OBJECTIVE: To develop a radiologic classification of severity of round window involvement in otosclerosis and describe the impact of each class on hearing and outcome of stapes surgery. STUDY DESIGN: Retrospective chart review with radiologic review of computed tomographic scans. SETTING: Hospital and private otolaryngology clinics. PATIENTS: We reviewed computed tomographic scans of 930 ears with clinical otosclerosis; 121 (13%) had round window involvement, with no pericochlear involvement in 41 of these-the primary subjects of the study. A control group consisted of 15 ears with stapedial otosclerosis. MAIN OUTCOME MEASURES: Round window involvement was classified into 5 groups from isolated round window edge hypodensity (RW-I) to overgrowing obliteration with possible extension to the cochlea (RW-V). Hearing measures included 4-frequency pure-tone average air conduction, bone conduction, and air-bone gap (ABG). RESULTS: Of the 41 ears, 17.1%, 31.7%, 34.1%, and 17.1% were classified as RW-I to RW-IV, respectively. Patients with RW-I and RW-II otosclerosis, compared with the controls, showed no statistically significant differences in preoperative hearing or in ABG after stapes surgery. Patients with RW-III otosclerosis had significantly poorer hearing and a larger postoperative ABG (mean, 15 dB) than controls and groups RW-I and RW-II, whereas the RW-IV group showed the most severe hearing loss and poorest surgical outcome (all p's ≤ 0.001). CONCLUSION: The proposed classification for round window otosclerosis is a valuable clinical tool that can help in decisions regarding, and counseling about, stapes surgery. Classes RW-I and RW-II have no clinical impact. Patients with RW-III otosclerosis may have a mild residual gap after surgery; those with RW-IV have dramatically poorer results.
OBJECTIVE: To develop a radiologic classification of severity of round window involvement in otosclerosis and describe the impact of each class on hearing and outcome of stapes surgery. STUDY DESIGN: Retrospective chart review with radiologic review of computed tomographic scans. SETTING: Hospital and private otolaryngology clinics. PATIENTS: We reviewed computed tomographic scans of 930 ears with clinical otosclerosis; 121 (13%) had round window involvement, with no pericochlear involvement in 41 of these-the primary subjects of the study. A control group consisted of 15 ears with stapedial otosclerosis. MAIN OUTCOME MEASURES: Round window involvement was classified into 5 groups from isolated round window edge hypodensity (RW-I) to overgrowing obliteration with possible extension to the cochlea (RW-V). Hearing measures included 4-frequency pure-tone average air conduction, bone conduction, and air-bone gap (ABG). RESULTS: Of the 41 ears, 17.1%, 31.7%, 34.1%, and 17.1% were classified as RW-I to RW-IV, respectively. Patients with RW-I and RW-II otosclerosis, compared with the controls, showed no statistically significant differences in preoperative hearing or in ABG after stapes surgery. Patients with RW-III otosclerosis had significantly poorer hearing and a larger postoperative ABG (mean, 15 dB) than controls and groups RW-I and RW-II, whereas the RW-IV group showed the most severe hearing loss and poorest surgical outcome (all p's ≤ 0.001). CONCLUSION: The proposed classification for round window otosclerosis is a valuable clinical tool that can help in decisions regarding, and counseling about, stapes surgery. Classes RW-I and RW-II have no clinical impact. Patients with RW-III otosclerosis may have a mild residual gap after surgery; those with RW-IV have dramatically poorer results.
Authors: N Sanghan; T Chansakul; E D Kozin; A F Juliano; H D Curtin; K L Reinshagen Journal: AJNR Am J Neuroradiol Date: 2018-11-22 Impact factor: 3.825