveforms and latencies during his initial testing (79 days old) and subsequent evidence of progressive HI leading finally to no response (221 days old). Only intense stimuli were used in this study so, even though the initial ABR was normal, normal hearing cannot be confirmed. However, the progression to abnormal is unequivocal. The exact pathophysiology of this progressive hearing loss is unknown but in this case some likely candidates are the multiple problems of asphyxia, hyperbilirubinemia, pulmonary disorders and ototoxicity. ABR have been recommended as an objective screening test for HI at the time of discharge from the NICU [5 – 8]. The incidence of HI among infants who were once admitted to NICUs is reported to be
189
between 2 and 10% [9,10]. However, 7–30% of infants with an abnormal ABR on initial screening will be found to have normal hearing on subsequent testing at 1–4 month of age [11,12]. Retesting of infants who passed the initial ABR screening is not customary between 3 and 12 months of age [13–15]. However, Nield et al. [1] reported 11 high risk infants who had normal ABRs at the time of discharge from the NICU and were found to have significant sensorineural hearing loss on follow-up between 13 and 48 months later. Kawashiro et al. [2] reported 10 pediatric cases whose ABRs were normal at the time of discharge from the NICU and who subsequently developed HI. None of these studies determined whether the hearing loss was progressive or of rapid onset. However, these and other studies [3] have implicated possible etiologies of this HI to be the use of panconium bromide, ototoxic drugs and ethacrinic acid. Finally, in the universal newborn hearing screening program we would like to emphasize the importance of evaluating for progressive HI in NICU babies, keeping in mind that the ABR screens only the mid to high frequency range of hearing.
Acknowledgements We thank Dr R. Marsh of Philadelphia Childrens’ Hospital and Dr D.W. Hughes of Eastmoreland Hospital, Portland, OR for scientific advice and English correction and H. Miyazaki for typing this manuscript.
Fig. 2. (a) Conditioned orientation reflex audiometry (COR) at 14 months of age indicating severe threshold elevation at 100 dB (triangles stimulation). (b) ABR at 14 months of age showed no response, consistent with the test at 274 days.
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Fig. 3. Play audiometry at 3 years of age demonstrated severe threshold elevation.
References [1] Nield TA, Schrier S, Ramos AD, Platzker AC, Warburton D. Unexpected hearing loss in high-risk infants. Pediatrics 1986;78:417 – 22. [2] Kawashiro N, Tuchihashi N, Araki A, Koga K, Ito Y, Kawano T. Hearing loss following discharge from the NICU. J Otolaryngol Jpn 1994;97:1056 –61. [3] Cheung P, Tyebkban IM, Peliowski A, Ainsworth W, Robertson CM. Prolonged use of pancronium bromide and sensorineural hearing loss in childhood survivors of congenital diaphragmatic hernia. Pediatrics 1999;135:233 –9. [4] Saitoh Y, Sakoda TK, Michio HZ, Fujiki YS, Shibano AK, Takahashi MS, Katoh HR, Dake YS, Enomoto TD. Auditory brainstem responses of premature infants in the neonatal intensive care unit. Pediatr Otorhinolaryngol Jpn 1997;98:34 – 8. [5] Schulman-Galambos C, Galambos R. Brainstem responses audiometry in newborns hearing screening. Acta Otolaryngol 1979;105:86 – 90. [6] Mjoens S, Langslet A, Tangsrud SE, Sundby A. Auditory brainstem responses in high-risk neonates. Acta Pediatr Scand 1982;71:711 – 5. [7] Stein LS, Ozdamar O, Kraus N, Paton J. Follow-up of infants screened by auditory brainstem response in the neonatal intensive care unit. J Pediatr 1983;1023:447 –53.
[8] Eviatar L. Evaluation of hearing in high-risk infant. Clin Perinatol 1984;11:153 – 73. [9] Galambos R, Hicks GE, Wilson MJ. The auditory brainstem respones reliably predicts hearing loss in graduates of a tertiary intensive care nursery. Ear Hear 1984;5:254 – 60. [10] Cox C, Hack M, Metz D. Brainstem evoked response audiometry: normative data from the preterm infant. Audiology 1981;20:53 – 64. [11] Roberts JV, Davis H, Phon GL, Reichert TJ, Sturtevant EM, Marshall RE. Auditory brainstem responses in preterm neonates: maturation and follow-up. Pediatrics 1982;101:251 – 63. [12] Downs DW. Auditory brainstem responses testing in the neonatal intensive care unit: a cautious response. ASHA 1982;4:1009 – 15. [13] Shanon DA, Felix JK, Krumholz A, Goldstein PJ, Harris KC. Hearing screening in high-risk newborns with brainstem auditory evoked potentials: a follow-up study. Pediatrics 1984;73:22 –6. [14] Alberti PW, Hyde ML, Riko K, Corbin H, Abramovich S. An evaluation of BAER for hearing screening in high-risk neonates. Laryngoscope 1983;93:1115 – 21. [15] Bradford BC, Baudin J, Conway MJ, Hazell JW, Stewart AL, Reynolds EO. Identification of sensory neural hearing loss in very infants by brainstem auditory evoked potentials. Arth Dis Chid 1985;60:105 – 9.
Case report
Progressive hearing loss in an infant in a neonatal intensive care unit as revealed by auditory evoked brainstem responses Lihui Huang a,*, Kimitaka Kaga a, Kazuhiro Hashimoto b a
Department of Otorhinolaryngology, Faculty of Medicine, Uni6ersity of Tokyo, Hongo 7 -3 -1, Bunkyo-ku, Tokyo 113 -8655, Japan b Neonatology Department, Matsudo City Hospital, Hongo, Matsudo-shi, Chiba-ken, Japan Received 21 April 2001; received in revised form 31 August 2001; accepted 21 September 2001
Abstract We herein report a case of a 14-month-old infant who revealed a progressive hearing loss by repeated auditory evoked brainstem responses (ABR) during his 1 year stay in the neonatal intensive care unit (NICU). He was born prematurely with asphyxia, hyperbilirubinemia and respiratory distress. During his 1 year stay in the NICU he was under constant mechanical ventilation. Repeated ABRs over this year initially showed normal waves but subsequently demonstrated progressive hearing impairment (HI) leading finally to no responses. Possible causes of this progressive deafness (PF) include the multiple problems of asphyxia, hyperbilirubinemia and pulmonary disorders. © 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Progressive deafness; Hearing impairment; Auditory evoked brainstem response (ABR); Neonatal intensive care unit (NICU)
1. Introduction
2. Case report
Progressive hearing loss during infancy is rare. However, repeated recordings of auditory evoked brainstem responses (ABRs) have made it possible to better document progressive infantile hearing impairment (HI). Most babies show normal ABRs during hearing screening at the time of discharge from the neonatal intensive care unit (NICU) but exceptional cases do develop HI. Prolonged mechanical ventilation using pancronium bromide due to respiratory distress or ototoxic drugs such as ethacrynic acid may provide clues to the etiology of this HI [1–3]. Saitoh et al. [4] reported on a NICU population of 69 premature infants with diverse perinatal complications who were tested for HI using ABR. Thresholds in infants who had both hyperbilirubinemia and respiratory disorders or asphyxia were elevated more than in infants with neither hyperbilirubinemia nor respiratory distress. We present a case report of a male infant whose progression of HI, from birth to 18 months of age, was revealed and documented by ABR.
This male infant was followed from birth to 18 months of age. His mother was hospitalized for bed rest from the 12th week of gestation until delivery because of threatened pressure abortion. The child was born in the 32nd week of gestation and presented with asphyxia during labor and hyperbilirubinemia. His birth weight was 1782 g, and the Apgar score was 1. Due to his respiratory distress at birth he was immediately hospitalized in the NICU of Matsudo City Hospital. He was intubated and mechanically ventilated and he received two exchange transfusions in NICU. Tracheomalacia was diagnosed and high positive end-expiratory pressure (PEEP) ventilation was administered. Gentamycin, 1 mg/body, was given by injection for 3 days because of bronchial inflammation.
* Corresponding author. Fax: + 81-3-38149486. E-mail address: [email protected] (L. Huang).
2.1. ABR recordings during NICU The ABR stimulus intensity was set at 105 dBnHL and alternating air conducted clicks were delivered at the rate of 10 clicks/s. Over the 1-year period this infant spent in the NICU the ABR was repeatedly recorded. At the first ABR, at 79 days after birth, the absolute
0385-8146/02/$ - see front matter © 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 3 8 5 - 8 1 4 6 ( 0 1 ) 0 0 1 4 0 - 7
188
L. Huang et al. / Auris Nasus Larynx 29 (2002) 187–190
latencies of waves I and V were within normal limits and the wave I –V interval was normal (Fig. 1a). At 219 days and at 221 days both ABRs showed a progressively prolonged absolute latency of wave V and the disappearance of wave I (Fig. 1b and c). No discernible ABRs were evoked at 274 days of age (Fig. 1d). The latencies of waves I and waves V are summarized in Table 1.
3. Auditory testing at age of 14 months, 2 and 3 years Following release from the NICU of Matsudo City Hospital the child was referred to the otolaryngology department of the University of Tokyo for further study of his auditory function. At the age of 14 months he gave a response to the sound of a drum but not to that of a metal triangle (high frequency).
During conditioned orientation reflex audiometry (COR) the child gave appropriate head and body responses to pure tone auditory stimuli (250 Hz, 500 Hz, 1 kHz, 2 kHz) presented at 100 dB(SPL) (Fig. 2a). No discernible ABR waveforms were evoked at the stimulus level of 105 dBnHL (Fig. 2b). At the age of 1 year he had developed fairly good head control but he was not able to sit, crawl or stand. A developmental test for Japanese infants and young children indicated that his development was comparable to that of a 4-month old infant. Interestingly, no particular abnormalities were noted on the brain CT and MRI studies. At the age of 2 years the ABR again showed no response. Moreover, distortion product otoacoustic emissions (DPOAE) could not be elicited from either ear. At the age of 3 years, play audiometry indicated severe auditory threshold elevation (Fig. 3). He was able to walk only if one hand was supported.
Fig. 1. (a) ABR at 79 days after birth showing normal absolute latencies of waves I and V and a normal wave I – V interval, infant’s age considered. (b) ABR at 219 days after birth indicating the loss of wave I and prolonged latency of wave V. (c) ABR at 221 days after birth illustrating continuing prolongation of wave V latency. (d) ABR at 274 days showing no response.
L. Huang et al. / Auris Nasus Larynx 29 (2002) 187–190 Table 1
4. Discussion Repeated ABRs during the development of this high-risk NICU infant showed essentially normal waveforms and latencies during his initial testing (79 days old) and subsequent evidence of progressive HI leading finally to no response (221 days old). Only intense stimuli were used in this study so, even though the initial ABR was normal, normal hearing cannot be confirmed. However, the progression to abnormal is unequivocal. The exact pathophysiology of this progressive hearing loss is unknown but in this case some likely candidates are the multiple problems of asphyxia, hyperbilirubinemia, pulmonary disorders and ototoxicity. ABR have been recommended as an objective screening test for HI at the time of discharge from the NICU [5 – 8]. The incidence of HI among infants who were once admitted to NICUs is reported to be
189
between 2 and 10% [9,10]. However, 7–30% of infants with an abnormal ABR on initial screening will be found to have normal hearing on subsequent testing at 1–4 month of age [11,12]. Retesting of infants who passed the initial ABR screening is not customary between 3 and 12 months of age [13–15]. However, Nield et al. [1] reported 11 high risk infants who had normal ABRs at the time of discharge from the NICU and were found to have significant sensorineural hearing loss on follow-up between 13 and 48 months later. Kawashiro et al. [2] reported 10 pediatric cases whose ABRs were normal at the time of discharge from the NICU and who subsequently developed HI. None of these studies determined whether the hearing loss was progressive or of rapid onset. However, these and other studies [3] have implicated possible etiologies of this HI to be the use of panconium bromide, ototoxic drugs and ethacrinic acid. Finally, in the universal newborn hearing screening program we would like to emphasize the importance of evaluating for progressive HI in NICU babies, keeping in mind that the ABR screens only the mid to high frequency range of hearing.
Acknowledgements We thank Dr R. Marsh of Philadelphia Childrens’ Hospital and Dr D.W. Hughes of Eastmoreland Hospital, Portland, OR for scientific advice and English correction and H. Miyazaki for typing this manuscript.
Fig. 2. (a) Conditioned orientation reflex audiometry (COR) at 14 months of age indicating severe threshold elevation at 100 dB (triangles stimulation). (b) ABR at 14 months of age showed no response, consistent with the test at 274 days.
190
L. Huang et al. / Auris Nasus Larynx 29 (2002) 187–190
Fig. 3. Play audiometry at 3 years of age demonstrated severe threshold elevation.
References [1] Nield TA, Schrier S, Ramos AD, Platzker AC, Warburton D. Unexpected hearing loss in high-risk infants. Pediatrics 1986;78:417 – 22. [2] Kawashiro N, Tuchihashi N, Araki A, Koga K, Ito Y, Kawano T. Hearing loss following discharge from the NICU. J Otolaryngol Jpn 1994;97:1056 –61. [3] Cheung P, Tyebkban IM, Peliowski A, Ainsworth W, Robertson CM. Prolonged use of pancronium bromide and sensorineural hearing loss in childhood survivors of congenital diaphragmatic hernia. Pediatrics 1999;135:233 –9. [4] Saitoh Y, Sakoda TK, Michio HZ, Fujiki YS, Shibano AK, Takahashi MS, Katoh HR, Dake YS, Enomoto TD. Auditory brainstem responses of premature infants in the neonatal intensive care unit. Pediatr Otorhinolaryngol Jpn 1997;98:34 – 8. [5] Schulman-Galambos C, Galambos R. Brainstem responses audiometry in newborns hearing screening. Acta Otolaryngol 1979;105:86 – 90. [6] Mjoens S, Langslet A, Tangsrud SE, Sundby A. Auditory brainstem responses in high-risk neonates. Acta Pediatr Scand 1982;71:711 – 5. [7] Stein LS, Ozdamar O, Kraus N, Paton J. Follow-up of infants screened by auditory brainstem response in the neonatal intensive care unit. J Pediatr 1983;1023:447 –53.
[8] Eviatar L. Evaluation of hearing in high-risk infant. Clin Perinatol 1984;11:153 – 73. [9] Galambos R, Hicks GE, Wilson MJ. The auditory brainstem respones reliably predicts hearing loss in graduates of a tertiary intensive care nursery. Ear Hear 1984;5:254 – 60. [10] Cox C, Hack M, Metz D. Brainstem evoked response audiometry: normative data from the preterm infant. Audiology 1981;20:53 – 64. [11] Roberts JV, Davis H, Phon GL, Reichert TJ, Sturtevant EM, Marshall RE. Auditory brainstem responses in preterm neonates: maturation and follow-up. Pediatrics 1982;101:251 – 63. [12] Downs DW. Auditory brainstem responses testing in the neonatal intensive care unit: a cautious response. ASHA 1982;4:1009 – 15. [13] Shanon DA, Felix JK, Krumholz A, Goldstein PJ, Harris KC. Hearing screening in high-risk newborns with brainstem auditory evoked potentials: a follow-up study. Pediatrics 1984;73:22 –6. [14] Alberti PW, Hyde ML, Riko K, Corbin H, Abramovich S. An evaluation of BAER for hearing screening in high-risk neonates. Laryngoscope 1983;93:1115 – 21. [15] Bradford BC, Baudin J, Conway MJ, Hazell JW, Stewart AL, Reynolds EO. Identification of sensory neural hearing loss in very infants by brainstem auditory evoked potentials. Arth Dis Chid 1985;60:105 – 9.