Sociodemographic disparities in pediatric cochlear implantation outcomes: A systematic review.

OBJECTIVES: To determine the impact of sociodemographic factors on post-operative performance outcomes among PCI recipients across the world. METHODS: A qualitative systematic review of PubMed, Scopus, Web of Science, and Embase was undertaken for studies analyzing the association of sociodemographic factors with measures of PCI outcomes published before July 18, 2021. Study quality assessment tools from the National Institutes of Health (NIH) were used to assess for risk of bias. RESULTS: Out of 887 unique abstracts initially retrieved, 45 papers were included in the final qualitative systematic review. Sociodemographic disparities in PCI outcomes from 4702 PCI recipients were studied in 19 countries, with 14 studies conducted in the United States of America, published within the years of 1999 to 2021. Parental education and socioeconomic status (e.g. income) were the most investigated disparities in PCI outcomes with 24 and 17 identified studies, respectively. CONCLUSION: Socioeconomic status was a consistently reported determinant of PCI outcomes in the USA and elsewhere, and parental education, the most reported disparity, consistently impacted outcomes in countries outside the USA. This study is limited by our inability to perform a meta-analysis given the lack of standardization across measures of sociodemographic variables and assessment measures for PCI outcomes. Future studies should address the literature gap on racial and ethnic disparities among PCI outcomes and use standardized measures for sociodemographic variables and PCI outcomes to facilitate meta-analyses on the topic. Targeting the mechanisms of these disparities may mitigate the impact of the sociodemographic factors on PCI outcomes.

Responses of Neurons in the Medullary Lateral Tegmental Field and Nucleus Tractus Solitarius to Vestibular Stimuli in Conscious Felines.

Considerable evidence shows that the vestibular system contributes to adjusting sympathetic nervous system activity to maintain adequate blood pressure during movement and changes in posture. However, only a few prior experiments entailed recordings in conscious animals from brainstem neurons presumed to convey baroreceptor and vestibular inputs to neurons in the rostral ventrolateral medulla (RVLM) that provide inputs to sympathetic preganglionic neurons in the spinal cord. In this study, recordings were made in conscious felines from neurons in the medullary lateral tegmental field (LTF) and nucleus tractus solitarius (NTS) identified as regulating sympathetic nervous system activity by exhibiting changes in firing rate related to the cardiac cycle, or cardiac-related activity (CRA). Approximately 38% of LTF and NTS neurons responded to static 40° head up tilts with a change in firing rate (increase for 60% of the neurons, decrease for 40%) of ~50%. However, few of these neurons responded to 10° sinusoidal rotations in the pitch plane, in contrast to prior findings in decerebrate animals that the firing rates of both NTS and LTF neurons are modulated by small-amplitude body rotations. Thus, as previously demonstrated for RVLM neurons, in conscious animals NTS and LTF neurons only respond to large rotations that lead to changes in sympathetic nervous system activity. The similar responses to head-up rotations of LTF and NTS neurons with those documented for RVLM neurons suggest that LTF and NTS neurons are components of the vestibulo-sympathetic reflex pathway. However, a difference between NTS/LTF and RVLM neurons was variability in CRA over time. This variability was significantly greater for RVLM neurons, raising the hypothesis that the responsiveness of these neurons to baroreceptor input is adjusted based on the animal's vigilance and alertness.