Diagnosing perilymphatic fistula with 3D flair MRI

Abstract

Introduction: The diagnosis of a perilymphatic fistula (PLF) has long been a challenge, as its presentation is variable and can mimic other vestibular disorders. Currently, it is suggested that resolution of symptoms after treatment should be used as a gold standard in diagnosing PLF. Recently, improvement in Magnetic Resonance Imaging (MRI) have caused PLF to be diagnosed more consistently with a higher sensitivity and specificity, preceding surgery. Case report: We report a 43-year-old patient, who was seen with progressive vertigo since 15 years, triggered by bending forward, and lasting from 20 min to 2 h. During these spells, she would also have pulse-synchronous tinnitus and mild left-sided mixed hearing loss. Physical examination was normal and vestibular function tests did not reveal evidence of peripheral or central audiovestibular dysfunction. Delayed acquisition MRI, with 3-dimensional fluid attenuated inversion recovery (3D FLAIR) of the inner ear displayed a left ‘round window sign’ (RWS): focal enhancement in the round window niche. There were no signs of vestibular or cochlear hydrops to suggest Meniere’s syndrome. Her symptoms resolved after surgery. Conclusion: RWS on 3D FLAIR MRI sequence seems to be a sensitive and specific pre-operative diagnostic phenomenon for the detection of PLF.