We assessed the efficacy of the Epley maneuver (canalith repositioning) in a study of 81 patients with posterior semicircular canal
benign paroxysmal positional vertigo (BPPV).
A modified Epley maneuver was performed for all patients with posterior semicircular canal
BPPV, with a 98% success rate.
Abnormal symmetry occurs when there is a significant difference between the responses from each horizontal semicircular canal
Each of the semicircular canals
is positioned at a different angle and is especially sensitive to different movements: up and down, side-to-side, and tilting from one side to the other.
The vestibular part of the membranous labyrinth consists of three semicircular canals
as anterior, posterior, and horizontal, and two otoliths as utricle and saccule; the source of the calcium carbonate crystals (otoconia) that are responsible for BPPV is the macula of the saccule (4).
A diagnosis of posterior semicircular canal
BPPV is confirmed with a transient, upbeating, torsional nystagmus with the eyes beating toward the underlying ear when the patient is rapidly positioned into the lateral head-hanging position (Dix-Hallpike maneuver) (2).
If EAC cholesteatoma invades the mastoid cavity, it may damage the fallopian canal, semicircular canals
, and sigmoid sinus [3, 5, 6].
The caloric test is the most widely used test to assess the function of the semicircular canals
The pre-operative CT scans were reported to assess characteristic cholesteatoma findings, location and extension of soft tissues in middle ear, integrity of scutum, erosion of the ossicular chain, integrity of the thin bony septum of facial nerve canal, the semicircular canals
and the tegmenextension of cholesteatoma outside the middle ear, integrity of mastoid air cells, trabeculae, as well as relationship and proximity of soft tissues with the tympanic membrane were assessed.
Magnetic resonance imaging (MRI; figure, B) and computed tomography (CT; figure,C) of the temporal bone showed a mass with its epicenter on the posterior fossa plate, with extensive bony destruction of the semicircular canals
, focal erosion into the basal turn of the cochlea, and involvement of the jugular bulb.
Benign positional vertigo (BPV) is a common and correctable cause of episodic vertigo triggered by otoconia dislodged from the otolith membranes of the utricle into the semicircular canals
The inner ear consists of the cochlea, vestibule and semicircular canals
encased in the bony otic capsule.
A rotational component to vertigo makes it highly likely that there is a disorder of the semicircular canals
or their central pathways.
The vestibular apparatus is found in the inner ear, and consists of three fluid-filled semicircular canals
8) The vestibular system consists of five end organs: three semicircular canals
and two otolith organs.