51 research outputs found
Electrical vestibular stimulation in humans. A narrative review
Background: In patients with bilateral vestibulopathy, the
regular treatment options, such as medication, surgery, and/
or vestibular rehabilitation, do not always suffice. Therefore,
the focus in this field of vestibular research shifted to electri-
cal vestibular stimulation (EVS) and the development of a
system capable of artificially restoring the vestibular func-
tion. Key Message: Currently, three approaches are being
investigated: vestibular co-stimulation with a cochlear im-
plant (CI), EVS with a vestibular implant (VI), and galvanic
vestibular stimulation (GVS). All three applications show
promising results but due to conceptual differences and the
experimental state, a consensus on which application is the
most ideal for which type of patient is still missing. Summa-
ry: Vestibular co-stimulation with a CI is based on “spread of
excitation,” which is a phenomenon that occurs when the
currents from the CI spread to the surrounding structures
and stimulate them. It has been shown that CI activation can
indeed result in stimulation of the vestibular structures.
Therefore, the question was raised whether vestibular co-
stimulation can be functionally used in patients with bilat-
eral vestibulopathy. A more direct vestibular stimulation
method can be accomplished by implantation and activa-
tion of a VI. The concept of the VI is based on the technology
and principles of the CI. Different VI prototypes are currently
being evaluated regarding feasibility and functionality. So
far, all of them were capable of activating different types of
vestibular reflexes. A third stimulation method is GVS, which
requires the use of surface electrodes instead of an implant-
ed electrode array. However, as the currents are sent through
the skull from one mastoid to the other, GVS is rather unspe-
cific. It should be mentioned though, that the reported
spread of excitation in both CI and VI use also seems to in-
duce a more unspecific stimulation. Although all three ap-
plications of EVS were shown to be effective, it has yet to be
defined which option is more desirable based on applicabil-
ity and efficiency. It is possible and even likely that there is a
place for all three approaches, given the diversity of the pa-
tient population who serves to gain from such technologies
Cochlear erosion due to a facial nerve schwannoma
Facial nerve schwannomas are rare benign neoplasms. We report a case of a 60-year-old woman who initially presented with vestibular complaints. Magnetic resonance imaging (MRI) revealed a facial nerve schwannoma centered on the right geniculate ganglion extending in the labyrinthine segment. The patient consulted again after 2 months because she developed a sudden and severe right-sided sensorineural hearing loss. MRI showed no progression or pathological enhancement in the membranous labyrinth. A cone beam computed tomography (CT) of the temporal bone was performed and revealed a large erosion at the region of the geniculate ganglion in open communication with the middle turn of the cochlea. This case report demonstrates the importance of CT in facial nerve schwannomas for evaluating the impact on the surrounding structures
Electrical vestibular stimulation in humans: a narrative review
Background: In patients with bilateral vestibulopathy, the
regular treatment options, such as medication, surgery, and/
or vestibular rehabilitation, do not always suffice. Therefore,
the focus in this field of vestibular research shifted to electrical vestibular stimulation (EVS) and the development of a
system capable of artificially restoring the vestibular function. Key Message: Currently, three approaches are being
investigated: vestibular co-stimulation with a cochlear implant (CI), EVS with a vestibular implant (VI), and galvanic
vestibular stimulation (GVS). All three applications show
promising results but due to conceptual differences and the
experimental state, a consensus on which application is the
most ideal for which type of patient is still missing. Summary: Vestibular co-stimulation with a CI is based on “spread of
excitation,” which is a phenomenon that occurs when the
currents from the CI spread to the surrounding structures
and stimulate them. It has been shown that CI activation can
indeed result in stimulation of the vestibular structures.
Therefore, the question was raised whether vestibular costimulation can be functionally used in patients with bilateral vestibulopathy. A more direct vestibular stimulation
method can be accomplished by implantation and activation of a VI. The concept of the VI is based on the technology
and principles of the CI. Different VI prototypes are currently
being evaluated regarding feasibility and functionality. So
far, all of them were capable of activating different types of
vestibular reflexes. A third stimulation method is GVS, which
requires the use of surface electrodes instead of an implanted electrode array. However, as the currents are sent through
the skull from one mastoid to the other, GVS is rather unspecific. It should be mentioned though, that the reported
spread of excitation in both CI and VI use also seems to induce a more unspecific stimulation. Although all three applications of EVS were shown to be effective, it has yet to be
defined which option is more desirable based on applicability and efficiency. It is possible and even likely that there is a
place for all three approaches, given the diversity of the patient population who serves to gain from such technologies
Vestibular Infant Screening (VIS)–Flanders : results after 1.5 years of vestibular screening in hearing-impaired children
Due to the close anatomical relationship between the auditory and vestibular end organs, hearing-impaired children have a higher risk for vestibular dysfunction, which can affect their (motor) development. Unfortunately, vestibular dysfunction often goes unnoticed, as vestibular assessment in these children is not standard of care nowadays. To timely detect vestibular dysfunction, the Vestibular Infant Screening–Flanders (VIS–Flanders) project has implemented a basic vestibular screening test for hearing-impaired infants in Flanders (Belgium) with a participation rate of 86.7% during the first year and a half. The cervical Vestibular Evoked Myogenic Potentials (cVEMP) test was applied as vestibular screening tool to map the occurrence of vestibular (mainly saccular) dysfunction in this population. At the age of 6 months, 184 infants were screened. No refers on vestibular screening were observed in infants with permanent conductive hearing loss. In infants with permanent sensorineural hearing loss, a cVEMP refer rate of 9.5% was observed. Failure was significantly more common in infants with severe-profound compared to those with mild-moderate sensorineural hearing loss (risk ratio = 9.8). Since this is the first regional study with a large sample size and successful participation rate, the VIS–Flanders project aims to set an example for other regions worldwide
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