# Intralabyrinthine MRI FLAIR as a predictive marker for hearing loss in vestibular schwannomas in Neurofibromatosis Type 2

## TL;DR

This study shows that a specific MRI signal in the inner ear can predict hearing loss in patients with a genetic disorder called Neurofibromatosis Type 2.

## Contribution

The study introduces intralabyrinthine FLAIR MRI hyper-intensity as a novel predictive biomarker for hearing loss in NF2 patients with vestibular schwannomas.

## Key findings

- FLAIR hyper-intensity in the inner ear was strongly associated with future hearing loss in NF2 patients.
- Hearing loss occurred approximately 4 years after FLAIR signal changes in patients with normal hearing at baseline.
- Surgery stabilized hearing but did not reverse FLAIR hyper-intensity.

## Abstract

The onset of hearing loss due to vestibular schwannomas (VS) is inevitable but does not correlate with the size of the tumor. In patients with Neurofibromatosis Type 2 (NF2) and VS, we previously found an association between pre-contrast fluid-attenuated inversion recovery magnetic resonance imaging (FLAIR MRI) signal in the labyrinth and hearing loss. Here, we asked whether FLAIR hyper-intensity could serve as a predictive biomarker for hearing loss in NF2 patients with VS.

A prospective longitudinal study (NCT00598351) of NF2 enrolled 168 subjects between 2008 and 2013. This study included 34 patients with small VS (total volume ≤ 500mm3). Middle fossa decompression surgery (n = 4 patients) was provided via a standard-of-care trial (NCT00060541).

From 34 eligible subjects (mean age 26.8y) with NF2 and small VS, 53 ears met inclusion criteria. Abnormal hearing was recorded in 18 ears at study entry; all 18 ears had FLAIR hyper-intensity. Of the 35 ears with normal hearing, 16 had FLAIR hyper-intensity at study entry, 6 (37.5%) of which developed new hearing loss (median time to hearing loss of 4.45 years). Conversion to FLAIR hyper-intensity occurred in 11 ears, 3 of which proceeded to hearing loss. No hearing loss developed in the eight ears that remained FLAIR negative. FLAIR conversion has high sensitivity (1·00, 95% CI 0·39–1) and negative predictive value (1·00, 95% CI 0·63–1) for new-onset hearing loss. In 4 patients undergoing middle fossa decompression surgery, we found that surgery stabilized hearing but did not reverse FLAIR hyperintensity.

Our findings suggest that intralabyrinthine FLAIR hyper-intensity is a sensitive, non-invasive biomarker for hearing loss related to VS. Hearing decline followed FLAIR hyper-intensity by approximately 4 years but was absent in ears with normal FLAIR signal.

Registry: ClinicalTrials.gov, TRN: NCT00060541, Registration date: 4 June 2003.

The online version contains supplementary material available at 10.1007/s11060-026-05422-9.