vestibular rehabilitation

How Can Vestibular Rehabilitation Help Me?

joanne — Fri, 09 Apr 2021 20:54:00 +0000

How Can Vestibular Rehabilitation Help Me? joanne Fri, 04/09/2021 - 16:54

Vestibular Rehabilitation is an exercise-based approach for treating people with dizziness and balance disorders that originated in the 1940’s. Since then there have been many advances in the assessment and treatment approaches for inner ear disorders. The inner ear is housed deep in the mastoid process behind the ear and it cannot be viewed with the otoscope. The key to assessment of the inner ear is by watching the eyes through special goggles that the patient wears. Eye movements when the head is stationary or moving will indicate what conditions are or are not present.

Some of the inner ear conditions that cause dizziness or balance disorders include Unilateral Vestibular Hypofunction (UVH), Bilateral Vestibular Hypofunction (BVH), Benign Paroxysmal Positional Vertigo (BPPV), Meniere’s Disease, Perilymph Fistulas and Acoustic Neuromas. This slow-growing tumour deep within the inner ear along the acoustic nerve causes a gradual loss of function of the inner ear, usually on one side of the head only. When one inner ear is sending less information to the brain than the opposite ear sends, the result is conflicting signals that the brain is trying to sort out and which, in my opinion, is the cause of the sensation called ‘dizziness’.

Dizziness is not a diagnosis, but a symptom that something is wrong, and it alone does not describe what a person might be experiencing. The meaning of ‘dizziness’ can be different for each person. Some people say they are dizzy when they are feeling off balance, unsteady, light-headedness, spinning, nausea, woozy, rocking and many other descriptions. And dizziness can be from many different causes other than the inner ear, including visual loss, sensory loss, mixed sensory losses, disease processes, neurological, psychological, pharmaceutical, and musculoskeletal systems. The neck may also cause dizziness, and this is called cervico-genic dizziness.

Treatment of the inner ear involves several different approaches and is individualized depending on the assessment findings:

Adaptation which involves retraining of the eye-head coordination so that the vision will be stable when the head is moving.
Habituation to improve tolerance to head movements.
Balance retraining for fall prevention and overall improved function
Substitution exercises for the body to learn to rely on the intact sensory systems when one or more of the other ones are not functioning.
Neck rehabilitation if needed for cervico-genic dizziness
Maneuvers to treat BPPV
Education and reassurance

Pre-AN Diagnosis and Pre-AN Surgery

Some of the early signs of an AN include dizziness and imbalance for which the person might seek an assessment by a Physical Therapist or Vestibular Therapist. During the assessment, there may be indicators of AN that the therapist may bring to the attention of the physician. Vestibular treatment at this point may help with the brain to learn to compensate for the loss of function, to retrain balance control and to improve the eye-head coordination. Before surgery is indicated, the person may already have complete loss of the vestibular function on the one side, and their brain may have already compensated for the loss, meaning that they have minimal balance concerns and minimal to no dizziness. If there is partial compensation, then they may be having ongoing difficulties.

Post AN Surgery

Following the surgical removal of the AN, the level of symptoms will be determined by the level of loss they had before surgery. As mentioned above, if there is complete loss then the post-surgical symptoms will be minimized, and the person should be able to return to full function fairly easily. If the loss was not complete prior to the surgery, then they will be experiencing a sudden loss of function and will have more difficulties and will require more vestibular therapy.

Can I have more than one condition at the same time?

It has been both my professional and personal experience that people can have more than one condition happening at the same time. This makes the diagnosis more complicated but a systematic and thorough assessment would help discern what is involved. In my years of experience, I found that the neck is a key component for many people and some simple exercises and stretches can make a tremendous improvement for the cervicogenic dizziness. People can also have unilateral vestibular loss and BPPV which again can be seen with a complete assessment and both can be treated effectively. As well people may have weakness in their lower body or loss of sensation in the feet, which will affect their balance. Anxiety in any of these conditions will, in my opinion, magnify the symptoms they are feeling and may limit their willingness to participate in the rehabilitation process.

Who should I see?

After seeing your doctor to rule out any medical concerns that may be contributing to your symptoms, an assessment by a “Vestibular Therapist” would be of benefit. Vestibular therapists typically have a background in Physical Therapy, Occupational Therapy, Audiology, or medicine (ENT). There are various levels of training from one or two-day weekend courses to more intensive 5-day training in Canada and the US. As well, the level of prior experience or training the therapist has will vary. Some courses have a competency process of testing the practical skills and written knowledge and some don’t. There is no set standard of entry level practice for vestibular rehabilitation, but in my opinion, a vestibular assessment that does not use the goggles will be not be complete.

I wish everyone with AN to have a dizzy free and balanced life!

Robynne Smith,
B.Sc.P.T., B.Sc.Anat

About the Author

Robynne’s post-graduate training includes advanced course work in Vestibular Rehabilitation in Canada and the USA. Additionally, she has completed FallProof training, which provides her excellent fall prevention skills. She also has experience and training in orthopedics, neurology, paediatrics, arthritic conditions (including osteoporosis) and chronic pain.

Robynne who ironically was treated for an acoustic neuroma in 2011 has specialized in balance and dizziness concerns including: vestibular neuritis, BPPV, BPV, Vertigo, imbalance, unsteadiness, cervicogenic dizziness, Meniere’s, and other inner ear concerns.

Assisting clients in restoring their balance allows them to return to previous activities of daily living without dizziness and fear of falling. Robynne is now offering professional training on Vestibular Rehabilitation for allied health professionals through introductory to advanced level seminars, workshops and courses. You can email her at saskbalance@sasktel. netwww.saskbalance.com

Managing Dizziness During A Pandemic: Rehabilitate While You Isolate!

admin — Wed, 08 Jul 2020 16:43:30 +0000

Managing Dizziness During A Pandemic: Rehabilitate While You Isolate! admin Wed, 07/08/2020 - 12:43

These are challenging times for most of us. Covid-19 results in altered routines, social isolation, changes to anxiety and depression, and fewer opportunities to meet with the health care providers that we rely on. These factors are especially magnified when you suffer from vestibular impairment. As a certified vestibular physiotherapist in Toronto, I am keenly aware of the struggles that patients have been grappling with these past few months. I’ve provided some tips to help you manage your dizziness and even reduce your dysfunction while you isolate at home.

If you’re reading this, you’re likely already aware of the effects that an acoustic neuroma has on your vestibular system. The pressure that this benign growth can assert on your vestibular nerve (part of your 8th cranial nerve) can produce a wide range of symptoms, and potentially leave you with a mild to severe disability.

These vestibular symptoms can include: dizziness, poor balance, motion sensitivity, difficulty focusing while your head is moving. Patients are often unable to live their lives as they’ve done before, affecting their ability to participate in physical activities, work at their jobs, and interact with their family and friends.

VESTIBULAR EXERCISES at HOME

Many patients with vestibular symptoms related to a schwannoma have already been assessed and received treatment from a vestibular physiotherapist. This means you’ll have a home exercise prescription that is specifically created for your unique presentation and modified to fit your recovery pattern.

However, many of you haven’t seen a professional or perhaps the coronavirus has made your rehabilitation appointments difficult to keep. To help you manage, I’ve provided some exercises you can try at home that may help. These don’t require fancy equipment and are generally safe for most vestibular conditions. Please note that vestibular rehabilitation is not a one size fits all solution, and best outcomes require a detailed assessment and skilled follow up visits with an experienced health professional.

1. Gaze Stabilization (Vestibular-Ocular Reflex)

Gaze Stabilization

This exercise addresses a core and basic vestibular function. Ensuring your eyes stay focused where you want them when your head moves or is repositioned.

Print or cut out a letter A (about 1cm in height) and tape it to the wall so it is at head level when you are seated.
Sit in a chair about arm’s length away from the letter A.
Keep your eyes glued to the letter A, while turning your head left and right. About 1⁄2 turn in both directions.
Repeat for 2 minutes

2. Standing Balance

Standing balance

Balance, and our sense of where our head and body is in space, is another core vestibular function. This exercise acts as a foundation for our vestibular system, allowing us to feel grounded when performing most other motions and activities.

Stand with feet together in front of a picture on your wall, with a chair behind you (for safety)
Focus on something specific in the picture for 10 seconds
Close your eyes for 10 seconds while maintaining your balance
Repeat for 2 minutes

3. Ball Throwing and Tracking

Ball throwing & tracking

Our vestibular system allows us to track moving objects even while our head is in motion. When this function is impaired, you may experience difficulty with activities such as shopping or watching traffic as you’re trying to cross the street.

You’ll need a tennis ball or something similar
Stand up straight and throw the ball from one hand to the other.
Keep your eyes on the ball at ALL TIMES and let your head move with the ball, as well
As you get more comfortable, try to throw the ball higher
Repeat for 2 minutes

4. Walking with Head Turns

Head turn right

Head turn left

Your gait (walking pattern) is often affected by vestibular impairments, particularly in busy places such as in crowds or at the supermarket. Your vestibular system is responsible for much of the head, eye, trunk and limb coordination that is involved with the simple task of walking.

Start at the end of a long hallway or a part of your house where you can safely walk back and forth
With your head turned to the left, walk a few lengths of your hallway
Repeat with your head to the right
Finally try it with your head rotating right and left
Repeat for 2 minutes

GENERAL ADVICE

Exercises and Activities

Dizziness is produced when your vestibular system experiences an error in the perception of movement. Generally speaking, the more “errors” you experience, the faster your recovery. This means that you must experience controlled instances of dizziness to get better, faster. The vestibular home exercises I’ve outlined above should produce some mild dizziness (errors) which your brain will correct through compensation. This also means that trying to keep moving and participating in activities that make you a “little” dizzy will help! The worst thing you could do is avoid any motion that makes you dizzy or imbalanced.

Anxiety and Depression

The vestibular system and depression and anxiety have neurological links within our central nervous system. This means that symptoms related to these areas often appear together. This also means that the recovery of one of these systems depends on the positive functioning of the other system. Ensure that you are doing all you can to manage anxiety and depression, or better yet, ask your doctor for more resources to assist you.

Click for article on managing stress, anxiety and a chronic impairment.

https://cornerstonephysio.com/resources/chronic-pain-stress-anxiety-covid-19/

Healthy Eating and Drinking

It’s no secret that what we put into our bodies has an effect on how we heal. The pandemic has made healthy eating and drinking habits particularly difficult to sustain and can directly result in an exacerbation of symptoms. My top tips include:

Staying hydrated. Drink more water, less caffeine and alcohol.
Decrease dietary salt. Read nutritional labels and fewer shakes with that shaker.
Don’t let your blood sugar levels spike. Avoid have a high sugar food after a long fast (e.g. breakfast time!)

Virtual Vestibular Rehabilitation

Battling dizziness and imbalance on your own can be confusing, uncertain, and stressful. And getting help can be difficult when travelling to a clinic, or if leaving the safety of your home is questionable. At my Cornerstone Dizziness Clinic, many vestibular patients have benefitted from virtual or telehealth rehabilitation to connect with a physiotherapist from the comfort of their homes. Learn more about whether this option may be right for you: https://cornerstonephysio.com/resources/can-virtual-physiotherapy-work-for-me

Joon Nah, BScPT

Joon Nah is a certified vestibular physiotherapist with credentials from the Emory School of Medicine and the University of Pittsburgh’s Dept. of Physical Therapy. As someone who has suffered from a chronic vestibular dysfunction himself, he founded the Cornerstone Dizziness Clinic in 2008.

vestibular rehabilitation

Hearing Rehabilitation in Patients with Vestibular Schwannomas

admin — Mon, 08 Apr 2019 20:59:24 +0000

Hearing Rehabilitation in Patients with Vestibular Schwannomas admin Mon, 04/08/2019 - 16:59

Vestibular schwannomas (a.k.a. acoustic neuromas) are slow-growing and benign tumours arising from the balance (vestibular) nerve. Most patients present with progressive symptoms of hearing loss, tinnitus, aural fullness, and imbalance. Over 90% of vestibular schwannomas are unilateral. Bilateral tumours almost exclusively occur in patients with Neurofibromatosis type 2 (NF2). Most patients with small and stable tumours can be observed. For larger or growing tumours, surgical resection or radiation are both effective in achieving tumour control. With any treatment strategy, patients are confronted with hearing loss and hearing rehabilitation in every stage of the disease is, therefore, an essential part of our treatment.

Hearing loss can be divided into two types: conductive hearing loss and sensorineural hearing loss. In a normal hearing ear, sound waves travel through the ear canal towards the eardrum. The eardrum and the middle ear bones (ossicles) transduce the sound energy to the hearing organ, the cochlea. In conductive hearing loss, sound waves are hindered to reach the cochlea by either obstruction in the ear canal or conditions affecting the middle ear or ossicles. Hearing loss caused by conditions in the cochlea or the vestibulocochlear nerve results in sensorineural hearing loss.

With pure tone audiometry (hearing testing) we can differentiate between these two types of hearing loss. Auditory thresholds are assessed by presenting stimuli via headphones and bone oscillators. With the headphones the entire auditory pathway is assessed, while with the bone oscillators the sound energy is transmitted through the vibration of the skull directly to the cochlea, bypassing the middle ear and the ossicles. Combining these two thresholds gives us an impression of the degree and type of hearing loss, i.e. conductive, sensorineural or a combination of both. Besides the pure tone audiogram, we routinely also perform tests of speech discrimination or speech understanding.

In someone with a unilateral vestibular schwannoma, we typically see a sensorineural hearing loss in the affected ear and normal hearing thresholds in the other ear. An asymmetric sensorineural hearing loss on the audiogram is, therefore, one of the reasons to perform additional imaging or additional hearing testing (auditory brainstem response or ABR) to identify or exclude a vestibular schwannoma. In patients with sensorineural hearing loss due to conditions in the cochlea, like excessive noise exposure, the patient’s speech discrimination ability is usually retained. In the typical patient with a vestibular schwannoma, the speech discrimination is poorer than what is expected based on the hearing loss measured with the pure tone audiogram. The presence of the tumour on the vestibulocochlear nerve leads to a distortion of speech.

Expected Natural History of Hearing

The best hearing outcomes occur in patients who are able to have their tumours simply followed with serial MRI scans. In these people, the hearing will remain the best the longest. Unfortunately, over time the hearing can deteriorate, even if the tumour does not change in appearance on subsequent MRI scans. In whom the hearing will deteriorate and in whom it will not is not possible to predict at this time.

Radiation therapy can sometimes stop a tumour from growing and preserve residual hearing. This is particularly possible if the radiation can be directed at the tumour while avoiding the cochlea. Similarly, it is sometimes possible to surgically remove the tumour and preserve the residual hearing. This is somewhat dependent on the size and the location of the tumour, but predictable preservation of hearing even in small, ideally situated tumours is not possible. In no instance is the hearing improved with treatment of the tumour.

Hearing Rehabilitation

Rehabilitation of the patient’s hearing loss is important at every stage. Patients with a mild to moderately severe hearing loss in one ear might benefit from a hearing aid. This hearing aid will amplify the sound enhancing their hearing ability. However, patients with severe-to-profound hearing loss may expect little benefit from a hearing aid on their affected side. For these patients, a contralateral routing of signals (CROS) hearing aid might be a better option.

The CROS device consists of two hearing aids. On the affected side, the hearing device consists primarily of a microphone that picks up the sound and transmits the signal wirelessly to the receiver of a hearing aid placed on the better hearing ear. With this setup, the CROS hearing aid can pick up sound from the impaired ear and transmit it to the better hearing ear. This enables patients to hear sounds from their impaired side with their better hearing ear. A CROS hearing aid can improve hearing ability especially in a quiet environment, but not all users experience these benefits, and some have difficulties integrating the sounds from both sides. As this process takes time and is different for every individual user, a thorough trial period with a CROS device is therefore advised before committing to purchase.

A different, but more expensive option for patients with unilateral severe-to-profound hearing loss (single-sided deafness) is a bone conduction device (BCD) or bone anchored hearing aid (BAHA). This system consists of a titanium screw that is surgically fixated in the bone behind the ear, and an external bone oscillator which can be attached to the screw. The microphone, integrated into the bone oscillator, receives the sound signal. The sound processor converts this signal to an oscillation which is transmitted via the screw to the skull. The vibrating skull will activate the cochleae on both sides as they are embedded in the bone of the skull. In a patient with a unilateral severe hearing impairment due to a vestibular schwannoma, the impaired side is unable to adequately process these signals, but the vibrations are also registered by the cochlea on the normal hearing side resulting in activation of this cochlea. As with a CROS hearing aid, the BCD enables patients with unilateral hearing loss to hear sounds from their impaired side with their better hearing ear. The main difference is that the BCD uses vibration of the bone to activate the cochlea on the better hearing side, whereas the CROS hearing aid uses air conduction.

The CROS hearing aids and BCDs are only viable options for patients with a properly functioning contralateral ear. In patients with bilateral severe-to-profound sensorineural hearing loss caused by either a unilateral vestibular schwannoma and contralateral impaired cochlear functioning, or bilateral vestibular schwannomas, cochlear implants (CIs) and auditory brainstem implants (ABIs) are indicated.

A cochlear implant consists of an external sound processor and a surgically implanted device with an electrode array that is placed in the cochlea on the impaired side. The sound received by the sound processor is converted to an electrical signal which is directed through the electrode array. In the cochlea, the electric current activates nearby nerves resulting in activation of the nerve fibers which propagate this signal up to the brain. Although with vestibular schwannomas the problem is located behind the cochlea, in the vestibulocochlear nerve, cochlear implants are able to activate enough neural tissue to produce a signal, which can still be propagated through the nerve and past the tumour. Cochlear implantation in an ear with a vestibular schwannoma is mainly indicated for patients with bilateral tumours due to NF2. Because the tumour properties and extent are different in each patient, the hearing result of cochlear implantation in patients with a vestibular schwannoma is more variable than in traditional cochlear implant patients with hearing loss not due to a vestibular schwannoma.

If, despite cochlear implantation, patients do not fare well, or if the tumor is growing and requires surgical resection, an ABI might be indicated. Just like a CI, an ABI consists of an external sound processor and an internal device with an electrode array. However, this electrode array is not placed within the cochlea but instead is placed on the cochlear nucleus in the brainstem. The ABI enables patients to perceive sounds, even after surgical removal of the tumour and the vestibulocochlear nerve. However, the hearing result is in general poorer and more variable compared to cochlear implant users. Most ABI users are able to detect sounds and obtain measurable assistance with lip-reading, but a minority are able to gain significant speech understanding. Vancouver has recently been approved for an ABI program.

Conclusion

Hearing rehabilitation is an integral part of vestibular schwannoma treatment. Given the variation in hearing impairment among patients and the progressive nature of the hearing loss, an individually tailored approach is required in every stage of the disease. We advise patients to talk with their audiologists and ENT surgeons about all different rehabilitation options to aid them in their current situation and in their future.

Article by Dr. Marc Lammers, Dr. Emily Young, Dr. Jane Lea, Dr. Brian Westerberg

BC Rotary Hearing and Balance Centre, Division of Otolaryngology, St. Paul’s Hospital, University of British Columbia.

Dr. Brian Westerberg, specializing in Otology and Neurotology is based at the B.C. Rotary Hearing and Balance Centre in Vancouver. He completed a Fellowship at Stanford University and a Masters in Health Care and Epidemiology at the University of British Columbia (UBC) and has served the Royal College of Physicians and Surgeons as Program Director, and member of the Examination Committee and Chair of the Specialty Committee in OHNS at UBC.

Dr. Westerberg's interest in global health is apparent in his involvement in Zimbabwe and Uganda Hearing Health Care Programs. He is a clinical professor in the Department of Surgery and Director of the Branch for International Surgical Care at UBC.

therapy

vestibular rehabilitation

Trekking to the 2018 Symposium: Elizabeth’s Pathway to Managing Her AN

joanne — Tue, 05 Mar 2019 22:17:50 +0000

Trekking to the 2018 Symposium: Elizabeth’s Pathway to Managing Her AN joanne Tue, 03/05/2019 - 17:17

Elizabeth Ewashkiw from Belleville, Ontario has been working hard to minimize her symptoms with the help of a vestibular therapist.

Elizabeth Ewashkiw

As an active, 74-year-old retired kindergarten teacher, I consider myself an engaged member of the community. Medically, I have keratoconus which is a progressive eye disease in which the normally round cornea thins and begins to bulge into a cone-like shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina causing distorted vision, for which I have had three corneal transplants over the past 40-plus years culminating in an unsuccessful trabeculectomy for glaucoma. This has left me with no vision in one eye and a scleral lens in the other.

Having gradually adjusted to the lack of depth perception and minor balance issues, I was therefore not surprised when I seemed to develop vertigo a few years ago. I was careful getting into boats (we cottage on an island, so this is significant), started holding hand rails when possible, and got on with life.

In January 2018 after my flight home from BC, I experienced sudden onset deafness in one ear and secured an appointment with our ENT in Belleville. Also, after the flight to Europe in May 2018, I had balance issues and needed to take my husband's arm for the whole trip. The vertigo gradually settled down somewhat after we were home again.

After waiting for an appointment, waiting for an audiogram, waiting to have my ear cleaned out, taking time to cottage in the summer, and having an MRI, I was eventually diagnosed at the end of August 2018 with a small acoustic neuroma. It was not until November, when I had a second audiogram, that I was referred to Dr. Joseph Chen at Sunnybrook Health Sciences in Toronto.

My way of coping with the unknown is to learn all I can, so I turned to the search engines on the Internet looking for recognized national sites about acoustic neuromas. I soon learned that there was an acoustic neuroma association in Canada and, lo and behold, they would be holding a national symposium in Toronto at the end of September.

Living two hours away, I registered for the live webcast of the 2018 Symposium and sent a note. I immediately received a phone call from Carole Humphries, whose knowledgeable, warm and supportive manner, was exactly what I needed. Carole encouraged me to come to Toronto to experience the conference in person. The networking around our table, the fourteen pages of notes I took, the fact that the room was full of people with my symptoms, including some who had had surgery, plus the presenters making themselves available for brief chats during our refreshment breaks made this an invaluable day. I was able to introduce myself to Dr. Chen as a probable new patient and he immediately told me to discard the cane, use walking poles, and start walking, looking left and right continuously.

Elizabeth walking as part of her rehabilitation

I gathered later that this was to help my brain adapt to receiving balance information from my one set of circular canals, rather than the usual two.

The conference also gave me the opportunity to speak to a vestibular therapist whose expertise I realized I needed.

Arriving home in full-blown overload, I emailed my physiotherapist and the manager/friend of the clinic I had used in the past. I learned that my present therapist was also qualified in vestibular therapy. I started immediately, as I continued the twice-a-week free VON seniors' exercise classes, which contain a balance component. Homework for the therapy became mandatory as I practised walking a straight line, gradually moving my arms, and eventually I expect to be able to change elevation and focus (by bending knees, raising heels, rotating shoulders, etc.). This is only one of the multitude of exercises I have learned in recent months. If I neglect to maintain them, my balance is compromised. The rewards are built in. If I work at it, I experience success. If not, . . .? I get right back to practising!

By mid November 2018, I had an appointment with Dr. Chen, who reassured me that my small (0.6 x 1.5 cm) neuroma only needs monitoring every couple of years with an MRI, which I can have done in my home town of Belleville.

I have "graduated" from vestibular therapy but am most welcome to return when I deem it necessary and will continue to participate in two VON one-hour classes per week.

I had also learned about the CROS hearing aids when at the ANAC conference. Messages from the deaf ear are transmitted wirelessly to the functioning ear, from which the info is sent to the brain. When home, I went to learn about hearing aids. After another audiogram I asked what would be appropriate for me. The answer was the CROS. These I received on December 4. I certainly hear more with them (they look just like any other hearing aids, i.e. inconspicuous), but I do get caught out by the lack of directionality. If in a crowded room I hear a voice calling my name, I must rotate, checking people's facial expressions, to tell who has spoken to me! Similarly, around a table of unfamiliar people at a meeting, I don't automatically know who spoke. It all just adds another layer to "paying attention" to make it all work.

Presently I don't have to explain to people that I have balance issues or hearing in one ear only because I've learned how to compensate as much as possible. This is my new normal and it's working for me.

Understanding Vertigo in Vestibular Schwannomas

admin — Fri, 06 Apr 2018 21:52:51 +0000

Understanding Vertigo in Vestibular Schwannomas admin Fri, 04/06/2018 - 17:52

A Quality of Life Issue

The cardinal symptoms of vestibular schwannoma are unilateral hearing loss, tinnitus, vertigo, and unsteadiness. Most patients present with unilateral hearing loss (94%) and tinnitus (83%). Vestibular symptoms such as spinning vertigo, nausea, disequilibrium and imbalance have often been reported as mild, but are nevertheless present in 40 to 75% of patients. There is however remarkable variability in vertigo symptom severity and impact among patients. Several factors could explain this variability including the size of the tumour, the rate of growth, the rate of vestibular loss and the patients’ overall premorbid functioning level.

Recent studies focusing on quality of life associated with vestibular schwannoma have shown that when present, vertigo is the most debilitating and distressing symptom with respect to health-related quality of life. It also constitutes a risk factor for future work disability. While the subjective extent of impairment by vertigo is quite low initially, it could change considerably after intervention (surgery or radiation).

Why is there vertigo?

As humans, we orient ourselves in space with the input of our senses (vision, proprioception and vestibular function) integrated at the level of our central nervous system. The differential diagnosis of dizziness is therefore very broad.

The general complaint of «dizziness» is divided into four subtypes with different underlying etiologies: vertigo, disequilibrium, presyncope and psychological dizziness. Vertigo is a false sensation of movement of oneself or the environment. Disequilibrium is a sense of postural imbalance associated with a loss of balance that can relate to issues with the musculoskeletal system and proprioception. Presyncope is a feeling of faintness while psychological dizziness is typically related to anxiety or mood disorders. Vertigo can originate from a peripheral or central unilateral, asymmetric impairment of the vestibular system that causes an illusory sensation of movement.

The peripheral vestibular apparatus includes three semicircular canals, the utricle, saccule and the vestibular nerves. The central vestibular system comprises the vestibular nuclei, the brainstem, spinal cord, vestibular cortex and the cerebellum.

The role of the vestibular system is to help us maintain stable vision when the head is moving (through the vestibulocular reflex (VOR)) and to contribute to maintaining posture (through the vestibulospinal (VSR) and vestibulocolic reflexes (VCR)).

In the context of vestibular schwannoma, the tumour growth on one of the vestibular nerves affects the function of that nerve thus generating the asymmetry. It means that the vestibular reflexes (VOR, VSR and VCR) are impaired. Although acute changes of vestibular function can occur with vestibular schwannoma thus generating vertigo attacks with nausea, vomiting, lateropulsion to the lesioned side, and nystagmus to the contralesional side, the clear majority evolve so slowly that the changes of vestibular function are very subtle, and most patients do not experience severe a acks of vertigo. Vertigo is the presenting symptoms of only 10-15% of all vestibular schwannoma. More commonly, the patients with vestibular schwannoma might report symptoms of blurry vision for a split second when moving their head quickly toward the side of the lesion which is a sign of impaired VOR. They can also report a vague sense of imbalance and dizziness. Reports suggest that up to 75% of patients with vestibular schwannoma have some degree of vestibular symptoms.

As the tumor grows, it can put pressure on the brainstem and cerebellum thus generating more significant symptoms of dizziness and balance problems.

How does the approach to the management of vestibular schwannoma impact on vertigo?

The three commonly accepted treatment modalities for vestibular schwannoma include radiation therapy, microsurgery, and observation. Most studies comparing the different treatment approaches focus on comparing neurologic morbidity, hearing preservation and facial nerve function outcomes, all of which can be objectively assessed. Given that vertigo and dizziness are very subjective symptoms, the impact of treatment modalities on vertigo control is much more di cult to assess. A variety of scales and questionnaires have been designed to assess the extent and impact of vertigo (Dizziness Handicap Inventory (DHI, Vertigo Symptoms Scale (VSS), Short Form 36 Survey, Glasgow Benefit Inventory, etc.). None of these assessment tools is perfect as they all have their advantages and limitations. At the present time, while there is significant heterogeneity among small studies, there are no large-scale studies assessing vertigo symptoms systematically. It is therefore difficult to draw firm conclusions as to the impact of various treatment modalities on vertigo symptoms.

Smaller quality-of-life studies seem to suggest that surgery is associated with an increase in impairment of QOL by vertigo in the post-operative period. One study has shown that 31% of patients have disequilibrium lasting > 3 months after surgical removal of an acoustic neuroma. Worse outcomes were associated with age > 55.5 years, female gender, constant preoperative disequilibrium present for > 3.5 months, and central findings on electronystagmography.

Depending on the surgical approach, post-operative dizziness could be related to the extent of cerebellar retraction (retrosigmoid approach), and the loss of any residual vestibular function spared by the schwannoma. Because this change happens acutely at the time of surgery, vertigo is more readily perceived by the patient. Pre-operative vestibular function does impact the perceived dizziness after surgery. Therefore, someone who has had a slowly growing acoustic neuroma on one vestibular nerve and then has undergone surgical removal of the neuroma may exhibit almost no vestibular symptoms because the progressive and complete vestibular loss has already been compensated for progressively as the neuroma grew. By the time the surgery takes place, the patient has no effective vestibular function in the affected ear and the surgery could not worsen it further.

Because there is heterogeneity in the extent of vestibular function pre-operatively, there is a lot of variability among patients’ postoperative dizziness symptoms. Conversely, radiation therapy seems to be associated with lower rates of vestibular symptoms in the acute post-treatment period. Given that the impact of radiation can be felt for years after the treatment, some studies suggest an increase in dizziness in the years after treatment.

Treatment of Vertigo: What is vestibular physiotherapy and how does it work?

Regardless of the treatment approach to vestibular schwannoma, significant vertigo symptoms can be present and impact the patients’ quality of life. Specifically targeting these vertigo symptoms and overall balance is an important component of the care provided to patients with vestibular schwannoma. Given that regaining vestibular function on the tumor side is not possible, the therapeutic approach focuses mainly on optimizing compensation for this unilateral vestibular loss through vestibular physiotherapy.

Both animal and human studies emphasize the importance of early ambulation with head and neck mobilization in the first four post-operative days. Mobilization in this crucial period of recovery has a significant impact on the course of vestibular compensation. Encouragement and reassurance are needed at that time since patients might feel quite dizzy during this acute post-operative period and be very reluctant to move. Antiemetics and vestibular suppressants can be used to control nausea in this acute setting but should not be used long-term as they hinder the compensation process.

Vestibular compensation encompasses a variety of centrally mediated mechanisms that help us achieve vision and postural control despite the lack of vestibular input. At the level of the brainstem and cerebellum, the activity of the vestibular nuclei is modulated but the impact on maintaining the vestibular re exes is marginal. Compensation happens mainly through input substitution and learned anticipatory adjustments which can be trained.

The loss of vestibular function from one ear leads to increased reliance on vision and somatosensory information to perceive self-motion, orient the body, stabilize the head and control the center of mass. For instance, instead of the VOR, vision is stabilized though anticipated covert eye movements (saccades) that happen during the head movement.

Through a variety of exercises centered on stabilizing vision and maintaining balance while the head is moving, and the body is in motion, vestibular physiotherapy triggers the development of these alternative compensatory mechanisms. In the initial postoperative period, these exercises can feel as if they trigger the vertiginous symptoms because they bring out the vestibular deficit. This is the stimulus necessary for the brain to engage the compensatory mechanisms. With time and effort, desensitization to the symptoms and compensation occur while a more robust balance is achieved, all contributing to decreased vertigo and disequilibrium.

Dr Mijovic

Tamara Mijovic MD CM FRCSC is an assistant professor of Otolaryngology-Head and Neck Surgery at McGill University.

As a fellowship trained Otologist and Neurotologist, she is the director of the McGill University Health Center (MUHC) Vestibular Laboratory and an active lateral skull base surgeon part of the multidisciplinary Skull Base Surgery Team at the Jewish General Hospital.

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