Emily Zimmerman

Ototoxicity in preterm infants: effects of genetics, aminoglycosides, and loud environmental noise

Majority of hearing-loss cases with extremely preterm infants have no known etiology. There is a growing concern that the administration of aminoglycoside treatment in the noisy environment of the Neonatal Intensive Care Unit (NICU) may lead to hair-cell damage and subsequent auditory impairments. In addition, several mitochondrial DNA mutations are known to have been associated with aminoglycoside-induced hearing loss. This review provides a systematic analysis of the research in this area and elucidates the multifactorial mechanisms behind how mitochondrial DNA mutations, aminoglycosides and loud noise can potentiate ototoxicity in extremely preterm neonates. Recommended steps to minimize the risk of ototoxicity and improve clinical care for NICU infants are discussed.

Weight gain velocity in very low-birth-weight infants: effects of exposure to biological maternal sounds.

OBJECTIVE To examine the effects of biological maternal sounds (BMS) on weight gain velocity in very low-birth-weight (VLBW) infants (≤ 1,500 g). STUDY DESIGN An exploratory study with a matched-control design. A prospective cohort of VLBW infants exposed to attenuated recordings of BMS during their neonatal intensive care unit hospitalization were compared with retrospective controls matched 1:1 for sex, birth weight, gestational age, scores for neonatal acute physiology and perinatal extension (SNAPPE - II) scores (n = 32). RESULTS A linear mixed model controlling for gestational age, chronic lung disease, and days to regain birth weight revealed that infants receiving BMS significantly improved their weight gain velocity compared matched controls (p < 0.001) during the neonatal period. No differences were found on days spent nothing by mouth (p = 0.18), days until full enteral feeds (p = 0.51), total fluid intake (p = 0.93), or caloric intake (p = 0.73). CONCLUSION Exposure to BMS may improve weight gain velocity in VLBW infants. Further research is needed to evaluate the effectiveness of this noninvasive intervention during the neonatal period.

The multisensory brain and its ability to learn music

Playing a musical instrument requires a complex skill set that depends on the brains ability to quickly integrate information from multiple senses. It has been well documented that intensive musical training alters brain structure and function within and across multisensory brain regions, supporting the experience‐dependent plasticity model. Here, we argue that this experience‐dependent plasticity occurs because of the multisensory nature of the brain and may be an important contributing factor to musical learning. This review highlights key multisensory regions within the brain and discusses their role in the context of music learning and rehabilitation.

Clarifying nipple confusion

Nipple confusion, an infant’s difficulty with or preference for one feeding mechanism over another after exposure to artificial nipple(s), has been widely debated. This is in part due to conflicting statements, one by the American Academy of Pediatrics in 2005 suggesting that infants should be given a pacifier to protect against Sudden Infant Death Syndrome, and the other by the World Health Organization in 2009 stating that breastfeeding infants should never be given artificial nipples. Despite the limited and inconsistent evidence, nipple confusion is widely believed by practitioners. Therefore, there is a unique opportunity to examine the evidence surrounding nipple confusion by assessing the research that supports/refutes that bottle feeding/pacifier use impedes breastfeeding efficacy/success/duration. This review examined 14 articles supporting and refuting nipple confusion. These articles were reviewed using the Johns Hopkins Nursing Evidence-Based Practice Rating Scale. Based on our review, we have found emerging evidence to suggest the presence of nipple confusion only as it relates to bottle usage and found very little evidence to support nipple confusion with regards to pacifier use. The primary difficulty in conclusively studying nipple confusion is establishing causality, namely determining whether bottles’/pacifiers’ nipples are causing infants to refuse the breast or whether they are simply markers of other maternal/infant characteristics. Future research should focus on prospectively examining the causality of nipple confusion.

The Effects of Vestibular Stimulation Rate and Magnitude of Acceleration on Central Pattern Generation for Chest Wall Kinematics in Preterm Infants

Objective:To examine the role of vestibular inputs on respiratory and oromotor systems in healthy preterm infants.Study Design:A total of 27 preterm infants were quasi-randomly assigned to either the VestibuGlide treatment or control groups. VestibuGlide infants were held in a developmentally supportive position, given a pacifier and received a series of vestibular stimuli, counterbalanced across rate and acceleration conditions, 15 min 3 times per day for 10 days. The control infants were also held in a developmentally supportive position, given a pacifier for 15 min 3 times per day for 10 days but did not receive the VestibuGlide stimulation.Result:A multi-level regression model revealed that treatment infants increased their respiratory rate in response to vestibular stimulus, and that the highest level of vestibular acceleration delivered to the infants (0.51 ms−2) resulted in a significant increase in breaths per minute.Conclusion:Vestibular stimulation delivered to preterm infants before scheduled feeds effectively modulates respiratory rate and resets the respiratory central pattern generator.

Frequency Modulation and Spatiotemporal Stability of the sCPG in Preterm Infants with RDS.

The nonnutritive suck (NNS) is an observable and accessible motor behavior which is often used to make inference about brain development and pre-feeding skill in preterm and term infants. The purpose of this study was to model NNS burst compression pressure dynamics in the frequency and time domain among two groups of preterm infants, including those with respiratory distress syndrome (RDS, N = 15) and 17 healthy controls. Digitized samples of NNS compression pressure waveforms recorded at a 1-week interval were collected 15 minutes prior to a scheduled feed. Regression analysis and ANOVA revealed that healthy preterm infants produced longer NNS bursts and the mean burst initiation cycle frequencies were higher when compared to the RDS group. Moreover, the initial 5 cycles of the NNS burst manifest a frequency modulated (FM) segment which is a significant feature of the suck central pattern generator (sCPG), and differentially expressed in healthy and RDS infants. The NNS burst structure revealed significantly lower spatiotemporal index values for control versus RDS preterm infants during FM, and provides additional information on the microstructure of the sCPG which may be used to gauge the developmental status and progression of oromotor control systems among these fragile infants.

Transmission of biological maternal sounds does not interfere with routine NICU care: assessment of dose variability in very low birth weight infants

Maternal auditory stimulation is playing an increasing role in neonatal critical care. The goal of this study was to determine the dose variability in the administration of Biological Maternal Sounds (BMS) in Very Low Birth Weight (VLBW) infants as part of routine clinical care in the Neonatal Intensive Care Unit (NICU). The BMS intervention aimed to provide infants with individualized and biologically appropriate auditory stimuli, featuring acoustic stimuli from their own mothers. Sixteen preterm infants, born between 26-32 weeks gestational age (GA) and < 1,500 g, took part in this study. The study was conducted in a 46-bed, level-III NICU with four multi-patient pods. Mother’s voice and heartbeat sounds were recorded individually for each infant. Nurses were instructed to administer BMS 4x per 24-hour period by pressing play on an MP3 player connected to micro-speakers installed in the infant’s bed. BMS was initiated for each infant on approximately the sixth day of life (DOL) (mean = 5.78 ± 2) and continued until NICU discharge (mean length of stay = 46.62 ± 27.28). On average, infants received 80% of the target BMS dose. There were no significant differences in BMS administration between nursing shift (day vs. night; p = 0.35), bed type (crib vs. isolette; p = .41), and respiratory support (on vs. off oxygen; p = .93). There was a slight increase in the number of times BMS was initiated on days without exams versus days with exams; however, this difference was not statistically significant (p = 0.07). This study demonstrated the successful incorporation of maternal sounds into routine daily care in VLBW infants as early as DOL six until NICU discharge. The effectiveness of BMS needs to be further evaluated in a randomized controlled trial.

Do Infants Born Very Premature and Who Have Very Low Birth Weight Catch Up With Their Full Term Peers in Their Language Abilities by Early School Age

Purpose This study examined the extent to which children born preterm (< 37 weeks) and/or who have low birth weight (< 2,500 g) catch up with their full term peers in terms of their language abilities at early school age (≥ 5 to < 9 years). Method A systematic literature search identified empirical studies that fit the inclusion criteria. Data from the tests/questionnaires used for meta-analysis spanned the following language categories: total language score, expressive language, receptive language, pragmatics, phonological awareness, and grammar. The means (standard deviations) were extracted from the studies and were converted to mean difference and 95% confidence intervals to test for overall effect. Results Sixteen studies met the inclusionary criteria, for a total of 2,739 participants, of which 1,224 were born full term and 1,515 were born preterm. It is important to note that the preterm cohort represented very preterm infants who have a very low birth weight. The meta-analysis found that preterm infants scored significantly worse on total language (p < .001), receptive language (p < .001), expressive language (p < .001), phonological awareness (p < .001), and grammar (p = .03) than their full term peers. However, preterm infants did not score significantly worse than their peers on their pragmatics (p = .19). Conclusions Children born VPT and who have VLBW perform worse than their peers on their total language, receptive language, expressive language, phonological awareness, and grammar abilities by early school age. This information is important for speech-language pathologists to consider as children born prematurely reach school age.

Patterned Auditory Stimulation and Suck Dynamics in Full-Term Infants.

To determine whether patterned auditory stimuli, designed to mimic the natural burst‐pause pattern evident in non‐nutritive suck (NNS) with variations to the intraburst frequency, alter infants’ NNS and cardiorespiratory patterning.

Salivary FOXP2 expression and oral feeding success in premature infants

The objective of the study is to determine whether salivary FOXP2 gene expression levels at the initiation of oral feeding attempts are predictive of oral feeding success in the premature newborn. In this prospective study, saliva samples from 21 premature infants (13 males; birth gestational age [GA]: 30–34 wk) were collected around the initiation of oral feeding trials. Total RNA was extracted and underwent reverse transcription-quantitative polymerase chain reaction amplification for FOXP2. Oral feeding success was denoted by the days required to attain full oral feeds. A linear regression model, controlling for sex, birth GA, and weight at salivary collection, revealed that FOXP2 expression was significantly associated with oral feeding success (P = 0.002). The higher the expression level of FOXP2, the shorter the duration to feed. Salivary FOXP2 expression levels are significantly associated with oral feeding success in the preterm infant. FOXP2 may serve as a novel and informative biomarker to noninvasively assess infant feeding skills to reduce morbidities and length of stay.