The semicircular canals
and their neural elements are derived from the two prominences of the otocyst, the horizontal and vertical canal pouches.
Patients are sequentially moved through a series of head position changes where gravity is used to move free-floating particles through the posterior semicircular canal
into the vestibule.
To the Editor: Semicircular canal
(SCC) malformation (dystrophy, coloboma, or enlargement) is a kind of inner ear anomaly.
The function of the horizontal semicircular canal
(CSH) was studied by means of response to caloric and rotatory stimulus, and the saccular function was examined using Vestibular Evoked Myogenic Potential (VEMP) in children with CI.
In an animal experiment, Angelaki et al reported that after they had plugged the horizontal semicircular canals
of rhesus monkeys, recovery of VOR gain and phase in response to yaw rotation was frequency-dependent; recovery was greatest at the highest frequency tested and it progressively diminished at the lower frequencies.
However, there are many systems, apart from the semicircular canals
, controlling eye movements .
(27.) Singh NK, Apeksha K Efficacy of cervical and ocular vestibular-evoked myogenic potentials in evaluation of benign paroxysmal positional vertigo of posterior semicircular canal
. Eur Arch Otorhinolaryngol.
These malformations included sclerotic cochlea as a sequela of meningitis (n=6), Mondini deformity (n=3), cochlea dysplasia (n=3), LVAS (n=3), large internal auditory canal (n=2), semicircular canal
aplasia (n=1), and semicircular canal
The caloric test is the most widely used test to assess the function of the semicircular canals
. Although the stimulation applied in the caloric test is not physiological, it enables the evaluation of both labyrinths separately (1).
The posterior semicircular canal
on the right was the culprit in 14 cases (73.7%), left side in remaining 5 cases (26.3%).
CT findings include ossification within the middle ear structures, including the membranous labyrinth, semicircular canals
Radiological signs indicating cholesteatoma in the attic included erosion or destruction of scutum or spur (the lateral wall of the attic), widening of the aditus ad antrum (loss of figure of "8" appearance) , antral wall erosions and widening , ossicular erosions and destruction , medial attic wall erosion which may lead to facial nerve canal involvement, which may cause paresis or paralysis , erosion of the lateral semicircular canal
which may result into fistula formation (Figure 1), dehiscence of tegmen tympani , dehiscence of sigmoid sinus plate, erosion of the external auditory canal (EAC), and automastoidectomy.