Vestibular Rehabilitation: Therapy for Dizziness/vertigo /balance dyfunction.
Our balance system is a complex and beautiful design. Sensory organs in our inner ear; the cochlea (shaped like a fiddle fern with tiny velvety hair sensors that detect where your head is in space) and the semicircular canals (that are like 3D levels that have viscous fluid that actually organize where your eyes are in space) are special organs that synchronize with our eyes, our neck and our body’s proprioceptive system to keep us upright.
When the vestibular organs are damaged with disease or injury, the brain can no longer rely on them for accurate information about equilibrium and motion, often resulting in dizziness, vertigo, balance problems, and other symptoms.
Many people are able to recover from these symptoms on their own after a few weeks of normal activity because the brain has adapted with a process called vestibular compensation. However, if the vestibular compensation process is not successful, a person’s ability to maintain posture and coordinate balance may become overly dependent on input from the eyes (vision) and muscles and joints (proprioception).
In addition, the person may develop new patterns of head and body movement in an attempt to avoid dizziness and nausea. For example, a person with a vestibular disorder might adopt an exaggerated hip sway as a method of balancing, swivel the entire body rather than just the head when turning to look at something, or always look down at the floor to avoid what appears to be a confusing swirl of activity.
Unfortunately, these strategies can make vestibular compensation even more difficult, worsening symptoms and often causing headache, muscle tension, and fatigue.
The goal of VRT is to retrain the brain to recognize and process signals from the vestibular system in coordination with vision and proprioception. This often involves desensitizing the balance system to movements that provoke symptoms.
What happens during VRT? A qualified Physiotherapist will first perform a thorough evaluation that begins with a medical history and includes observing and measuring posture, balance and gait, and compensatory strategies. The assessment may also include eye-head coordination tests that measure how well a person’s eyes track a moving object with or without head movement. Other assessments may be used, such as a questionnaire measuring the frequency and severity of symptoms and associated lifestyle changes.
Using the evaluation results, the therapist will develop an individualized treatment plan that includes specific head, body, and eye exercises to be performed both in the therapy setting and at home. These exercises are designed to retrain the brain to recognize and process signals from the vestibular system and coordinate them with information from vision and proprioception. This often involves desensitizing the balance system to movements that provoke symptoms.
WHERE IS THE PROBLEM? What is the Treatment? How can physiotherapy help?
BPPV (Benign Paroxysmal positional vertigo) is a condition where the experience of vertigo is due to canalithiasis or cupuloithiasis. The exact pathology is still under review, but it has to do with crystals that are in the inner ear system that rest on the hairs (endolymph in the canals) or tug the cupula (organ that detects linear acceleration and free fall descent) to give faulty information to the brain that the head is rotating…uncontrollably.
Treatment consists of specific manoeuvres to off load the crystal and restore the sensor. These include the Epley manouvre, Dix-Hallpike manoeuvre, Semont manoeuvre, Brandt-Daroff technique, Bar-B-Que roll or forced prolonged positioning. These treatments depend on which canal has the problem as they are on 3 different planes.
Special instructions are given post treatment to prevent re-occurrence.
Cervicogenic Dizziness is a condition where the neck has been injured either through Whiplash Associated disorders (WAD) or other circumstances that injure or mess up the kinestetic sensors (where your head is in space). These receptors lie in the muscles, joints and ligaments and give your brain information via the vestibular system (inner ear) as to where the head is in space. When these receptors are injured, a small movement in the neck can seem extreme to the eye and the brain and this ‘mismatch’ can give the experience of dizziness.
Treatment may include manual/manipulative therapy to ensure proper arthrokinematics of the spinal joint complex, specific neck exercises to strengthen the stabalizing muscles, kinesthetic/proprioceptive exercise to regain joint position sense(cervical repositioning) and eye exercise to regain the vestibular ocular reflex (VOR) control.
Peripheral Vestibular Nerve Dysfunction is any condition that causes a dysfunction in the vestibular system (bacterial, viral, trauma) that can cause a sensation of dizziness.
These can include
- Meniere’s disease
- Vestibular neuritis
- endolymphatic hydrops
- perilymphatic fistula
- acoustic neuroma
- labyrinthine concussion
- drug/environmental toxicity (ototoxicity)
- mal debarquement
- motion sensitivity
Treatment will include medical intervention for the root cause (antibiotics, antiviral medication, surgery), dietary changes to alleviate the cause. Dizziness that remains can be helped by habituation, adaptation, substitution and balance exercises. These are specific exercises for each deficit that can include eye exercise (Gaze stabilization).
Central Vestibular Nerve dysfunction is any condition that effects the central processing mechanisms for balance in the brain (Motor cortex, cerebellum) that can give the sensation of dizzziness or vertigo.
These can include:
- Stroke (vascular infarction to areas in the brain)
- traumatic head injury
- vertebrobasilar artery ischemia
- multiple sclerosis
- degenerative changes
Treatment can include medications, dietary changes and exercises specific for the condition.
These include adaptation, substution and habituation exercise for the vestibular ocular reflex system (VOR). These are aimed at vestibular compensation that can be incredibly plastic (able to recover after injury).