Maturation of Auditory Brainstem Responses in Babies from Birth to 6 Months of Age (original) (raw)
Related papers
Auditory brainstem response in premature and full-term children
International Journal of Pediatric Otorhinolaryngology, 2007
Objectives: To compare the absolute latencies of peaks I, III and V and interpeak intervals of premature and full-term children. Methods: Prospective, comparative cohort study. Study subjects were premature and full-term children with auditory brainstem response (ABR) measured at ages 4, 12 and 20 months. The children had previously undergone otorhinolaryngolic and audiologic evaluations to exclude those with altered hearing. Results: One hundred and twenty-four children were included in the study (73 premature). No differences were found between children of different sexes nor between the right and left ears of the individual children, so the statistical unit sed for the study was the ear. Using the t-test for independent samples, the absolute latencies of peaks I, III and IV and the interpeak intervals I-III, I-IV and III-V presented statistically significant differences between the groups at ages 4 and 12 months. At 20 months, only peak I failed to show a difference in absolute latency. Strong inverse correlation was found (Pearson's coefficient) between gestational age and absolute peak latency, as well as for interpeak intervals. Conclusions: Maturation of the auditory system, as measured by ABR, occurs differently between premature and full-term children, suggesting that gestational age be taken into consideration when using ABR in premature children younger than 20 months old. #
SHORT REPORT: ESTABLISHING NORMAL HEARING FOR INFANTS WITH THE AUDITORY STEADY-STATE RESPONSE
This study investigated the use of the dichotic multiple frequency ASSR technique for characterising normal hearing in a group of infants. A descriptive research design was implemented to describe ASSR thresholds obtained in 10 normal hearing infant ears (3 male, 2 female participants) between the age of 3 and 8 weeks. Normal hearing was controlled for by conducting a DPOAE screening test on all ears and ensuring no risk factors for hearing loss were present. Results indicated mean ASSR thresholds at 0.5, 1, 2, and 4 kHz to vary between 30 and 37 dB, ± 8 -11 dB within a range of 20 -50 dB HL. Eighteen percent of ASSR thresholds were obtained at 20 dB, 45% were obtained at 30 dB, and 38% were obtained at elevated levels of 40 and 50 dB. The recorded dichotic multiple frequency ASSR thresholds for infants with normal hearing were within the mild to moderate hearing loss range which makes differentiating between less severe degrees of hearing loss and normal hearing difficult. Until future research has been conducted, caution must be practiced when interpreting ASSR thresholds below 60 dB in young infants and additional techniques such as the ABR must be used to cross-check results.
Inconsistency of auditory middle latency and steady-state responses in infants
… /Evoked Potentials Section, 1988
Auditory middle latency and steady-state responses (MLR/SSRs) were recorded in normal infants (aged 3 weeks to 28 months) and adults. SSR amplitudes were maximum using stimulus presentation rates near 40 Hz in adults. By contrast, the infant data showed no consistent amplitude maximum across the rates tested (9-59 Hz). With the exception of the brain-stem response wave V to MLR Na deflection, MLR components in infants' responses to 10.85 Hz clicks did not show any consistent pattern. To investigate the hypothesis that the 40 Hz SSR is derived from overlapping of the 10 Hz MLR components, 43.4 Hz SSRs were synthesized from the responses recorded at 10.85 Hz and compared with those recorded at 43.4 Hz. The predictive accuracy of the synthesized 43.4 Hz SSRs was significantly better in adults than in infants. The results of these studies indicate the presence of large age-related differences in the auditory MLR and SSR, and in the relationship between the two responses.
Study of Hearing Loss in High Risk Infants using Brainstem Evoked Response Audiometry (BERA
1. Introduction: Speech is the primary mode of human communication, but its acquisition appears to rely upon auditory experiences during a critical period between the age of birth to 3yrs. Screening is one of the most important methods of early diagnosis hearing loss. Brain stem response audiometry is the method of choice for accurate detection of hearing threshold. The present study emphasizes the importance of using ABR as a screening tool for the detection of hearing impairment at an early stage which would have otherwise got unnoticed till about 2-3yrs. 2. Material and Method: The study was conducted on thirty normal and thirty high risk infants referred to the department of ENT, Rajendra Institute of Medical Sciences, Ranchi. Study Design: Comparative study After a detail history and clinical examination recording was done with AMPLAID MK 22 machines in a sound proof room. Sedation was used only when required. The hearing loss was quantified as mild, moderate and severe. An abnormal BERA necessitates a repeat test after three months. 3. Results: Study Group consisted of thirty infants. There were 8 infants with birth asphyxia, 10 infants with hyperbilirubinemia, 1 with cytomegalovirus infection, 5 infants with low birth weight, 2 infants with craniofacial anomalies, 4 infants with family history of hearing loss. The incidence of hearing loss in high risk group was 70%. P value <0.5 which is significant. The incidence of hearing loss on doing a repeat test was 60% which is clinically significant. Of the abnormal BERA readings four patients had bilateral mild hearing loss. Moderate hearing loss was found in five infants. This was bilateral in four cases and unilateral in one case. Eight infants had profound hearing loss. Here there were seven infants with bilateral hearing loss and one infant with unilateral hearing loss. One infants had maturational delay which was bilateral. Control Group: All the infants in the control group showed normal BERA readings. 4. Conclusion: The present study emphasizes the importance of using ABR as a screening tool for the detection of hearing impairment at an early stage which would have otherwise got unnoticed till about 2-3yrs. ABR audiometry because of its accuracy has emerged as a technique of choice in the screening infants as it is an objective test. There is also a need for large scale study on obtaining normal values and standardizing the procedures for effective applications.
Longitudinal electrophysiological study of auditory pathway in small for gestational age infants
CoDAS, 2014
PURPOSE: To follow the maturation of the auditory pathway of infants born small for gestational age term, by studying absolute and interpeak latencies of Auditory Brainstem Response (ABR) in the first six months of life.METHODS: Multicentric prospective longitudinal study. The ABR was carried out in the neonatal period in 96 newborn infants, 49 small for gestational age (SGA) and 47 appropriate for gestational age (AGA). Of these, 77 infants (39 SGA and 38 AGA) returned for a second evaluation. In the third evaluation, 70 infants (35 SGA and 35 AGA) returned.RESULTS: SGA and AGA did not present significant differences in the neonatal period and at three months of life. However, at six months, there was statistical significant difference between SGA and AGA groups for the latencies of wave III and interpeak I-III. Latencies of ABR waves decreased more rapidly in the first three months than the third to the sixth month of life for the SGA. AGA group showed progressive decrease in late...
Acta otorhinolaryngologica Italica : organo ufficiale della Società italiana di otorinolaringologia e chirurgia cervico-facciale, 2013
To compare objective and subjective protocols assessing hearing loss in young children and evaluate frequency-specific hearing impairment through a comparison between auditory steady state responses (ASSR), auditory brainstem responses (ABR), transient otoacoustic emissions and conditioned orientation reflex responses (COR). Thirty-five hearing-impaired children (20 male and 15 female), aged between 14 months and 4 years, participated in the study. Hearing threshold levels and peripheral auditory function were assessed by measurements of ABR, ASSR, otoacoustic emissions and COR. The analysis of the COR and ASSR variables showed significant correlations in the majority of tested frequencies. The data highlight a characteristic of the COR procedure, which is an underestimation of the hearing threshold in comparison to the ASSR estimate. The data show that the COR threshold assessment follows the pattern of the other two established electrophysiological methods (ABR, ASSR). The correla...