Reduced Cochlear MRI Signal and Hearing Outcomes in Conservatively Managed Vestibular Schwannoma Patients.

Objective: This study aimed to determine if hypointense cochlear magnetic resonance imaging (MRI) constructive interference in steady-state (CISS) signal correlates with hearing outcomes in conservatively managed vestibular schwannoma (VS) patients.

Study design: Retrospective review of 657 cases from 1992 to 2020.

Setting: Tertiary academic referral center.

Patients: A retrospective review was performed to identify conservatively managed VS patients with appropriate baseline MRI, audiology, and at least 12-month audiological follow-up. Patients were excluded if they progressed to surgery or radiotherapy in less than 12 months, bilateral tumors, or surgery on the contralateral ear.

Intervention: Conservatively managed patients with CISS imaging studies and audiology testing.

Main outcome measures: Primary outcome measure change in pure-tone average (PTA) and word recognition score (WRS). Secondary outcome measures tumor size, presence of lateral fluid cap, or cystic changes.

Results: A total of 92 individuals (47% male, 58 ± 11.6 yr) met the inclusion criteria, with 36 (39%) of patients demonstrating abnormal cochlear CISS signal. At baseline, abnormal cochlear CISS signal was associated with higher intracanalicular (IC) length (7.9 versus 6.6 mm, p = 0.0177) and lower WRS (55.7 versus 78.8 dBHL, p = 0.0054). During follow-up, individuals with abnormal cochlear CISS signal had significantly higher PTA (62.4 versus 46.4 dBHL, p = 0.0010). After adjusting for baseline covariates, abnormal cochlear CISS signal was consistently associated with a greater increase in PTA of 8.3 dBHL (95% confidence interval, 2.9-13.7; p = 0.0032) from baseline when compared with the normal group.

Conclusions: Abnormal cochlear signal on MRI CISS sequences is associated with poorer hearing outcomes in conservatively managed VS patients.