Vestibular [ve-stib-yuh-ler] rehabilitation (VR), also known as vestibular rehabilitation therapy (VRT), is a specialized form of physical therapy used to treat vestibular disorders or symptoms, characterized by dizziness, vertigo, and trouble with balance, posture, and vision. These primary symptoms can result in secondary symptoms such as nausea, fatigue, and lack of concentration.
The term ‘vestibular’ refers to the inner ear system with its fluid-filled canals that allow for balance and spatial orientation. Some common vestibular disorders include vestibular neuritis, Ménière’s disease, and nerve compression. The most common vestibular disorder is Benign Paroxysmal Positional Vertigo (BPPV). Vestibular dysfunction can exist unilaterally, affecting only one side of the body, or bilaterally, affecting both sides.
BPPV is characterized by temporary dizziness feeling associated with blurred vision in relation to certain head positions. BPPV may affects anterior, posterior or horizontal vestibular canals. Posterior canal was reported in the literature as the most commonly affected canal, 80% of the patients diagnosed with BPPV. Several positional tests such as Hall-bike dix test, supine roll test, and head shaking nystagmus test may indicate which canal is affected by BPPV.
Vestibular damage is often irreparable and symptoms are persistent. Although the body naturally compensates for vestibular dysfunction (as it does for the dysfunction or deficiency of any sense), vestibular rehabilitation furthers the compensation process to decrease both primary and secondary symptoms.
In cases of chronic vestibular dysfunction, medication in the form of vestibular suppressants does not allow the nervous system to undergo compensation. Thus, long-term medication is not a viable option for individuals with chronic vestibular dysfunction. Because of this, vestibular rehabilitation therapy is a better alternative for long-term vestibular dysfunction. However, some medications, such as anticholinergics, antihistamines, and benzodiazepines, are useful in acute cases (of 5 days or less) for reducing nausea and other secondary symptoms.
Vestibular disorders can be diagnosed using several different kinds of assessments, some of which include examination of an individual’s ability to maintain posture, balance, and head position. The caloric reflex test is designed to test the function of the vestibular system and can determine the cause of vestibular symptoms. The reflex test consists of pouring water into the external auditory canal of a patient and observing nystagmus, or involuntary eye movement. With normal vestibular function, the temperature of the water has an effect on the direction of eye movement. In individuals with peripheral unilateral vestibular hypofunction, nystagmus is absent.
In some cases, the results of vestibular tests are normal, yet the patient experiences vestibular symptoms, especially balance issues and dangerous falls. Some diagnoses that result in non-vestibular dizziness are concussions, Parkinson’s disease, cerebellar ataxia, normal-pressure hydrocephalus, leukoaraiosis, progressive supranuclear palsy, and large-fiber peripheral neuropathy.
There are also several disorders known as chronic situation-related dizziness disorders. For example, phobic postural vertigo (PPV) occurs when an individual with obsessive-compulsive characteristics experiences a sense of imbalance, despite the absence of balance issues. Chronic subjective dizziness (CSD) is a similar condition characterized by persistent vertigo, hypersensitivity to motion stimuli, and difficulty with precise visual tasks. Both phobic postural vertigo and chronic subjective dizziness may be treated with vestibular rehabilitation therapy or other therapeutic methods such as cognitive behavioral therapy and conditioning.
Vestibular rehabilitation is specific to the dysfunction that a patient experiences. Some treatment methods seek to eliminate the cause of vestibular dysfunction, while others allow the brain to compensate for dysfunction without targeting the source. The former goal is for treating benign paroxysmal positional vertigo, while the latter treats vestibular hypofunction, which cannot be cured. The treatment process should begin as early as possible, to decrease fall risk. The patient should start slowly, gradually increasing the intensity and duration of exercises, and be accompanied by an accessible and reassuring therapist, as discomfort and negative emotional states can negatively affect treatment.
Treatment of benign paroxysmal positional vertigo (BBPV) depends on the canals involved (horizontal or vertical) and which form of BBPV the patient is experiencing (canalithiasis versus cupulolithiasis). Canalithiasis is characterized by a dislodged otolith particle, called otoconia, that floats in the fluid in one of the three vestibular canals and cause the feeling of dizziness with vision disturbances. On the other hand, cupulolithiasis is another form of BPPV caused by an attachment of otolith particle in the cupula (the base of semicircular canal) of the involved canal.
Canalith repositioning treatments (CRT) aim to move debris in the inner ear out of the semicircular canal in order to treat benign paroxysmal positional vertigo. CRT has five key elements: premedication of the patient, specific positions, timing of shifts between positions, use of vibration, and post-maneuver instructions.
Vestibular hypofunction can be a unilateral or bilateral vestibular loss. There are three types of vestibular rehabilitation exercises to reduce symptoms in cases where physical dysfunction cannot be reduced. The category of exercises chosen by a vestibular therapist depends on the problems reported by the patient. The following exercises can be used to treat dizziness with fast movements or exposure to intense visual stimuli, difficulty seeing (appearance of bouncing or jumping visual field) with head movement, and trouble with balance.
Habituation exercise aims to repeatedly expose patients to stimuli that provoke dizziness, such as certain motions and harsh visual stimuli. The provoking stimulus will induce dizziness at first, but with continued habituation exercises, the brain can adapt to discount the stimulus and dizziness reduces. As this occurs, the exercises can increase in intensity. The patient should take breaks between exercises when symptoms are experienced, until the symptoms stop.
Gaze stabilization exercises aim to increase visual ability during head movement. The goal of the patient during these exercises is to maintain the gaze during head movement. One kind of gaze stabilization exercise involves looking at a target and moving the head back and forth, without looking away from the target. Another exercise requires looking from one target to another, first without moving the head, and then moving the head to be aligned with the target without shifting the eyes. The last exercise for gaze stabilization is known as the remembered-target exercise and is performed partially with the eyes closed. First, the patient looks at a target object directly in front of them. Next, the patient closes their eyes and turns their head and turns it back. When the patient opens their eyes, they should still be looking at the target object.
Balance-training exercises (also known as postural-stabilization exercises) are designed to improve a patient’s ability to stay upright, and reduce the likelihood of dangerous falls. Balance-training exercises can be done walking or standing and can incorporate head movements and habituation exercises to limit exacerbation of symptoms. Increased postural stability can be achieved using visual and somatosensory cues. Thus, exercises in this category challenge the body’s use of these cues by limiting or changing them. For example, having the patient close their eyes limits their ability to rely on visual cues to maintain postural stability, while having the patient stand on foam alters their reliance on somatosensory signals.
The limitations of vestibular rehabilitation therapy are the overall health and function of the nervous system, especially the brainstem, cerebellum, and visual and somatosensory centers. The ultimate goal of vestibular rehabilitation therapy is reduction of vertigo, dizziness, gaze instability, poor balance, and dangerous falls; in some cases this goal is achieved without reducing dysfunction.
Other factors that determine the effectiveness of vestibular rehabilitation are behavioral ones, such as patient compliance to home exercises and limitations in daily life; the severity of the disorder (including unilateral versus bilateral dysfunction); the mental-emotional state of the patient, and other medical conditions and medications. 80 to 85 percent of patients with chronic vestibular disability reported a reduction in symptoms after VR.
The Daily Omnivore 