What is vestibular support?
The CHi multidisciplinary team provides vestibular support to patients with vestibular problems such as dizziness, vertigo and disequilibrium. Vestibular problems may present before or after implantation. It is important to remember that these problems can be managed very effectively.
What is the vestibular system?
The vestibular system is the system of the inner ear that helps to regulate balance. It is important for keeping images steady even when you move your head, as well as for balance control and spatial orientation. It consists of the peripheral vestribular organ situated in the inner ear itself, the vestibulocochlear nerve, and the central vestibular organ and neural connections situated in the brainstem.
The vestibular part of each inner ear consists of five different organs namely:
- The utricle
- The saccule
- The superior semi-circular canal
- The posterior semi-circular canal
- The lateral semi-circular canal
Vertigo after cochlear implantation.
Vertigo is not a condition, it is a symptom. It is the sensation that you feel when it seems as if the environment around you is moving when it shouldn’t be. Spinning or rotational vertigo is often the result of a vestibular disorder. You may experience vertigo either as individual attacks or spells, or it may manifest as a permanent or chronic disorder.
While vertigo may rarely occur after cochlear implantation surgery, it is usually a temporary condition. It may also occur after any of the other implantable hearing solutions, but this is extremely rare. In some cases, the vertigo may be due to the aggravation of a pre-existing vestibular disorder and often is totally unrelated to the implant.
The vestibular function in patients with implantable hearing solutions.
One should not overlook the fact that the vestibular and hearing organ of the inner ear is intimately related, not only in development but also in location. The vestibular organ and the cochlea share a common nerve, the vestibulocochlear nerve, that relays the sensory information to the brain. It is therefore not uncommon that conditions that affect the hearing also affects the vestibular function. Congenital infections will likely cause injury to both. Many of the acquired forms of hearing loss may be accompanied by a vestibular loss. Vestibular loss is not always detected as it may be greatly compensated for by other systems such as vison and the somatosensory system.
When a vestibular disorder is suspected, a referral to a CHi vestibular specialist may be necessary. A careful history and clinical examination will indicate whether diagnostic testing is warranted. The assessment includes a battery of tests, including videonystagmography (VNG), video head impulse testing (vHIT), cervical and ocular vestibular evoked myogenic potentials (cVEMP/oVEMP), electrocochleography (ECochG), VORTEQ autorotation testing, dynamic visual acuity (DVA) and gaze stabilisation testing (GST). Imaging may be necessary and x-rays and computed tomography (CT) scans can be performed without a problem after an implant. However, magnetic resonance imaging (MRI) is a problem after implantation and your doctor will carefully consider the pros and cons of sending you for a MRI, and ensure every precaution is taken to prevent harm to your implant if a MRI is deemed necessary. The latest cochlear implant systems can withstand some, but not all, MRIs.
The treatment of patients with vestibular disorders requires a multidisciplinary approach. The treatment depends on the specific condition. Post-implant patients who suffer with dizziness will be managed with in accordance with the procedure and device that was used in the implant surgery.
Patients who suffer from vestibular attacks due to other pathological conditions of the vestibular system may benefit from life style modifications, manoeuvres, medical therapy or surgery. Such conditions include Meniere’s disease and endolymphatic hydrops, vestibular neuritis, benign paroxysmal positional vertigo (BPPV), vestibular migraine and perilymph fistula.
Patients with loss of vestibular function or a weak vestibular organ may benefit from balance and vestibular rehabilitation. There are specialised therapists trained in vestibular rehabilitation who can help and who will develop a rehabilitation programme that is specifically tailored to the individual patient’s condition.