Auditory brain stem response in small acoustic neuromas.

OBJECTIVE

The auditory brain stem response (ABR) has been criticized recently as an insensitive measure for the detection of small acoustic neuroma (AN). This study was undertaken to evaluate our experience with the efficacy of ABR in detection of small tumors.

STUDY

DESIGN

Retrospective case review. Twenty-five patients with surgically proven small ANs measuring 1 cm or less were reviewed. In addition, 568 patients who underwent screening ABR were reviewed to evaluate the rate of false positive results at our institution.

RESULTS

ABR was abnormal in 92% of patients with small AN in this series. Screening ABR was abnormal in approximately 19% of cases, one-third of which were found to have AN on magnetic resonance imaging testing.

CONCLUSION

With strict adherence to optimal technique and evaluation criteria, the ABR remains a viable option for AN screening, especially in elderly patients or when there is a low index of suspicion.