Posterior semicircular canal dehiscence syndrome

Posterior semicircular canal dehiscence syndrome (PSCD) is the presence of vestibuloauditory symptoms secondary to absence of the bony covering of the posterior semicircular canal (PSC).

Epidemiology

It is thought to be rare: in a case series of 112 patients with a high riding jugular bulb it was found in only four patients (~4%).

Clinical presentation

The main ascribed symptom is hearing impairment, with a broad spectrum of severity, from minor conductive loss to marked sensorineural deafness. The pathogenic reason for this remains unexplained.

Vertigo has been found in a number of cases of posterior semicircular canal dehiscence although a causal link remains contentious ¹.

Pathology

Etiology

Dehiscence of the posterior semicircular canal has been demonstrated in the imaging context of a high-riding jugular bulb and fibrous dysplasia ^1,2. 

Treatment and prognosis

Optimal management remains to be determined. Prognosis is unknown.

Related pathology

• superior semicircular canal dehiscence syndrome
• lateral semicircular canal dehiscence syndrome