HOW TO IMPROVE DIZZINESS WITH VESTIBULAR THERAPY FOR ACOUSTIC NEUROMA
I recently had the honor of researching the evidence and presenting on this very topic as a part of a panel discussion for the comprehensive management of Acoustic Neuroma for the American Academy of Otolaryngology-Head and Neck Surgery. So, do you need vestibular therapy for acoustic neuroma? The evidence says..YES!
What is Vestibular Rehab Therapy (VRT)?
Vestibular rehabilitation therapy (VRT) is an individualized exercise approach used to treat dizziness and balance deficits in patients with inner ear dysfunction. The exercise prescription can include a mix of activities targeted to address weakness in the inner ear or brain pathways of the vestibular complex.
Many studies point to the effectiveness of VRT in treatment of vestibular unilateral hypofunction for symptom resolution and improvement of function. Because the evidence points to VRT being so effective at treating one-sided inner ear weakness from conditions such as acute neuritis, one could assume the same would be true for hypofunction related to post-surgical resection of acoustic neuroma.
Surgical resection of acoustic neuroma causes a sudden unilateral loss of vestibular function similar to the rate of loss acquired through acute neuritis. The sudden loss of vestibular input through surgical resection typically produces intense vertigo, nausea, disequilibrium, oscillopsia, and unsteady balance & gait.
After resection, the initial severe symptoms of spontaneous symptoms, vertigo, and nausea typically subside in hours to days. However, dizziness and unsteadiness, especially with head movement can persist for weeks, months, or longer. Persistent symptoms can lead to fall and safety risks, economic impacts, inability to return to driving, working, and even relationship stress.
By implementing the use of VRT by a trained and knowledgeable vestibular therapist, we can promote faster central compensation of the surgical vestibular hypofunction and get patients back to feeling like themselves more quickly.
Treatment Approaches Used in VRT
1) Adaptation. With the purpose of improving the function of the VOR, vestibulo- ocular reflex. Adaptation exercises produce long-term nervous system changes that will allow the eye to maintain stability during head movement. Thus improving balance and reducing symptoms of dizziness or disorientation in movement, as one can now better maintain a stable focal point. Gaze stability exercises work by producing a quick mistake or slip of eye focus which is initiated by head movement that the brain can recognize and correct. Find an intro to VOR exercises here at my Custom Care Rehab youtube channel
2) Substitution. This treatment focuses on other body systems to counteract the loss of vestibular function. We can use ocular exercises all driven by the central nervous system such as anticipatory saccades, smooth pursuits, or corrective saccades. We can also substitute an increased somatosensory contribution through balance and postural correction exercises. When a patient has decreased vestibular function, grounding and body awareness can be particularly important if full vestibular compensation cannot be expected.
3) Habituation. This involves repeated exposure to a specific task or stimuli that provokes symptoms of dizziness in order to desensitize the patient's response to symptoms. Exercises are individualized and meant to produce only mild to moderate symptoms. The purpose is to progress exercises until the patient no longer experiences symptoms with the task.
4) Canalith Repositioning- which will only be used for patients identified with BPPV, Benign Paroxysmal Positional Vertigo. This technique would be reserved only for people identified with the condition if it were to be concurrent with acoustic neuroma.
Which Treatment Approach is Best?
Truly, treatment approaches should be selected depending on patient symptoms.
Findings in studies pertaining to introducing vestibular rehab after a surgical resection for acoustic neuroma showed the groups of patients performing the adaptation exercises had significantly:
Better static balance performance
Less subjective disequilibrium
Less staggering when walking and performing head turns; thus less fall risk
Reduced reported dizziness
Visual Blurring with head movement should be treated with gaze stability exercises. Adaptation exercises to maximize remaining vestibular function. Substitution exercises to promote use of alternative strategies to substitute for missing vestibular function. There is strong evidence that clinicians should not include voluntary eye movements in isolation without head movement as specific exercises for gaze stability. For example, prescribing only eye-tracking or shifting eyes to look at targets are not effective exercises for vestibular nerve weakness over the adaptation head-shaking exercises.
To treat dizziness and vertigo caused by specific stimuli or movement there is moderate evidence demonstrating that clinicians can use habituation exercises. These are designed to perform several repetitions of body movements or watch visual motions that cause mild to moderate symptoms. Can use visual stimuli or virtual reality scenarios for visual motion sensitivity.
Patients with balance and fall risk can be treated through substitution through promoting somatosensory improvements. May involve changes in base of support to increase balance challenge and weight shifting to improve center of gravity control. Gait exercises, may include varying the activities (eg, head turns, secondary tasks, optokinetic drums, virtual reality systems), to promote improvement of dynamic control.
Lastly, as evidence points to patients who are more active having better outcomes endurance and physical activity may be promoted. Walking or dynamic aerobic tasks can be promoted. Recumbent cycling and general conditioning, by themselves, have not been found to reduce patient complaints related to vestibular dysfunction.
When Should you Start your Vestibular Rehab Program?
One study examining benefits of VRT in resection was published by Susan Herdman et al. Vestibular adaptation exercises and recovery: Acute stage after acoustic neuroma resection. The study was small but demonstrated significant improvements in balance and reported dizziness between the group of patients who started gaze stability exercises in the hospital after surgery starting day 3 to post-op day 6. Exercises were performed 5 x a day for a maximum of 10-20 minutes a day. So patients could get clearance by the neurosurgery team and safely start therapeutic exercise as early as day 3 in the hospital. A trained vestibular therapist can give patients the appropriate instructions and modifications to make these exercises as comfortable and as therapeutic as necessary.
Individualized vestibular rehab for a person’s needs and tolerance, is more effective than strictly a protocol. However, research has shown both: protocols and individualized programs will give patients relief and function. A protocol in the inpatient setting may be appropriate and then transition to an individualized program in an outpatient setting where a person can discuss their particular symptoms with a vestibular therapist. Another option may be to include a “pre-surgery” Vestibular Therapy program, where the patient receives education on inpatient VRT exercise to perform after cleared by neurosurgery. You can find your local vestibular therapist HERE through VEDA and many therapists even offer telehealth for people who do not have local access to a vestibular specialist. Many hospitals have total joint education programs going into surgery so people know what to expect, so having a pre-surgical vestibular education program would only make sense. I hope that this idea catches on, and I will continue to be an advocate for such program development!
Vestibular Rehab Guidelines
Individualized to a patient's needs and tolerance, is more effective than just a standard protocol
Time: At least 20 minutes total a day of gaze stability & 20 minutes of gait/balance
Speed Matters: the primary goal being to produce a retinal slip in adaptation. One should build frequency of head movement as quickly as tolerated with the image just on the edge of blurring.
Brightness: When performing gaze stability exercise good visual input is encouraged. Use a room with good light, open curtains, or turn more lights on.
Amplitude: small ranges of head movement are sufficient, and do not particularly have to be continuous
Time frame: Guidelines according to 2016 APTA Clinical Guidelines Neuro Section
Persons without significant medical comorbidities and with acute or subacute one-sided vestibular weakness: 1 x week supervised therapy sessions for 2 to 3 weeks
Persons with chronic one-sided vestibular weakness may need 1 x week sessions for 4 to 6 weeks
Persons with both inner ears affected may need once a week sessions for 8 to 12 weeks
In addition to supervised sessions, patients should be provided a daily home exercise program
These guidelines can obviously change or be modified, depending on a person’s needs, and can be discussed with a vestibular therapist.
If you have recently been diagnosed you can find support through the Acoustic Neuroma Association HERE. Read our blog HERE about the different medical approaches to treatment for Acoustic Neuroma.
