Distortion product otoacoustic emission data in perinatally HIV-infected and HIV-exposed but uninfected children and adolescents in the Pediatric HIV/AIDS Cohort Study

Reduced white matter maturation in the central auditory system of children living with HIV

Introduction

School-aged children experience crucial developmental changes in white matter (WM) in adolescence. The human immunodeficiency virus (HIV) affects neurodevelopment. Children living with perinatally acquired HIV (CPHIVs) demonstrate hearing and neurocognitive impairments when compared to their uninfected peers (CHUUs), but investigations into the central auditory system (CAS) WM integrity are lacking. The integration of the CAS and other brain areas is facilitated by WM fibers whose integrity may be affected in the presence of HIV, contributing to neurocognitive impairments.

Methods

We used diffusion tensor imaging (DTI) tractography to map the microstructural integrity of WM between CAS regions, including the lateral lemniscus and acoustic radiation, as well as between CAS regions and non-auditory regions of 11-year-old CPHIVs. We further employed a DTI-based graph theoretical framework to investigate the nodal strength and efficiency of the CAS and other brain regions in the structural brain network of the same population. Finally, we investigated associations between WM microstructural integrity outcomes and neurocognitive outcomes related to auditory and language processing. We hypothesized that compared to the CHUU group, the CPHIV group would have lower microstructural in the CAS and related regions.

Results

Our analyses showed higher mean diffusivity (MD), a marker of axonal maturation, in the lateral lemniscus and acoustic radiations, as well as WM between the CAS and non-auditory regions predominantly in frontotemporal areas. Most affected WM connections also showed higher axial and radial diffusivity (AD and RD, respectively). There were no differences in the nodal properties of the CAS regions between groups. The MD of frontotemporal and subcortical WM-connected CAS regions, including the inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and internal capsule showed negative associations with sequential processing in the CPHIV group but not in the CHUU group.

Discussion

The current results point to reduced axonal maturation in WM, marked by higher MD, AD, and RD, within and from the CAS. Furthermore, alterations in WM integrity were associated with sequential processing, a neurocognitive marker of auditory working memory. Our results provide insights into the microstructural integrity of the CAS and related WM in the presence of HIV and link these alterations to auditory working memory.

Auditory Function in the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol Up Young Adults: A Pilot Study

BACKGROUND

To collect and compare selected hearing measures in a pilot study of young adults with perinatally acquired HIV (YAPHIV) and those with perinatal HIV exposure who are uninfected young adults with PHEU (YAPHEU).

SETTING

Cross-sectional hearing measures in YAPHIV and YAPHEU enrolled in the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol (AMP) for Participants 18 Years of Age and Older (AMP Up).

METHODS

Pure-tone air conduction audiometry and distortion product otoacoustic emission (DPOAE) data were collected in 1 visit. A low-frequency pure-tone average (PTA) (LFPTA, at 0.25, 0.5, 1, and 2 kHz), a speech-frequency PTA (SFPTA, at 0.5, 1, 2, and 4 kHz), and a high-frequency PTA (HFPTA, at 3, 4, 6, and 8 kHz) were calculated. Hearing loss was defined as worse ear SFPTA of ≥20 dB HL. Separate linear regression models were fit for worse ear LFPTA, SFPTA, and HFPTA to assess associations with PHIV status. DPOAE signal-to-noise ratios (SNRs) were obtained at 3 frequencies in each ear.

RESULTS

Forty-seven YAPHIV and 9 YAPHEU completed hearing testing. All adjusted mean PTAs were similar between YAPHIV and YAPHEU. Hearing loss occurred more in YAPHIV (7/47, 15.2%; 95% CI: 6.3%-28.9%), compared with YAPHEU (0/9, 0%). No associations were detected between HIV disease severity measures and worse ear SFPTA. DPOAE SNRs were similar between YAPHIV and YAPHEU.

CONCLUSIONS

In this pilot study, peripheral hearing (ie, PTAs) and cochlear function (ie, DPOAEs) were similar between YAPHIV and YAPHEU. A larger study is warranted to confirm these findings.

Congenital Cytomegalovirus and Human Immunodeficiency Virus: Effects on Hearing, Speech and Language Development, and Clinical Outcomes in Children

Prenatal infections can have adverse effects on an infant's hearing, speech, and language development. Congenital cytomegalovirus (CMV) and human immunodeficiency virus (HIV) are two such infections that may lead to these complications, especially when left untreated. CMV is commonly associated with sensorineural hearing loss in children, and it can also be associated with anatomical abnormalities in the central nervous system responsible for speech, language, and intellectual acquisition. In terms of speech, language, and hearing, HIV is most associated with conductive and/or sensorineural hearing loss and expressive language deficits. Children born with these infections may benefit from cochlear implantation for severe to profound sensorineural hearing losses and/or speech therapy for speech/language deficits. CMV and HIV simultaneously present in infants has not been thoroughly studied, but one may hypothesize these speech, language, and hearing deficits to be present with potentially higher severity. Early identification of the infection in combination with early intervention strategies yields better results for these children than no identification or intervention. The purpose of this review was to investigate how congenital CMV and/or HIV may affect hearing, speech, and language development in children, and the importance of early identification for these populations.

Audiological assessment of children with HIV/AIDS: a meta-analysis

OBJECTIVE

To analyze the results of the audiological evaluation of children with HIV and AIDS.

DATA COLLECTION

Systematic review carried out in May 2019 in the Web of Science, PubMed, SciELO, and Scopus databases. Case reports and original articles were included, with no limitationsregarding country or year of publication.

DATA SYNTHESIS

278 articles were identified; 26 were included, in which HIV/AIDS was shown to be a risk factor for hearing loss (OR=5.364; p=0.00). The studies used different audiological exams, with varying methodologies. There was no difference regarding the type of hearing loss (p=0.119).

CONCLUSION

Longitudinal studies using the same type of examination at all stages are suggested, to allow better monitoring of the effects of HIV on the child's hearing,and studies that provide more methodological details. The knowledge of the influence of HIV on the child's auditory system may lead to the promotion of measures that minimize the prevalence of hearing loss, allow an early diagnosis and timely rehabilitation, so as not to compromise child development.

Hearing complaints in HIV infection originate in the brain not the ear

OBJECTIVE

Evidence suggests damage to brain auditory pathways, rather than inner ear damage, underlies the hearing difficulties HIV+ individuals report. But, antiretroviral therapy (ART) may affect the hearing system and also lead to hearing complaints.

DESIGN

Longitudinal study of HIV+ and HIV- individuals in Dar es Salaam Tanzania. A subset of this cohort started ART while in the study allowing the effects of ART to be studied directly.

METHODS

The ability to hear quiet sounds (pure-tone audiometry), cochlear outer hair cell function [distortion-product otoacoustic emissions (DPOAEs)], and gaps-in-noise detection thresholds (a central auditory processing test) were assessed at each visit. Visits were scheduled for 6-month intervals, but the number and spacing of visits varied. In the group that started ART while in the study, 107 HIV+ individuals had audiometric thresholds, 98 had DPOAEs, and 98 had gap measurements suitable for analysis. Data were analyzed using a linear mixed model with time and starting ART as fixed effects and individual participant repeated measures as random effects.

RESULTS

Starting ART did not affect audiometric or gap detection thresholds. The slope of the DPOAE amplitude vs. time relationship was more negative after starting ART but did not differ from the HIV- group. Gap thresholds were higher in the HIV+ group.

CONCLUSION

ART did not affect audiometric thresholds significantly suggesting common ART drugs are not major ototoxins. The gap detection results from the study show effects on central auditory processing in HIV+ individuals, supporting the origin of HIV-related hearing complaints in the central auditory system.

Auditory Impairments in HIV-Infected Children

OBJECTIVES

In a cross-sectional study of human immunodeficiency virus (HIV)-infected adults, the authors showed lower distortion product otoacoustic emissions (DPOAEs) in HIV+ individuals compared with controls as well as findings consistent with a central auditory processing deficit in HIV+ adults on antiretroviral therapy. The authors hypothesized that HIV+ children would also have a higher prevalence of abnormal central and peripheral hearing test results compared with HIV- controls.

DESIGN

Pure-tone thresholds, DPOAEs, and tympanometry were performed on 244 subjects (131 HIV+ and 113 HIV- subjects). Thirty-five of the HIV+, and 3 of the HIV- subjects had a history of tuberculosis treatment. Gap detection results were available for 18 HIV- and 44 HIV+ children. Auditory brainstem response results were available for 72 HIV- and 72 HIV+ children. Data from ears with abnormal tympanograms were excluded.

RESULTS

HIV+ subjects were significantly more likely to have abnormal tympanograms, histories of ear drainage, tuberculosis, or dizziness. All audiometric results were compared between groups using a two-way ANOVA with HIV status and ear drainage history as grouping variables. Mean audiometric thresholds, gap detection thresholds, and auditory brainstem response latencies did not differ between groups, although the HIV+ group had a higher proportion of individuals with a hearing loss >25 dB HL in the better ear. The HIV+ group had reduced DPOAE levels (p < 0.05) at multiple frequencies compared with HIV- subjects. No relationships were found between treatment regimens or delay in starting treatment and audiological parameters.

CONCLUSIONS

As expected, children with HIV+ were more likely to have a history of ear drainage, and to have abnormal tympanograms. Similar to the adult findings, the HIV+ group did not show significantly reduced audiometric thresholds, but did have significantly lower DPOAE magnitudes. These data suggest that (1) HIV+ children often have middle ear damage which complicates understanding the direct effects of HIV on the hearing system, and (2) even when corrected for confounders DPOAEs were lower in the HIV+ group. Previous studies suggest ototoxicity from antiretroviral drugs is an unlikely cause of the reduced DPOAE magnitudes. Other possibilities include effects on efferent pathways connecting to outer hair cells or a direct effect of HIV on the cochlea.

Hearing assessment data in HIV-infected and uninfected children of Cape Town, South Africa

Researchers are showing that the rate of hearing loss in children with perinatal HIV infection (PHIV) is higher than in HIV-unexposed, uninfected children. These data, however, have been collected mostly in the USA; extensive hearing data from low- and middle-income countries are lacking. The purpose of this study was to collect audiometric data in PHIV and HIV-uninfected children living in Cape Town, South Africa. Questionnaire data along with distortion product otoacoustic emissions (DPOAEs) and pure-tone testing were completed. Hearing loss was determined using the pure-tone thresholds defined as a pure-tone average (PTA) of 500, 1000, 2000, and 4000 Hz of >15 dB HL in the poorer ear. All data were compared between PHIV and HIV-uninfected children. Sixty-one (37 PHIV and 24 HIV-uninfected) children had hearing data. HIV status was not significantly associated with DPOAEs. The rate of conductive hearing loss was 11.5%; five PHIV and two HIV-uninfected children. The rate of any hearing loss was higher in PHIV children, but this difference was not statistically significant. PHIV children had a significantly higher mean PTA in the poorer ear than HIV-uninfected children. Conductive type of hearing loss was more common than sensorineural hearing loss. The underlying cause of hearing loss in the present study therefore remains unclear. Future research should include an examination of auditory neural function in an effort to determine the possible reason for differences in hearing.