COMPARISON OF PROMONTORY STIMULATION TEST RESULTS BETWEEN DIFFERENT SUBSETS OF PATIENTS WITH HEARING LOSS: A NEW APPROACH IN NEUROTOLOGIC DIAGNOSIS

Abstract

Promontory stimulation testing is both a valuable diagnosic tool and a crucial step in candidate selection for cochlear implantation. In this study we have compared the promontory stimulation test results between different subsets of patients with hearing loss in order to clarify the aspects of promontory stimulation which correlate best with the patients'characierisiics. Patients with severe to profound hearing loss underwent Promontory Stimulation as well as a number of other diagnostic tests. One hundred and eighty eight ears comprised the study population and were grouped into congenital, non-congenital, cochlear, reirocochlear, sudden, and progressive hearing loss groups. The congenital group (CG) (n =36) had lower hearing thresholds and greater dynamic ranges than the non-congenital group (NG) (n = 71). Gap detection and temporal difference limen results were also significantly better in this group. The cochlear group (CO) (n = 15) had better hearing thresholds than reirocochlear (RC) (n=20). The sudden-onset (SN) (n = 14) group had worse dynamic ranges as compared to progressive group (PR) (n=22) but did better on gap detection and temporal difference limen. Dynamic ranges decreased with age in all groups.