RT Journal Article SR Electronic T1 Spectrum of Third Window Abnormalities: Semicircular Canal Dehiscence and Beyond JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 2 OP 9 DO 10.3174/ajnr.A4922 VO 38 IS 1 A1 Ho, M.-L. A1 Moonis, G. A1 Halpin, C.F. A1 Curtin, H.D. YR 2017 UL http://www.ajnr.org/content/38/1/2.abstract AB SUMMARY: Third window abnormalities are defects in the integrity of the bony structure of the inner ear, classically producing sound-/pressure-induced vertigo (Tullio and Hennebert signs) and/or a low-frequency air-bone gap by audiometry. Specific anatomic defects include semicircular canal dehiscence, perilabyrinthine fistula, enlarged vestibular aqueduct, dehiscence of the scala vestibuli side of the cochlea, X-linked stapes gusher, and bone dyscrasias. We discuss these various entities and provide key examples from our institutional teaching file with a discussion of symptomatology, temporal bone CT, audiometry, and vestibular-evoked myogenic potentials.EVASenlarged vestibular aqueduct syndromeSSCCDsuperior semicircular canal dehiscence