By Tony Friese, PT
Competency Certificate in Vestibular Rehabilitation
Vestibular rehabilitation therapy basically boils down to 4 things:
1)-Repositioning for BPPV. BPPV (Benign Paroxysmal Positional Vertigo) is a condition where the little stones (otoconia) have come loose inside the utricle and wander into one of the semicircular canals, usually the posterior canal. The particles can come loose for a number of reasons, but is usually degenerative in nature. Presence of the otoconia in the canals adds an abnormal degree of “weight” to the fluid of the canal meaning that movement in the plane of the canal creates an abnormal degree of stimulation of the sensory receptors in the canal which is felt as a “spell” of dizziness, lasting as long as the movement of the particles in the fluid persists (usually less than one minute). Symptoms are typically intermittent in nature and are not accompained by hearing related symptoms. Imbalance is common and nausea and vomiting occur with the condition more than occasionally. The gold standard clinical test for BPPV is the Dix-Hallpike test. With the Dix-Hallpike test, the patient is monitored not only for reproduction of their familiar dizziness, but also for nystagmus-reflexive eye movement generated by the VOR and specific for the canal being stimulated.
[youtube=http://www.youtube.com/watch?v=rtS2muvjFbM] Once a positive Dix-Hallpike test has identified BPPV, treatment is carried out with techniques called canalith repositioning. Canalith repositioning is a series of changes in head position designed to relocate displaced otoconia back into the utricle at which point they cease creating symptoms. The most common repositioning maneuver is called the Epley maneuver, named after it’s inventor, Dr John Epley.
[youtube=http://www.youtube.com/watch?v=eOuzUi5ckrk] BPPV is the most common cause of vertigo from a peripheral vestibular disorder and is estimated by some experts as comprising as much as 20% of all dizziness. BPPV is estimated to occur in 50% of the over 70 population so it’s better to assume it’s there with any dizzy or unbalanced patient until evaluated and proven otherwise. BPPV is highly responsive to treatment with maneuvers such as the Epley maneuver and have an estimated overall effectiveness of about 80% with a single treatment. Reoccurence is common happening in about 25% of sufferers within one year. Patients can often do home based versions of repositioning maneuvers for reoccurent BPPV. An excellent overview of BPPV eval/treatment is here. This site is updated a few times a year as new literature becomes available.
2)-Vestibular adaptation exercises. These are designed to help the balance system basically reprogram itself after a deficit (unilateral or bilateral impairment or loss) Adaptation exercises seek to fine tune the performance of two reflexes involving the vestibular system, the VOR (vestibuloocular reflex-for gaze stability which allows effective use of vision for balance) and the VSR (vestibulospinal reflex for postural stability).
Adaptation exercises involve challenging these reflexes at a level that causes an “error” in their performance. For example, for the VOR, focusing the eyes on a target and moving the head at a frequency that creates a very mild blurring and maintaining this for 1-2 minutes. With a healthy CNS, input from the vestibular system will be recalibrated by the cerebellum and vestibular nuclei to become better at maintaining stable vision with increased speed of head movement. These are the exercises the ENT was referring to as “inner ear strengthening”. An example of the most commonly used of these exercises can be seen here. A test to see if this type of exercise is indicated is the dynamic visual acuity test. This test involves having a pt read the lowest line possible on an eye chart, then comparing this with the lowest line possible when the head is passively moved by the therapist (horizontally) at 2Hz. If the vision with head movement is more than 2 lines worse than with the head still, there is likely an impairment in VOR function .
For the VSR this is where generalized standing balance exercises apply. Testing VSR function and what sensory systems a patient needs improvement with is often done with the modified Clinical Test of Sensory Interaction in Balance (aka CTSIB, see here) . For adaptation exercises, the “error signal” sought here is a mild to moderate sway while attempting to maintain balance. The exercises most likely to directly target use of vestibular input would be those on a compliant surface (foam) with vision reduced or eliminated (eyes closed, sunglasses, head moving). Of course many people have to start much more simply than this (solid ground>compliant, feet apart>together, eyes open>closed, head still > moving) As with VOR exercises, 1-2 minutes at a time is the typical suggestion. Home exercises for both VOR and VSR are encouraged typically 3-5x/day.
3)-Habituation exercises. These are for movement provoked dizziness not due to BPPV (although they can be used for BPPV as well, particularly if unresponsive to repositioning maneuvers). These involve identifying movements that provoke dizziness either through patient history or through a more standardized test called a Motion Sensitivity Quotient. Once provoking movements are identified, exercises are designed based on those movements with the intention of causing habituation (ie desensitization). Habituation occurs in response to repetition of provoking movements. For example, if rolling in bed caused dizziness, the exercise would involve rolling in bed at a speed that provoked mild to moderate symptoms, then remaining in the position until the provoked symptoms subsided, then returning to the start position and repeating. Typically up to 3 or 4 movements are used, doing 3-5 repetitions at a time. While recovering from provoked symptoms in any exercise, the person is encouraged to use visual and somatosensory information (feeling the supporting surface, focusing eyes on clear visual target) to speed the recovery.
4)-Substitution exercises. For people with a complete loss of vestibular information (primarily for bilateral impairments)exercises emphasizing use of somatosensation or stable vision are encouraged. Examples would include balance exercises on solid ground with the eyes closed to promote use of somatosensation, and balance or vision exericses where the person learns to use voluntary eye movements to fixate on stable visual targets prior to/instead of moving the head. And example of such an exercise can be seen here.
These general categories are but a brief overview of the types of things that are done with vestibular rehabilitation. While foreign to many therapists that didn’t learn about it in school, it can be a very rewarding area of practice if time is taken to study and learn something new. For me, it was a bit of an awkward beginning, but now has evolved into my main area of clinical concentration and provides me a nice contrast to the often frustrating arena of treating painful disorders (although vestibular rehab has more than its share of challenges as well!). There are many resources online where more information is available including references. I would especially like to acknowledge Jeff Walter, DPT, NCS and his website www.vestibularseminars.com from which I linked several of the videos above. Dr Walter also teaches 2-day introductory courses across the country each year. There are also many other high-quality introductory and advanced courses courses available through other seminar providers. I hope this has been a helpful overview of vestibular rehabilitation and want to thank Joe Brence for inviting me to write this post.
By Tony Friese, PT