Diagnosing perilymphatic fistula with 3D flair MRI

IntroductionThe 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 reportWe 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.ConclusionRWS on 3D FLAIR MRI sequence seems to be a sensitive and specific pre-operative diagnostic phenomenon for the detection of PLF.