VS of the intracanalicular type might simultaneously compress the SVN and IVN via a scissor-like hold between the tumor and the IAC wall, resulting in a disturbance of both the
vestibular nerves.[sup][17]
The absence of brainstem involvement suggests that the lesion is limited to the
vestibular nerve. It is helpful to think of vestibular neuronitis as being a mononeuropathy, although this finding has not been confirmed.
The reduction in the number of hair cells is paralleled by a degeneration of the
vestibular nerve fibres which transmit vestibular information to the VNC in the brainstem (Engstrom, Bergstrom & Rosenhall, 1974).
There was absence of o-VEMPs on the tumor side with positive contralateral o-VEMPs in 37% of the cases, indicating superior
vestibular nerve (SVN) affection on the lesioned side.
(8) Vestibulocochlear schwannomas usually originate in the
vestibular nerve, but in some cases they arise from the cochlear nerve, as did the lesion in our patient.
Vestibular evoked myogenic potentials (VEMPs) help evaluate the function of the utricule and saccule as well as the superior and inferior
vestibular nerves. VEMPs are the reflexes rising as a response obtained through the sternocleidomastoid and orbital muscles due to high intense acoustic stimuli.
The findings share similarities with the expression data published by Caye-Thomasen et al., who included 16 sVS and compared them to three normal
vestibular nerves. Seventy-five genes were up-regulated, and three were down-regulated.
The tumor was situated on the superior
vestibular nerve, which was sacrificed in favor of complete resection of the tumor.
To summarize, they are the use of the operating microscope, tympanoplasty and mastoidectomy techniques, stapes surgery, endolymphatic sac surgery for intractable Meniere's disease, skull base surgery (for example, removal of vestibular schwannomas,
vestibular nerve sections), use of intratympanic gentamycin, and cochlear implantation, not to mention the discovery of new diseases.
The origin of cVEMP is thought to be the ipsilateral saccular macula, and the responsible neural pathway passes through the inferior
vestibular nerve to the vestibular nuclei, which includes the afferent limb of the sacculocollic reflex.
There should be interesting research possibilities for applying nanotechnology to some particularly challenging otolaryngologic problems, such as restoration of cochlear hair cells, regeneration of acoustic or
vestibular nerve fibers, treatment of tinnitus, and treatment of anosmia, among others.
Innervation of utricule is provided by superior
vestibular nerve which also collects impulses from lateral and superior semicircular canals.