Central Auditory Tests to Track Cognitive Function in People With HIV: Longitudinal Cohort Study

Background

The development of neurocognitive deficits in people infected with HIV is a significant public health problem. Previous cross-sectional studies have shown that performance on central auditory tests (CATs) correlates with cognitive test results in those with HIV, but no longitudinal data exist for confirmation. We have been performing longitudinal assessments of central auditory and cognitive function on a cohort of HIV-positive and HIV-negative individuals in Dar es Salaam, Tanzania to understand how the central auditory system could be used to study and track the progress of central nervous system dysfunction.

Objective

The goal of the project was to determine if CATs can track the trajectory of cognitive function over time in people diagnosed with HIV.

Methods

Tests of peripheral and central auditory function as well as cognitive performance were performed on 382 individuals over the course of 3.5 years. Visits were scheduled every 6 months. CATs included tests of auditory temporal processing (gap detection) and speech perception in noise (Hearing in Noise Test and Triple Digit Test). Cognitive tests included the Montreal Cognitive Assessment (MoCA), Test of Variables of Attention (TOVA), and subtests from the Cogstate battery. HIV-positive subjects were divided into groups based on their CAT results at their final visit (bottom 20%, top 20%, middle 60%). Primary analyses focused on the comparison between HIV-positive individuals that performed worse on CATs (bottom 20%) and the overall HIV-positive group (middle 60%). Data were analyzed using linear mixed-effect models with time as the main fixed effect.

Results

The group with the worst (bottom 20%) CAT performance showed a difference in trajectory for the MoCA (P=.003), TOVA (P<.048), and Cogstate (P<.046) over the course of the study period compared to the overall HIV-positive group. A battery of three CATs showed a significant difference in cognitive trajectory over a relatively short study period of 3.5 years independent of age (bottom 20% vs HIV-positive group).

Conclusions

The results of this study support the ability for CATs to track cognitive function over time, suggesting that central auditory processing can provide a window into central nervous system performance. CATs can be simple to perform, and are relatively insensitive to education and socioeconomic status because they only require repeating sentences, numbers, or detecting gaps in noise. These tests could potentially provide a time-efficient, low-cost method to screen for and monitor cognitive decline in patients with HIV, making them a useful surveillance tool for this major public health problem.

Adverse outcome pathway for aminoglycoside ototoxicity in drug-resistant tuberculosis treatment

Individuals treated for multidrug-resistant tuberculosis (MDR-TB) with aminoglycosides (AGs) in resource-limited settings often experience permanent hearing loss. However, AG ototoxicity has never been conceptually integrated or causally linked to MDR-TB patients' pre-treatment health condition. We sought to develop a framework that examines the relationships between pre-treatment conditions and AG-induced hearing loss among MDR-TB-infected individuals in sub-Saharan Africa. The adverse outcome pathway (AOP) approach was used to develop a framework linking key events (KEs) within a biological pathway that results in adverse outcomes (AO), which are associated with chemical perturbation of a molecular initiating event (MIE). This AOP describes pathways initiating from AG accumulation in hair cells, sound transducers of the inner ear immediately after AG administration. After administration, the drug catalyzes cellular oxidative stress due to overproduction of reactive oxygen species. Since oxidative stress inhibits mitochondrial protein synthesis, hair cells undergo apoptotic cell death, resulting in irreversible hearing loss (AO). We identified the following pre-treatment conditions that worsen the causal linkage between MIE and AO: HIV, malnutrition, aging, noise, smoking, and alcohol use. The KEs are: (1) nephrotoxicity, pre-existing hearing loss, and hypoalbuminemia that catalyzes AG accumulation; (2) immunodeficiency and antioxidant deficiency that trigger oxidative stress pathways; and (3) co-administration of mitochondrial toxic drugs that hinder mitochondrial protein synthesis, causing apoptosis. This AOP clearly warrants the development of personalized interventions for patients undergoing MDR-TB treatment. Such interventions (i.e., choosing less ototoxic drugs, scheduling frequent monitoring, modifying nutritional status, avoiding poly-pharmacy) will be required to limit the burden of AG ototoxicity.

Speech in Noise Perception as a Marker of Cognitive Impairment in HIV Infection

OBJECTIVES

Human immunodeficiency virus positive (HIV+) individuals report hearing difficulties, but standard audiological tests show no, or small, changes in peripheral hearing ability. The hearing complaints may reflect central nervous system (CNS) auditory processing deficits, rather than middle or inner ear problems, and may result from CNS damage due to HIV infection or treatment. If central auditory task performance and cognitive deficits in HIV+ individuals are shown to be related, then central auditory tests might serve as a "window" into CNS function in these patients.

DESIGN

We measured cognitive performance (Mandarin Montreal Cognitive Assessment [MoCA]) and speech in noise perception (Mandarin hearing-in-noise test [HINT]) in 166 normal-hearing HIV+ individuals (158 men, 8 women, average age 36 years) at the Shanghai Public Health Clinical Center in Shanghai, China. Data collection included audiometry, tympanometry, and the Amsterdam Inventory of Auditory Handicap (AIAH), which assesses the subjective ability to understand speech and localize sound.

RESULTS

Subjects had no middle ear disease and met criteria for normal-hearing sensitivity (all thresholds 20 dB HL or less). A significant negative relationship between speech reception thresholds (SRT) and MoCA scores (r = 0.15, F = 28.2, p < 0.001) existed. Stepwise linear regression showed that when the factors of age, MoCA scores, hearing thresholds, and education level were considered, only age and MoCA scores contributed independently to the SRT results (overall model r = 0.30, F = 38.8, p < 0.001). Subjective hearing complaints from the AIAH supported the HINT results. AIAH and MoCA scores were also related (r = 0.05, F = 8.5, p = 0.004), with those with worse MoCA scores having more problems on the AIAH. When the cohort was divided into those with normal and abnormal performance on the MoCA, those with abnormal performance on the MoCA had significantly higher average SRTs (p < 0.001).

CONCLUSIONS

Understanding speech in noise measured both objectively with the HINT and subjectively with the AIAH was inversely related to cognitive abilities despite a normal ability to hear soft sounds determined by audiometry. Although age was also an important independent factor affecting speech perception, the age relationship within the speech findings in this study may represent more than just age-related declines in speech in noise understanding. Although reliable data on disease duration are not available, the older members of this cohort likely had HIV longer and probably had more severe symptoms at presentation than the younger members because early detection and treatment of HIV in Shanghai has improved over time. Therefore, the age relationship may also include elements of disease duration and severity. Speech perception, especially in challenging listening conditions, involves cortical and subcortical centers and is a demanding neurological task. The problems interpreting speech in noise HIV+ individuals have may reflect HIV-related or HIV treatment-related, central nervous damage, suggesting that CNS complications in HIV+ individuals could potentially be diagnosed and monitored using central auditory tests.

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.

Brainstem Auditory Evoked Potential in HIV-Positive Adults

BACKGROUND

To characterize the findings of brainstem auditory evoked potential in HIV-positive individuals exposed and not exposed to antiretroviral treatment.

MATERIAL AND METHODS

This research was a cross-sectional, observational, and descriptive study. Forty-five HIV-positive individuals (18 not exposed and 27 exposed to the antiretroviral treatment - research groups I and II, respectively - and 30 control group individuals) were assessed through brainstem auditory evoked potential.

RESULTS

There were no significant between-group differences regarding wave latencies. A higher percentage of altered brainstem auditory evoked potential was observed in the HIV-positive groups when compared to the control group. The most common alteration was in the low brainstem.

CONCLUSIONS

HIV-positive individuals have a higher percentage of altered brainstem auditory evoked potential that suggests central auditory pathway impairment when compared to HIV-negative individuals. There was no significant difference between individuals exposed and not exposed to antiretroviral treatment.

Does the human immunodeficiency virus influence the vestibulocollic reflex pathways? A comparative study

BACKGROUND

This study compared vestibulocollic reflex and vestibulo-ocular reflex functioning in subjects with and without human immunodeficiency virus. It also described test results throughout progression of the disease and compared the results of human immunodeficiency virus positive subjects who were receiving antiretroviral therapies with those not receiving this treatment.

METHODS

Subjects comprised 53 adults with human immunodeficiency virus (mean age 38.5 ± 4.4 years) and 38 without human immunodeficiency virus (mean age 36.9 ± 8.2 years). Clinical examinations included cervical vestibular-evoked myogenic potential and bithermal caloric testing.

RESULTS

Abnormal cervical vestibular-evoked myogenic potential and caloric results were significantly higher in the human immunodeficiency virus positive group (p = 0.001), with an odds ratio of 10.2. Vestibulocollic reflex and vestibulo-ocular reflex involvement increased with progression of the disease. There were more abnormal test results in subjects receiving antiretroviral therapies (66.7 per cent) than in those not receiving antiretroviral therapies (63.6 per cent), but this difference was insignificant.

CONCLUSION

Human immunodeficiency virus seems to influence vestibulocollic reflex pathways. Combining cervical vestibular-evoked myogenic potential and caloric testing may be useful to detect early neurological involvement in human immunodeficiency virus positive subjects.

Hearing loss in people with HIV/AIDS and associated factors: an integrative review

Abstract

The current scientific literature reports on the incidence of hearing impairments due to HIV/AIDS, and the hearing changes can occur due to damage to the outer, middle or inner ear. Thus, it is important to study how these changes occur, the hearing loss and their associations with the HIV/AIDS infection.

Objective

To identify the factors related to hearing loss in people with HIV/AIDS in the global scientific literature.

Method

Study carried out an Integrative Review of the Literature. The key words used were: hearing loss, hearing disorders and deafness, separately associated to the keyword HIV on PUBMED, ScIELO, LILACS and ISI databases. We used complete original papers, of free access, in English, Spanish, French and Portuguese. Thirteen quantitative studies from 1994-2010 were selected.

Conclusion

We did not find any strong direct association between anti-retroviral therapy and hearing loss; however, there are indications of hearing loss in the population studied, and their associations and causes need to be better investigated.

Hearing loss and acquired immune deficiency syndrome: systematic review

PURPOSE: To investigate the occurrence of hearing loss in individuals with HIV/AIDS and their characterization regarding type and degree. RESEARCH STRATEGY: It was conducted a systematic review of the literature found on the electronic databases PubMed, EMBASE, ADOLEC, IBECS, Web of Science, Scopus, Lilacs and SciELO. SELECTION CRITERIA: The search strategy was directed by a specific question: "Is hearing loss part of the framework of HIV/AIDS manifestations?", and the selection criteria of the studies involved coherence with the proposed theme, evidence levels 1, 2 or 3, and language (Portuguese, English and Spanish). DATA ANALYSIS: We found 698 studies. After an analysis of the title and abstract, 91 were selected for full reading. Out of these, 38 met the proposed criteria and were included on the review. RESULTS: The studies reported presence of conductive, sensorineural, and mixed hearing loss, of variable degrees and audiometric configurations, in addition to tinnitus and vestibular disorders. The etiology can be attributed to opportunistic infections, ototoxic drugs or to the action of virus itself. The auditory evoked potentials have been used as markers of neurological alterations, even in patients with normal hearing. CONCLUSION: HIV/AIDS patients may present hearing loss. Thus, programs for prevention and treatment of AIDS must involve actions aimed at auditory health.

Systematic review of vestibular disorders related to human immunodeficiency virus and acquired immunodeficiency syndrome

INTRODUCTION

Disorders of the auditory and vestibular system are often associated with human immunodeficiency virus infection and acquired immunodeficiency syndrome. However, the extent and nature of these vestibular manifestations are unclear.

OBJECTIVE

To systematically review the current peer-reviewed literature on vestibular manifestations and pathology related to human immunodeficiency virus and acquired immunodeficiency syndrome.

METHOD

Systematic review of peer-reviewed articles related to vestibular findings in individuals with human immunodeficiency virus infection and acquired immunodeficiency syndrome. Several electronic databases were searched.

RESULTS

We identified 442 records, reduced to 210 after excluding duplicates and reviews. These were reviewed for relevance to the scope of the study.

DISCUSSION

We identified only 13 reports investigating vestibular functioning and pathology in individuals affected by human immunodeficiency virus and acquired immunodeficiency syndrome. This condition can affect both the peripheral and central vestibular system, irrespective of age and viral disease stage. Peripheral vestibular involvement may affect up to 50 per cent of patients, and central vestibular involvement may be even more prevalent. Post-mortem studies suggest direct involvement of the entire vestibular system, while opportunistic infections such as oto- and neurosyphilis and encephalitis cause secondary vestibular dysfunction resulting in vertigo, dizziness and imbalance.

CONCLUSION

Patients with human immunodeficiency virus and acquired immunodeficiency syndrome should routinely be monitored for vestibular involvement, to minimise functional limitations of quality of life.

Manifestações audiológicas em crianças e adultos com AIDS

TEMA: a literatura relata a ocorrência de alteração auditiva em pacientes com HIV/AIDS, podendo esta ser decorrente de comprometimentos na orelha externa, média e/ou interna. OBJETIVOS: caracterizar e comparar os resultados da avaliação audiológica e do Potencial Evocado Auditivo de Tronco Encefálico de crianças e adultos com AIDS. MÉTODOS: foram submetidos à avaliação audiológica e eletrofisiológica (Potencial Evocado Auditivo de Tronco Encefálico) 51 crianças e 22 adultos com AIDS (grupos pesquisa I e II respectivamente) e 50 crianças e 25 adultos saudáveis (grupos controle I e II respectivamente), com idade entre três e 10 anos (crianças) e entre 18 e 50 anos (adultos). RESULTADOS: nas crianças com AIDS foram mais frequentes as alterações de orelha média e nos adultos as de orelha interna, bem como maior ocorrência de resultados alterados no potencial evocado auditivo de tronco encefálico nos adultos quando comparados às crianças. CONCLUSÃO: crianças e adultos com AIDS apresentam alterações na avaliação audiológica e no potencial evocado auditivo de tronco encefálico, sugestivas de comprometimento das vias auditiva periférica e central. Os resultados enfatizam a eficácia da utilização dos testes eletrofisiológicos da audição para melhor definição do grau de lesão encefálica em pacientes com AIDS, permitindo ainda a monitorização da velocidade de evolução da doença.

Saúde auditiva, o vírus da imunodeficiência humana e a síndrome da imunodeficiência adquirida: uma revisão

TEMA: a Síndrome da Imunodeficiência Adquirida (SIDA/AIDS) é causada pelo Vírus da Imunodeficiência Humana (VIH/HIV), e resulta numa imunidade reduzida, o que torna o indivíduo mais susceptível a doenças e infecções oportunistas. Com o avanço da doença as estruturas do sistema auditivo central podem ser comprometidas pela ação direta do vírus ou decorrente de infecções secundárias e neoplasias. O portador do HIV/AIDS pode também se tornar mais vulnerável a outras patologias do ouvido. OBJETIVO: o objetivo desta revisão foi exploratório, visando identificar os possíveis pontos de interseção entre distúrbios auditivos e a Síndrome da Imunodeficiência Adquirida. Realizou-se uma revisão da literatura sobre a saúde auditiva dos portadores de HIV/AIDS e foi discutido o impacto potencial de patologias auditivas na qualidade de vida. CONCLUSÃO: a literatura sugere que várias possiveis associações existam entre os distúrbios auditivos e a Síndrome da Imunodeficiência Adquirida e o Vírus da Imunodeficiência Humana. Profissionais de saúde, inclusive aqueles dos serviços públicos no Brasil, deveriam examinar a necessidade de iniciativas de saúde auditiva dirigida aos portadores de HIV/AIDS para prevenir patologias auditivas ou reduzir seu impacto na qualidade de vida.

Potenciais evocados auditivos de longa latência em adultos com HIV/Aids

TEMA: potenciais evocados auditivos de longa latência. OBJETIVO: caracterizar os potenciais evocados auditivos de longa latência (Peall) de indivíduos com HIV/Aids comparando com os obtidos no grupo controle. MÉTODO: a casuística foi composta por 21 indivíduos com HIV/Aids pertencentes ao grupo pesquisa (14 do gênero masculino e sete do gênero feminino) com idade entre 31 e 48 anos e 21 indivíduos saudáveis pertencentes ao grupo controle (cinco do gênero masculino e 16 do gênero feminino) com idade entre 19 e 36 anos. Foram analisados os valores de latência e amplitude da onda P300, latência das ondas N1 e P2 e amplitude N1-P2. Os eletrodos foram colocados nas posições A1, A2, Cz e Fpz. RESULTADOS: no P300 observou-se que o grupo com HIV/Aids apresentou maiores valores de latência (p-valor = 0,010) e menores de amplitude (p-valor = 0,021) quando comparados com o grupo controle. Na análise do complexo N1-P2, ao comparar os grupos, verificou-se que o grupo pesquisa apresentou maiores valores de latência tanto para a onda N1 (p-valor = 0,035) como para a onda P2, porém esta última sem diferença estatisticamente significante. Com relação à análise da amplitude N1-P2, verificou-se que o grupo controle apresentou maiores valores, sendo esta diferença estatisticamente significante quando comparada ao grupo pesquisa. CONCLUSÃO: os achados do presente estudo mostraram que indivíduos com HIV/Aids apresentam alterações nos Peall, sugerindo comprometimento nas áreas corticais do sistema auditivo e mostrando a importância destes testes na avaliação audiológica de indivíduos com HIV/Aids.