Binaural auditory indices of the human immunodeficiency virus

The purpose of this investigation was to compare the results of the masking level difference (MLD), monaural and binaural auditory brainstem response measures (ABR and BI/ABR), and acoustic reflex thresholds (ARTs) for two groups of human immunodeficiency virus (HIV) positive subjects, 12 asymptomatic and 12 symptomatic, and a control group of 12 HIV-negative subjects.; The results of this study demonstrated differences between both symptomatic and asymptomatic HIV-positive subjects compared to the HIV-negative control subjects. Reduced magnitudes of the MLD and altered waveforms of the ABR and BI/ABR, as evidenced by prolonged absolute and interpeak latencies, degraded amplitudes, and/or abnormal waveform morphology, were seen in all 24 HIV-positive subjects in this study. The ART measure was not as sensitive a measure as the MLD and ABR and BI/ABR in demonstrating group differences. Only symptomatic HIV-positive subjects evidenced elevated or absent acoustic reflex thresholds. While no statistically significant relationship was proven among the MLD, ABR and BI/ABR, and ARTs, clearly an association exists between these measures as demonstrated by the discriminant analysis and MANOVA. The discriminant analysis correctly classified 100% of the HIV-positive subjects and 100% of the HIV-negative control subjects. The MANOVA differentiated between HIV-positive and control group subjects.; The MLD and auditory evoked potentials are two measures which are sensitive in determining lesions at the caudal brainstem level. These two measures, together with the acoustic reflex threshold, provide a powerful test battery which can be used in the detection and documentation of auditory dysfunction within the brainstem. These measures are non-invasive, cause no patient discomfort, and are cost-effective.