When patient II1 got to be 7 months, the CT and MR revealed a neurological maldevelopment of bilateral cochlear nerves
. The relationship between the cochlear nerves
abnormality and hearing loss is still not clear.
The prognostic relevance of cochlear nerve size on cochlear implantation is currently not well-established.
Several other studies reported conflicting data between sensorineural hearing loss (SNHL) and cochlear nerve size.
This may not represent the functional outcome with CI, which is closely related to the situation of the cochlear nerve. If there is cochlear nerve deficiency, this will have a negative influence on the audiological and speech and language developmental after implantation.
The cochlear aperture (CA) (bony canal for cochlear nerve) is the central bony passage at the base of the modiolus transmitting the cochlear nerve and blood vessels.
Previous studies [sup],, have proven that the RS approach has various advantages, such as the adequate control of bleeding, dissection of the entire tumor under direct view, easy identification of the facial and cochlear nerves at their root entry zone and the distal end in the internal auditory canal, and adequate exposure of the foramen of Luschka.
The right cochlear nerve (VIII) was subsequently cut under intraoperative neuromonitoring.
The motion of fluid in the cochlea stimulates hair cells in the Organ of Corti which, in turn, generate action potentials that are transmitted via the cochlear nerve through the central auditory pathway to the auditory cortex.
Lesions in the CPA-IAC can compress the cochlear nerve as it travels from the brainstem to the cochlea resulting in SNHL.
In our case, we verified the integrity of the cochlear nerves with electrocochleography.
Further, the modiolus could not be visualised, suggesting incomplete partitioning resulting in confluency between the middle and apical segments (Figure-1 a) Magnetic resonance imaging (MRI) showed intact cochlear nerve (Figure-1 b).
The toddler was born completely deaf in both ears -- without a cochlear (hearing portion of the inner ear) and a cochlear nerve.
He said medically the absence of a cochlear and cochlear nerve is referred to as cochlear aplasia.
One child with severe inner ear malformation i.e., Michel's deformity with hypoplastic cochlear nerve
on the left side, and Mondini deformity on right side, was excluded.
The fluid filled cochlea and the cochlear nerve
are the structures of highest interest for a successful surgery .