Retrospective Review of MR Findings in Sudden Sensorineural Hearing Loss and Associated Clinical Features

BACKGROUND AND PURPOSE: Sudden sensorineural hearing loss (SSNHL) is a dramatic and often frightening condition that benefits from prompt treatment. While most cases of SSNHL are idiopathic, a retrocochlear pathology is expected to account for some presenting cases of SSNHL. This study aims to assess the presence of retrocochlear pathology in SSNHL and ascertain whether clinical features could help determine their presence on MRI.

MATERIALS AND METHODS: A retrospective cohort study was conducted using a patient data registry from 2015 to 2022. Patients who underwent MRI of the internal auditory canals for SSNHL at a single center were included. MRs were reviewed for relevant positive findings and incidental actionable findings. Clinical features recorded included laterality of hearing loss, tinnitus, dizziness, vertigo, and pure tone average (PTA) thresholds from audiograms. Treatment decisions were documented. Exclusion criteria included previous temporal bone pathology, trauma, surgery, or missed MR appointments.

RESULTS: Eight hundred forty-one patients (929 ears; mean age 53.6 years ±15.7 [standard deviation]) were included. MRs showed no retrocochlear pathology in 874 ears (94.1%). Twenty-five ears had relevant tumors (2.7%). Nine patients with tumors underwent surgery or radiation. All tumors were visible on noncontrast cisternographic sequences. Twenty-one ears (2.3%) had findings suggestive of labyrinthitis. Additional relevant findings included enlarged endolymphatic ducts and small cochlear nerves. Patients with a PTA ≥49.5 dB had 5.3 times higher odds of having a tumor or labyrinthitis on MRI (P < .001), and those with tinnitus had 4.2 times higher odds (P = .02). No statistical difference was found in steroid use between patients with or without labyrinthitis features (P = .38).

CONCLUSIONS: Most patients showed no retrocochlear pathology on MRI, with only 2.7% having relevant tumors. To screen for urgent pathology, a noncontrast MR protocol may be feasible. Clinical features such as high PTA values and tinnitus may increase the odds of finding a treatable retrocochlear condition.