Bogengangsdysplasie

Incidence,

Phenotypic Features and Molecular Genetics of Kallmann Syndrome in Finland. The axial 3D T2-weighted MRI images from the region of the inner ear of (A) a KS patient with normal semicircular canals (asterisk), and (B) a KS patient with hypoplastic semicircular canals (arrow), and an unspecified atrophic area (arrow head) in his retina (C).

ojrd.biomedcentral.com • CC-by-2.0

Dysplasie des

horizontalen (lateralen) Bogengangs links (rechts im Bild) mehr als rechts. Links ist der Bogengang knöchern nicht mehr als Gang ausgebildet und vom Vestibulum nicht mehr abgegrenzt. Man erkennt dahinter den axialen Anschnitt des posterioren Bogengangs mit normalem Kaliber. Vergleiche .

Wikipedia • CC BY-SA 3.0

Neuroimaging

assessment in Down syndrome: a pictorial review. Temporal bone CT (a) and MRI (axial T2/3D) (b) from a 2-year-old patient with Down syndrome at the level of the internal auditory canal, showing complete absence of the right bone island and consequent aplasia of the lateral semi-circular canal. Note also the dysplastic vestibule as a result of the absence of the lateral semi-circular canal

insightsimaging.springeropen.com • CC-by-4.0

Neuroimaging

assessment in Down syndrome: a pictorial review. Temporal bone CT (a) and MRI (axial T2/3D) (b) from a 2-year-old Down syndrome patient at the level of the lateral semi-circular canal, revealing left hypoplastic bone island (less than 3 mm in greatest diameter). Axial temporal bone CT (c) at the same level of a normal 2-year-old boy for comparison

insightsimaging.springeropen.com • CC-by-4.0

Down syndrome

• Semicircular canal dysplasia - Ganzer Fall bei Radiopaedia

Akkary, E. Semicircular canal dysplasia. Case study, Radiopaedia.org. (accessed on 01 Nov 2022) https://doi.org/10.53347/rID-65424 • CC by-nc-sa 3.0 (modified)

Semicircular

canal dysplasia • Enlarged vestibular aqueduct syndrome - Ganzer Fall bei Radiopaedia

Bayat M, Enlarged vestibular aqueduct syndrome. Case study, Radiopaedia.org (Accessed on 21 Jul 2023) https://doi.org/10.53347/rID-76350 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

Semicircular canal dysplasia is relatively common of the labyrinthine anomalies. About 40% of patients with a malformed cochlea will have associated lateral semicircular canal (SCC) dysplasia . The other two common labyrinthine anomalies include SCC aplasia and SCC dehiscence.

Clinical presentation

In isolated SCC dysplasia, patients may have normal or near-normal hearing. However, if the cochlea is involved there may be sensorineural hearing loss. SCC dysplasia has also been associated with conductive hearing loss and vestibular symptoms .

Pathology

Lateral SCC dysplasia results from disordered embryological development in the sixth week of gestation. During this time, a bud forming the SCC will form a semicircular evagination from the vestibular anlage with the central part of the pocket-shaped protrusion which adheres centrally leaving a peripheral semicircular tube. SCC dysplasia results when failed central adhesion occurs. The lateral SCC is more often deformed in this process over the posterior or superior SCC because it forms later in embryogenesis .