The Stacked ABR: A Sensitive and Specific Screening Tool for Detecting Small Acoustic Tumors

Abstract

The failure of standard ABR measures to detect small (≤1 cm) acoustic tumors has led to the use of enhanced magnetic resonance imaging (MRI) as the standard to screen for small tumors. This study investigates the suitability of the stacked ABR as a sensitive screening alternative to MRI for small acoustic tumors (SATs). The objective of the study was to determine the sensitivity and specificity of the stacked ABR technique for detecting SATs. A total of 54 patients with acoustic tumors identified by MRI that were either ≤1 cm in size or undetected by standard ABR methods, irrespective of size, were studied. A control population of 78 nontumor normal-hearing subjects was also tested. For comparison, two standard ABR measures (IT5 and I-V delay) were also analyzed. The stacked ABR demonstrated 95% sensitivity and 88% specificity; 100% sensitivity was obtained at 50% specificity. Standard ABR measures were much poorer in detecting these tumors. In conclusion, the stacked ABR can be used as a sensitive, widely-available, cost-effective, and comfortable tool for screening SATs.

Sudden Sensorineural Hearing Loss

“…If contrast cannot be used with the CT due to allergy, renal failure (CR > 2.5 mg/dL), myasthenia gravis or myeloma, then a CT of the brain and temporal bones without contrast can be performed, which typically can only detect tumors > 1.5 cm in diameter. Alternatively, in the presence of hearing thresholds <75dB, a stacked ABR could be performed (Don et al, 2005).…”

Interaural Stacked Auditory Brainstem Response Measures for Detecting Small Unilateral Acoustic Tumors

“…Our hypothesis [Don et al, 1997[Don et al, , 2005Don and Kwong, 2009] is that the failure of the standard clinical ABR measures to detect small tumors is due to their reliance on latency changes of wave V of the ABR and that (1) high-frequency fibers dominate the standard click-evoked ABR latency measure, (2) tumors will be missed if these high-frequency fibers are not sufficiently affected by the tumor, and (3) small tumors do not always affect the subset of high-frequency fibers sufficiently. In these studies, we also hypothesized that a solution to the problem of detecting small tumors is to Interaural Stacked Auditory Brainstem Responses Audiol Neurotol 2012;17:54-68 55 use a measure that assesses activity from essentially all nerve fibers, not just a subset.…”

“…We developed and investigated the Stacked auditory brainstem response (SABR) as a screening tool for small ( ^ 1 cm) unilateral acoustic tumors (vestibular schwannomas) that were missed by standard clinical auditory brainstem response (ABR) measures [Don et al, 1997[Don et al, , 2005; review by Musiek et al, 2007]. Our hypothesis [Don et al, 1997[Don et al, , 2005Don and Kwong, 2009] is that the failure of the standard clinical ABR measures to detect small tumors is due to their reliance on latency changes of wave V of the ABR and that (1) high-frequency fibers dominate the standard click-evoked ABR latency measure, (2) tumors will be missed if these high-frequency fibers are not sufficiently affected by the tumor, and (3) small tumors do not always affect the subset of high-frequency fibers sufficiently.…”

“…The proposed solution, the SABR, is related to the total amount of synchronous neural activity evoked by click stimulation. Using the derived-band ABR and stacking techniques, the SABR is formed by temporally aligning and summing the synchronous activity of octave-wide bands of activity initiated across the cochlea in response to click stimulation [Don et al, , 1997[Don et al, , 2005. Because the SABR is composed of neural activity initiated across the whole cochlea, reduction of activity by a small tumor will reduce the SABR amplitude.…”

Mapping auditory nerve firing density using high-level compound action potentials and high-pass noise masking

“…However, analysis of other response parameters such as fine-structure, amplitude, response area, and waveform morphology may expand the diagnostic utility of these measures. For example, Don et al (2005) demonstrated that their stacked auditory brainstem response (ABR) technique, which optimizes wave V amplitude by temporally aligning and summing derived-band ABRs, detects the presence of small acoustic neuromas with 95% sensitivity and 88% specificity. In a mouse model of temporary noise exposure, Kujawa and Liberman (2009) found that ABR amplitudes at high stimulus levels were better than thresholds at predicting auditory neuron degeneration.…”