Objective: To characterize the evolution of hearing in patients undergoing conservative management
and presenting with hearing of 50 dB or better. To identify risk factors for hearing
loss or preservation. Additionally, a comparison is made between “hearing preservation,”
defined as “preservation within class,” and maintenance of PTA levels with respect
to the contralateral ear.
Design: Retrospective cohort study.
Materials and Methods: Our database of patients with sporadic acoustic neuromas was searched to identify
those presenting with a PTA of 50 dB or less and a minimal potential follow-up of
at least 2 years. Audiological and demographic data were analyzed to characterize
hearing evolution and risk factors. Hearing evolution was defined as change in PTA
of the affected ear (0.5, 1, 2, and 3 kHz) over time relative to the contralateral
ear. Statistical analysis employs SPSS with appropriate Chi-Square or t-tests.
Results: Of 196 patients identified, 132 had adequate data for analysis. Of the group as a
whole, 30% preserved hearing at a rate equal to or better than that in the contralateral
ear. This contrasts with 58% preserving hearing in the same “class” (defined in terms
of PTA). The mean hearing loss in the group as a whole (hearing-losing patients only)
was 4.1 dB (range, 0.12–25 dB). There were no significant risk factors for hearing
preservation.
Conclusions: With long-term follow-up, approximately 30% of patients presenting with serviceable
hearing can expect to preserve this hearing. This contrasts with a higher preservation
rate if preservation within class outcome measure is employed.
