Superior semicircular canal dehiscence syndrome: Diagnostic criteria consensus document of the committee for the classification of vestibular disorders of the Bárány Society

Abstract

This paper describes the diagnostic criteria for superior semicircular canal dehiscence syndrome (SCDS) as put forth by the classification committee of the Bárány Society. In addition to the presence of a dehiscence of the superior semicircular canal on high resolution imaging, patients diagnosed with SCDS must also have symptoms and physiological tests that are both consistent with the pathophysiology of a ‘third mobile window’ syndrome and not better accounted for by another vestibular disease or disorder. The diagnosis of SCDS therefore requires a combination of A) at least one symptom consistent with SCDS and attributable to ‘third mobile window’ pathophysiology including 1) hyperacusis to bone conducted sound, 2) sound-induced vertigo and/or oscillopsia time-locked to the stimulus, 3) pressure-induced vertigo and/or oscillopsia time-locked to the stimulus, or 4) pulsatile tinnitus; B) at least 1 physiologic test or sign indicating that a ‘third mobile window’ is transmitting pressure including 1) eye movements in the plane of the affected superior semicircular canal when sound or pressure is applied to the affected ear, 2) low-frequency negative bone conduction thresholds on pure tone audiometry, or 3) enhanced vestibular-evoked myogenic potential (VEMP) responses (low cervical VEMP thresholds or elevated ocular VEMP amplitudes); and C) high resolution CT imaging with multiplanar reconstruction in the plane of the superior semicircular canal consistent with a dehiscence. Thus, patients who meet at least one criterion in each of the three major diagnostic categories (symptoms, physiologic tests, and imaging) are considered to have SCDS.

Proposal for a Unitary Anatomo-Clinical and Radiological Classification of Third Mobile Window Abnormalities

“…High-resolution CT (GE GSI Revolution, GE Healthcare, USA) of the petrous bone was performed in all patients. Slices were acquired helically in the axial plane at a nominal thickness of 0.625 mm with a 50% overlap of 0.312 mm, as recommended ( 27 – 29 ). Images were obtained in ultra-high resolution at 140 kV and 200 mAs/section.…”

Buegangsdehiscens

“…Det er nylig publisert diagnostiske kriterier for buegangsdehiscens basert på et internasjonalt konsensusarbeid (2). Klinisk sikker diagnose krever radiologisk dehiscens på CT av tinningben, minst e av fire karakteristiske symptomer og minst e av tre karakteristiske objektive funn.…”

“…Hos pasienter med u alte symptomer tilbys vanligvis kirurgisk behandling (2). Målet med kirurgi er å redusere de sykdomsspesifikke symptomene, og de e gjøres vanligvis ved å dekke over eller okkludere (plugge) den øvre buegangen.…”

“…Det ble vist at en defekt i den øvre buegangen i det indre øret kunne gi svimmelhetsanfall utløst av trykk og lyder samt overfølsomhet for benledet lyd. Sykdommen er uvanlig, men erfaringen er økende i Norge og internasjonalt, og det er nylig publisert internasjonale diagnostiske kriterier (2). Denne artikkelen er basert på forfa ernes egne kliniske erfaringer og ikke-systematiske li eratursøk i PubMed.…”

History Taking in Non-Acute Vestibular Symptoms: A 4-Step Approach

“…History taking is a crucial aspect in the diagnostic process for vestibular disorders [1], given that symptomatology plays a key role in the diagnostic criteria [2][3][4][5][6][7][8][9][10][11][12][13]. If history taking is done properly, in combination with physical examination, a diagnosis can be made in many cases, even without additional laboratory tests or imaging.…”