The most common peripheral vestibular disorders that are treated by VRT are benign paroxysmal positional vertigo (BPPV), and any injury or disease that results in a reduced inner ear function. This reduced function may be associated with disorders such as Ménière’s disease, vestibular labyrinthitis or neuritis, or an acoustic neuroma. The term unilateral or bilateral vestibular hypofunction may be used in describing the reduced function of the vestibular system in one (unilateral) or both (bilateral) ears due to disease or injury.
Clinically, any peripheral dysfunction in the vestibular system, which affects one’s balance can potentially be treated with VRT, however the effectiveness of the treatment will depend on the exact cause of the vestibular issues.
Central vestibular disorders such as Multiple Sclerosis or stroke may also respond to VRT, although generally peripheral vestibular disorders tend to respond better.
Benign Paroxysmal Positional Vertigo (BPPV)
BPPV is a common clinical disorder of balance, which is characterized by recurrent vertigo spells that are brief in nature (usually 10-60 seconds) and are most often triggered by certain head positions. Benign, in medical terms, means it is not threatening to life. Paroxysmal means it comes with a rapid and sudden onset or increase in symptoms.
BPPV is the most common cause of recurrent vertigo. The cause of BPPV is proposed to be calcium carbonate crystals (termed otoconia, otoliths, canaliths or ‘ear rocks’) within the semicircular canals of the inner ear. In normal circumstances these crystals are located within the utricle and saccule of the ear but in BPPV it is thought that these crystals dislodge and migrate to the semicircular canals of the ear. The cause of this dislodgement is postulated to be a number of possible reasons such as an ear or head injury, an ear infection or surgery, or from natural degeneration of the inner ear structures. Often, however, a direct cause cannot be identified.
The otoconia settle in one spot in the canal when the head is still. The most common canal for settlement is in the posterior semicircular canal. A sudden change in head position, often brought on by activities such as rolling over in bed, getting out of bed, bending over, or looking upwards, causes the crystals to shift. This shift in turn sends false signals to the brain about equilibrium, and triggers the vertigo.
Vertigo due to BPPV can be severe and accompanied by nausea. The attacks can occur seemingly for no reason and then disappear for weeks or months before returning again. Generally BPPV affects only one ear and although it can occur at any age it is often seen in patients over the age of 60 and more often in women. Nystagmus is usually present.
Meniere's Disease
Meniere's disease is a chronic incurable vestibular disorder characterized by symptoms of episodic severe vertigo, fluctuating hearing loss, ear ‘fullness’ and/or ringing in the ear (tinnitus), and nystagmus.
This disease derives its name from a French Physician, Prosper Meniere, who theorized in the late 1800’s about the cause of this repertoire of symptoms, which he noted in many of his patients.
The exact cause of Meniere’s disease is still not certain but it is theorized that it is due to an abnormal amount of endolymph fluid collecting in the inner ear and/or an abnormal buildup of potassium in the inner ear.
Early-stage acute attacks of Meniere’s disease vary in their length anywhere from 20 minutes to 24 hours. The attacks can occur regularly within a week or may be separated by weeks or months. Other symptoms may coincide with the attack such as anxiety, diarrhea, trembling, blurry vision, nausea and vomiting, cold sweats, and a rapid pulse or heart palpitations. Following the attacks patients often feel extreme tiredness, which requires many hours of rest to recover. For some patients time between attacks may be symptom free but other patients report ongoing related symptoms even between attacks.
Vestibular Labyrinthitis or Neuronitis
Vestibular labyrinthitis or neuronitis is an inflammation of the inner ear or its associated nerve (the vestibular portion of the vestibulocochlear nerve), which causes vertigo. Hearing may also be affected if the inflammation also affects the cochlear portion of the nerve.
The vertigo caused by vestibular neuronitis or labyrinthitis is of a sudden onset and can be mild or extremely severe. Nausea, vomiting, unsteadiness, decreased concentration, nystagmus and impaired vision may also occur. Most often the infections that cause inflammation of the inner ear or the vestibulocochlear nerve are viral in nature as opposed to bacterial. Proper diagnosis in regards to it being viral or bacterial is important in order to provide the most effective and appropriate treatment.
Acoustic Neuroma
An acoustic neuroma is a benign (non-cancerous) tumour on the vestibulocochlear nerve. Early symptoms are related to loss of hearing in the affected ear, ringing in the ear (tinnitus), dizziness, and a feeling of fullness in the ear. The tumour is slow growing so symptoms come on gradually and may be easily overlooked in the early stages. As the tumour grows it may push on other nerves in the area and symptoms such as headaches or pain and numbness in the face may appear. Vertigo or other balance issues may arise with growth of the tumour.
