Amikacin alters auditory brainstem conduction time in newborns

Hearing loss, auditory neuropathy, and neurological co-morbidity in children with birthweight <750 g

BACKGROUND AND AIMS

The current literature considers a birthweight <1,500 g as a risk factor for sensorineural hearing loss (SNHL, hearing threshold >25 decibels), auditory neuropathy (AN), and several neurological sequelae. The aim of the study was to determine the frequency and risk factors associated with SNHL, AN, and neurological morbidity in a group of children with birthweights of <750 g treated at a neonatal care unit and recruited into a long-term follow-up program.

METHODS

A case-control study was carried out. Inclusion criteria were birthweight <750 g and born between the years 2000 and 2010. We performed brainstem auditory-evoked potentials (BAEP), evoked otoacoustic emissions (EOAE) and free-field audiometry (FFA) in this population. Neonatal variables and procedures were compared between children with SNHL and children with normal bilateral hearing (NBH).

RESULTS

A total of 93 children with a mean age of 4 years were included in the follow-up. Six children (6.4%) had SNHL and 87 had NBH. We were unable to identify AN in the sample. Mean weight for this sample was 673 ± 68 g and gestational age 27.5 ± 2 weeks. Variables reflecting differences between groups included days under mechanical ventilation, furosemide treatment, and bronchopulmonary dysplasia. In the SNHL group, three patients had periventricular leukomalacia, two had hydrocephalus, and one patient had cerebral palsy.

CONCLUSIONS

Frequency of SNHL in children with birthweights <750 g was higher than in other premature infants and was related with mechanical ventilation, furosemide application, and bronchopulmonary dysplasia. Association with other neurological morbidities was frequent. Early diagnosis and intervention are required.

Effect of hearing aids on auditory function in infants with perinatal brain injury and severe hearing loss

BACKGROUND

Approximately 2-4% of newborns with perinatal risk factors present with hearing loss. Our aim was to analyze the effect of hearing aid use on auditory function evaluated based on otoacoustic emissions (OAEs), auditory brain responses (ABRs) and auditory steady state responses (ASSRs) in infants with perinatal brain injury and profound hearing loss.

METHODOLOGY/PRINCIPAL FINDINGS

A prospective, longitudinal study of auditory function in infants with profound hearing loss. Right side hearing before and after hearing aid use was compared with left side hearing (not stimulated and used as control). All infants were subjected to OAE, ABR and ASSR evaluations before and after hearing aid use. The average ABR threshold decreased from 90.0 to 80.0 dB (p = 0.003) after six months of hearing aid use. In the left ear, which was used as a control, the ABR threshold decreased from 94.6 to 87.6 dB, which was not significant (p>0.05). In addition, the ASSR threshold in the 4000-Hz frequency decreased from 89 dB to 72 dB (p = 0.013) after six months of right ear hearing aid use; the other frequencies in the right ear and all frequencies in the left ear did not show significant differences in any of the measured parameters (p>0.05). OAEs were absent in the baseline test and showed no changes after hearing aid use in the right ear (p>0.05).

CONCLUSIONS/SIGNIFICANCE

This study provides evidence that early hearing aid use decreases the hearing threshold in ABR and ASSR assessments with no functional modifications in the auditory receptor, as evaluated by OAEs.

Prenatal antecedents of newborn neurological maturation

Fetal neurobehavioral development was modeled longitudinally using data collected at weekly intervals from 24 to 38 weeks gestation in a sample of 112 healthy pregnancies. Predictive associations between 3 measures of fetal neurobehavioral functioning and their developmental trajectories to neurological maturation in the first weeks after birth were examined. Prenatal measures included fetal heart rate (FHR) variability, fetal movement, and coupling between fetal motor activity and heart rate patterning; neonatal outcomes include a standard neurologic examination (n = 97) and brainstem auditory evoked potential (BAEP; n = 47). Optimality in newborn motor activity and reflexes was predicted by fetal motor activity, FHR variability, and somatic-cardiac coupling predicted BAEP parameters. Maternal pregnancy-specific psychological stress was associated with accelerated neurologic maturation.

Antibacterial agents in pediatrics

Antibiotics are among the most widely prescribed therapeutic agents in children. Several new trends in antibiotic usage for pediatric care have emerged. New mechanisms of antibacterial resistance have required a broader repertoire of antibiotic usage, including new agents directed at multidrug resistance. After promotion of judicious antibiotic use, there has been a decline in the number of pediatric prescriptions for antibiotics. Recent legislation addresses the necessity for pediatric clinical drug trials, ensuring development of further antibacterial agents for use in pediatric patients.