Canal dehiscence.
OBJECTIVE
The aim is to review canal dehiscence involving the superior, lateral, and posterior semicircular canals. The main focus will be on superior semicircular canal dehiscence.


RESULTS
Canal dehiscence involving the superior, lateral, and posterior semicircular canal can have different etiologies, including developmental abnormality, congenital defect, chronic otitis media with cholesteatoma, and high-riding jugular bulb. However, their clinical presentation can be very similar, with patients complaining of vertigo, oscillopsia, and sometimes hearing loss. Canal dehiscence causes an abnormal communication between the inner ear and the surrounding structures. This creates a third mobile window within the inner ear, disrupting its normal mechanics and causing symptoms.


CONCLUSIONS
Superior semicircular canal dehiscence is now a well-established entity in the medical literature. Surgical repair is effective at relieving patients' vestibular symptoms. Lateral semicircular canal dehiscence is usually associated with chronic otitis media. Posterior semicircular canal dehiscence is a rare entity, with similar clinical presentations and treatment options as the other canal dehiscences.
Department of Otolaryngology-Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. wchien1@jhmi.edu
Wade W
WW
Chien
John P
JP
Carey
Lloyd B
LB
Minor
D004427:Ear Diseases / Q000150:complications / Q000209:etiology / Q000473:pathology*; D005133:Eye Movements / Q000502:physiology; D006314:Hearing Loss, Conductive / Q000209:etiology; D006801:Humans; D007762:Labyrinthitis / Q000150:complications; D012665:Semicircular Canals / Q000473:pathology*; D014717:Vertigo / Q000209:etiology; D014722:Vestibule, Labyrinth / Q000503:physiopathology