Case report: Two cases of hearing impairment due to intracranial hypotension Masakatsu Taki * , Fumiaki Nin, Tatsuhisa Hasegawa, Hirofumi Sakaguchi, Satoshi Yamamoto, Toshihiro Suzuki, Yasuo Hisa Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan Received 23 March 2008; accepted 30 May 2008 Available online 5 September 2008 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. # 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Spontaneous intracranial hypotension; Hearing impairment; Relative endolymphatic hydrops; DPOAE 1. Introduction Intracranial hypotension is typically manifested by postural headache (headache in the upright position, relieved by recumbency). It occurs as a result of low cerebrospinal fluid (CSF) volume caused by either spontaneous or post- traumatic dural laceration. It often associates with one or more of the following symptoms: nausea, vomiting, pain or tight feeling in the neck, dizziness, diplopia, photophobia, hearing impairment, and blurred vision [1,2]. Although hearing impairment is one of the most common associated symptoms, only a few reports have described the otological examinations for hearing impairment due to spontaneous intracranial hypotension (SIH) [3–6]. We report two cases with intracranial hypotension who presented orthostatic hearing impairment that were clearly demonstrated by pure tone audiometry and distortion-produced otoacoustic emis- sions (DPOAE). 2. Case report 2.1. Case 1 A previously healthy 29-year-old woman developed severe headache, vomiting and neck stiffness in September 2006. The headache worsened when she was sitting and was alleviated when she lay flat. She did not have a history of trauma, but had a history of yoga exercise. She was referred to the Department of Neurology and Gerontology of our hospital for further evaluation by another hospital and was hospitalized 6 days later. General physical examination was normal. Blood pressure was 81/64 mmHg and there were no meningeal signs. Neurological examination was normal. Head magnetic resonance imaging (MRI) (Fig. 1A and B) revealed a slight gadolinium enhancement of the dura mater. The decent of the www.elsevier.com/locate/anl Auris Nasus Larynx 36 (2009) 345–348 * Corresponding author. Tel.: +81 75 251 5603; fax: +81 75 251 5604. E-mail address: taki@koto.kpu-m.ac.jp (M. Taki). 0385-8146/$ – see front matter # 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.anl.2008.05.016