title: Case report: two cases of hearing impairment due to intracranial hypotension.
abstract: We report two cases of spontaneous intracranial hypotension (SIH) that presented with orthostatic hearing impairment. Pure tone audiometry in case 1 and distortion-produced otoacoustic emissions (DPOAEs) in case 2 clearly revealed orthostatic low-frequency hearing impairment. The symptoms resolved with conservative therapy in case 1, but they did not resolve completely after three treatments with epidural blood patch in case 2. The orthostatic changes at low-frequency that were present in both examinations indicated a relative endolymphatic hydrops due to SIH. Both otological examinations were useful to infer the pathophysiology of hearing impairment associated with SIH.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. taki@koto.kpu-m.ac.jp
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Taki
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Nin
authors.forename: Tatsuhisa
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sakaguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hisa
mesh_terms: D000328:Adult; D001301:Audiometry, Pure-Tone; D003051:Cochlea / Q000503:physiopathology; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D007022:Hypotension / Q000150:complications*; D020896:Hypovolemia / Q000134:cerebrospinal fluid; D011187:Posture; D012720:Severity of Illness Index