Training your brain: Vestibular rehab for acoustic neuroma
Dizziness, vertigo, and imbalance are common symptoms of acoustic neuroma, also known as vestibular schwannoma, which is a benign tumour of the nerve that supplies the inner ear.
Elizabeth Crawford presented a webinar to members of the Acoustic Neuroma Association of Canada on the role of vestibular rehabilitation in helping symptoms of vestibular schwannoma.
Watch Elizabeth’s talk here:
Read the highlights from this talk:
Vestibular rehab & neuroplasticity
Vestibular rehabilitation is an exercise based treatment delivered by specially trained physiotherapists. It is an active program focused on improving problems caused by disorders of the vestibular system.
The vestibular system includes the balance organs of the inner ear that sense head movement and gravity, the vestibulocochlear nerve supplying the inner ear (cranial nerve VIII, where a vestibular schwannoma develops), and areas of the brain that process balance information (the cerebellum and the brainstem). Our vestibular system has connections to the muscles that move our eyes and the postural muscles in our bodies and neck that keep us upright. Our vestibular system is responsible for maintaining posture and balance, spatial orientation, and for gaze stability - allowing our vision to be clear and steady when our head is moving.
Our focus in vestibular rehab is to reduce symptoms of vertigo or dizziness, improve gaze stability, improve balance and mobility, and reduce risk of falls.
Vestibular rehabilitation exercises do not regenerate a damaged vestibular organ or nerve, instead our goal is to facilitate an adaptive response from the central nervous system - we are trying to train the brain. This occurs through neuroplasticity - our brain’s ability to make new connections and pathways. Vestibular rehab decreases symptoms and improves function by improving central compensation - changes in the brain to adapt to vestibular loss.
A vestibular schwannoma causes loss of the balance signals from the affected ear. If there is a sudden loss of signal from one ear this can cause vertigo - a false sense of movement that is often a spinning sensation, but can also be a feeling of rocking, swaying, or bobbing. When this loss happens gradually over time, the brain will adjust how it interprets the signals it is getting so you may not experience vertigo, but may instead have dizziness or feel off balance particularly when you are in motion or when you move your head.
If the balance signals from one ear are lost, our brain can adapt to the conflicting input it is getting from the two ears. Our cerebellum and brainstem are very important in this process. What stimulates this adaptation is exposure to movement - this allows our brain to recognize that it is getting incorrect signals and adjust how it interprets and responds to them. We are training the brain to recalibrate how it processes the signals and generates the eye movements and postural responses needed to keep us steady.
If you completely avoid movements that provoke symptoms, you will not compensate as well. For some people, the normal movements they do in day to day life are enough for this compensation process to occur. For others, particularly if they have had a very large or sudden loss of vestibular function, a specific program of vestibular rehabilitation exercises is needed to promote adaptation.
Is vestibular rehab effective?
Systematic reviews have concluded that there is moderate to strong research evidence (high quality randomized controlled trials) that vestibular rehab is a safe and effective treatment for loss of vestibular function. We also have a clinical practice guideline that provides recommendations to optimize outcomes.
What does vestibular therapy involve?
Your physiotherapist starts with a complete evaluation. We spend some time talking about your symptoms, health history, and goals. Then we do clinical tests of inner ear balance function and neurological function, and assess your balance and walking abilities.
Treatment is guided by the assessment findings and your priorities. Therapy sessions are active and exercise based, and tailored to your symptoms and goals. We create an individualized home exercise program for you to do every day. Two people with the same diagnosis may have very different home exercise programs, since these are customized to your particular needs.
There are three major categories of vestibular rehab exercises:
Gaze stability exercises > These exercises help train our brain to fine tune the vestibulo-ocular reflex (VOR). Our VOR requires our ears, eyes, and brain to work together to keep our vision stable while we move. These exercises involve keeping your eyes focused on a target while you move your head. It is important to do these exercises correctly to get maximum benefit from them - they don’t retrain your brain as effectively if you do them at too fast or too slow a speed. Neuroplastic change takes time and repetition, so these exercises are less effective if not done for long enough or frequently enough.
Balance exercises > These exercises are focused on improving your balance by training efficient and effective postural balance responses. These exercises need to be safe but challenging. If balance exercises are too easy, they are not going to stimulate an adaptive response. These exercises might include different foot positions, head movements, closing your eyes, standing on an unstable surface, or more dynamic challenges like walking while turning your head.
Habituation exercises > These are designed to gradually build tolerance to movements or environments that provoke symptoms of dizziness, for example bending down or walking in a busy place. These are customized to your level of tolerance and to the movements that trigger your symptoms.
Your treatment plan might also include exercises for leg strength, joint mobility, and a walking program. We may also give you suggestions on how to reduce your risk of falling or strategies to help cope with symptoms.
Since the vestibulocochlear nerve is close to the facial nerve, a vestibular schwannoma can cause facial muscle weakness if it presses on the facial nerve. Many vestibular rehabilitation physiotherapists also have expertise in facial neuromuscular retraining. If your vestibular schwannoma is causing changes in how your face moves (due to weakness or synkinesis), your physiotherapist can assess this and provide exercises as part of your program.
When can vestibular rehab help with acoustic neuroma symptoms?
A vestibular physio may be able to help you if you have problems with dizziness or balance across any stage of diagnosis or management of vestibular schwannoma.
During watch & wait or pre-treatment > If you are taking a watch & wait approach or are awaiting surgery or radiation, vestibular rehab can address symptoms of dizziness, and help maintain and improve your functional mobility and balance. We can also help you maintain and increase your physical activity levels, as being physically active pre-surgery is associated with better balance compensation post-surgery. Vestibular rehab can teach you balance and gaze stability exercises both to address any current symptoms and also exercises that you can perform post-treatment.
Post-surgery > After surgery, there is some research that suggests gaze stability exercises can speed up vestibular compensation, improve your balance, and help you feel less unsteady more quickly. After surgery, vestibular rehab can help with symptoms of dizziness or imbalance, improve your functional mobility, and help you get back to your usual activities.
Post-radiation > Dizziness, vertigo, and balance issues can occur at a delay after radiation treatment. For some people it can take up to 2 years for vestibular function to stabilize after radiotherapy. If you had vestibular symptoms before gamma knife you may be more likely to experience acute vestibular symptoms within 6 months post-gamma knife radiotherapy. If you are experiencing dizziness or balance problems after radiation, vestibular rehab can help facilitate better compensation, improve your balance and mobility, and help you get back to your usual activities.
Can I just do exercises on my own?
There are many resources available online that give instructions on vestibular rehab exercises. Doing exercises on your own can help as movement is key to maintaining and improving your balance abilities. Generally staying physically active is important. Exercises that involve moving your head and eyes, and safely challenging your balance can also be helpful.
However, seeing an experienced vestibular physiotherapist will give you a program that is customized to your particular challenges and goals. A physiotherapist with expertise in vestibular rehab can check that the exercises you are doing are effective - it is important you are performing exercises correctly and at the right level of challenge to get optimal results. There are also other factors that can contribute to balance problems - like muscle weakness and joint pain - and a physiotherapist can help evaluate and treat these issues.
Even if you have found a set of exercises to do on your own, it might be worth having a few sessions with a vestibular physiotherapist to see if you can optimize your program, and to learn how to progress your exercises as your abilities improve.
It can also be helpful to have a physiotherapist on your team to check in with when you need to, as your symptoms and balance abilities can change over time with acoustic neuroma.
Not sure if vestibular rehab could help your symptoms? Call us to speak to one of our physiotherapists!
For resources and support for people with acoustic neuroma, visit the Acoustic Neuroma Association of Canada.
Thumbnail image source: commons.wikimedia.org
