a1 Department of Otolaryngology, School of Medicine, Kangwon National University, Chunchon, South Korea
a2 Eaton-Peabody Laboratory, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, USA
a3 Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts, and the Neurology Service, Massachusetts General Hospital, Boston, Massachusetts, USA
a4 Department of Neurology, Harvard Medical School, Boston, Massachusetts, and the Neurology Service, Massachusetts General Hospital, Boston, Massachusetts, USA
Introduction: Superior semicircular canal dehiscence affects the auditory and vestibular systems due to a partial defect in the canal's bony wall. In most cases, sound- and pressure-induced vertigo are present, and are sometimes accompanied by pulse-synchronous tinnitus.
Case presentation: We describe a 50-year-old man with superior semicircular canal dehiscence whose only complaints were head rotation induced tinnitus and autophony. Head rotation in the plane of the right semicircular canal with an angular velocity exceeding 600°/second repeatedly induced a ‘cricket’ sound in the patient's right ear. High resolution temporal bone computed tomography changes, and an elevated umbo velocity, supported the diagnosis of superior semicircular canal dehiscence.
Conclusion: In addition to pulse-synchronous or continuous tinnitus, head rotation induced tinnitus can be the only presenting symptom of superior semicircular canal dehiscence without vestibular complaints. We suggest that, in our patient, the bony defect of the superior semicircular canal (‘third window’) might have enhanced the flow of inner ear fluid, possibly producing tinnitus.
(Accepted June 08 2009)
(Online publication September 29 2009)
c1 Address for correspondence: Dr Robert A Levine, Eaton-Peabody Laboratory, Massachusetts Eye & Ear Infirmary, 243 Charles Street, Boston, MA 02114-3096, USA. Fax: +1 2617 720 4408 E-mail: Robert_Levine@MEEI.harvard.edu
Dr R A Levine takes responsibility for the integrity of the content of the paper.
Competing interests: None declared