In this study which was undertaken to determine the auditory and vestibular status in HIV infected patients, we sought to determine if there was any difference in the findings between HIV seropositive asymptomatic patients and HIV seropositive patients with AIDS. Also, the significance of the audio-vestibular dysfunction noted in HIV infected patients was determined by including a control group.
Hausler et al
] noted normal hearing threshold in the asymptomatic HIV positive patients, the criteria for abnormality being thresholds > 20 dB (500 - 200 Hz). In this study among the asymptomatic HIV seropositive, as many as 16 patients (50%) were detected to have a hearing loss (thresholds > 20 dB at 500-8000 Hz). In another study among 128 serologically positive active army recruits, Bell et al
] detected hearing loss in 20.9% recruits (threshold > 15 dB). Among the patients with AIDS, we found hearing loss in about 50% cases which was in agreement with the findings of a prospective study of 53 patients with AIDS at the San Francisco general hospital.[6
] Evaluating otologic disease in patients with AIDS in a five-year retrospective study at the New York University Medical Center, Bellevue hospital center, 26 patients with documented otologic symptoms (hearing loss 62%, otalgia 50%, otorrhea 31%, vertigo 15% and tinnitus 15%) were found.[5
] In our study, only two patients were symptomatic. One patient complained of blocked sensation in the ears and the other complained of vertigo. Chandresekar et al
] reported that a third of HIV infected patients have significant otologic complaints or findings. Sensorineural hearing loss in patients with AIDS has been attributed to iatrogenic causes (ototoxic medications), opportunistic infections of nervous system (cryptococcal meningitis, tuberculous meningitis, viral pathogens like cytomegalovirus, herpes virus,), otosyphilis, malignancy and progressive multifocal leukoencephalopathy (PML) or AIDS encephalopathy or AIDS dementia complex.[6
] In our study despite the fact that we had only two patients with cryptococcosis, one patient with HIV encephalopathy and one patient with TB meningitis, and the fact that we excluded those patients with a previous history of ototoxic drug intake, as many as 37% of cases in group 2 had a sensorineural hearing loss with two patients having a conductive hearing loss in lower frequencies and sensorineural hearing in higher frequencies, three patients had asymmetrical hearing loss. Teggi et al
] reported that the incidence of peripheral vestibular disorders remained almost same among the various classes of HIV infected patients, and this was in agreement with our study.
Pappas et al
] investigating the presence of pathogens in the cochlea of AIDS cases, found extracellular viral-like particles with morphologic characteristics of HIV-1 on the tectorial membrane in three cases. Numerous viral-like particles appearing essentially similar to identified HIV-1 particles in infected lymphocyte cultures were found within the cytoplasm of the connective tissue cells. This demonstration of viral-like particles and cochlear pathology might explain the auditory manifestations associated with HIV infection. In another study by Pappas et al
] pathological changes were identified in the labyrinth wall, the epithelial lining and the maculae and cristae. Cytological changes in hair cells included inclusion bodies, viral-like particles and hair bundle malformations. Epithelial lining cells, supporting cells and connective tissue cells had inclusions and viral-like particles. These findings together with that of the cochlear study provides an insight into the likely pathogenesis of viral-induced hearing loss and vestibular impairment in HIV infected patients.
The otopathology could be at multiple sites along the auditory and vestibular pathway and the prime cause of the otopathology could be due to the HIV virus itself as there was no statistically significant difference in the hearing loss and vestibular dysfunction between HIV seropositive asymptomatic patients and those with AIDS.
With increasing number of patients with HIV infection, otolaryngologists need to be aware that the HIV virus could result in audio-vestibular dysfunction. Initiating anti retroviral therapy (ART) in HIV positive individuals may also compound the audio-vestibular dysfunction as some of the agents like nucleoside analog reverse transcriptase inhibitors (NRTIs)may have ototoxic side effects example:.[17
] So these individuals need to be screened before starting the ART treatment.