Pressure Testing for Superior Canal Dehiscence Syndrome
Alternative Title
Video 6.10 Evaluating for pressure-induced nystagmus from Neuro-Ophthalmology and Neuro-Otology Textbook
Creator
Tony Brune, DO; Daniel R. Gold, DO
Affiliation
(TB) Department of Neurology, The Johns Hopkins School of Medicine, Baltimore, Maryland; (DRG) Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine, Baltimore, Maryland
Subject
Valsalva; Superior Canal Dehiscence Syndrome
Description
𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: Superior semicircular canal dehiscence syndrome (SCDS) is caused by a third mobile window in the inner ear. This allows for transmission of sound or pressure to the superior canal. Tragal compression and/or glottic and pinched nose Valsalva may provoke vertigo and vertical-torsional nystagmus in the plane of the superior (anterior) canal. As an example, a patient with right SCDS may have downbeat-torsional (towards right ear) nystagmus provoked by pinched nose Valsalva, which is an excitatory pattern of nystagmus (see video, https://collections.lib.utah.edu/details?id=1213443). Nystagmus and vertigo are also commonly triggered by loud environmental noises, or provoked by loud tones in the clinic. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: Superior canal dehiscence syndrome (SCDS) is caused by a third mobile window in the inner ear. This allows for transmission of sound or pressure to the superior canal. Tragal compression and/or glottic and pinched nose Valsalva may provoke vertigo and vertical-torsional nystagmus in the plane of the superior (anterior) canal. As an example, a patient with right SCDS may have downbeat-torsional (toward right ear) nystagmus provoked by pinched nose Valsalva, which is an excitatory pattern of nystagmus. Nystagmus and vertigo are also commonly triggered by loud environmental noises, or provoked by loud tones in the clinic https://collections.lib.utah.edu/details?id=1307322. (Video and legend created with the assistance of Dr. Tony Brune and Justin Bosley)
