QandA

I have general questions in regards to establishing, marketing, and billing a balance clinic for private practice audiologists not associated with an ENT. Does Medicare require a referral for this test the same as audios, etc.. and if someone called in off the street with dizziness complaints (other than Medicare insurerers) can we do ENG testing without any kind of physician referral? If so, what is the climate of the physicians when they receive this report? Would they think audiologists are haphazardly doing ENGs or would they be receptive? My basic question is that I agree that most general physicians just prescribe Meclizine and send them on their way but if the patient came to see the physician on the initial visit with an audiologists report in hand do they view that as credible info? In other words, are we part of the loop as independent practitioners or would they view that as us overstepping our bounds?

Our clinic policy is to accept referrals for vestibular examination by physician referral only, regardless of insurance provider. We have Audiology and ENT under the same roof, part of the same corporation, so we could take all patients (including Medicare and Medicaid) directly. We choose not to do so for other reasons: 1. It is not unusual for us to see a patient that is dizzy secondary to non-otologic medical conditions or medication. 2. Occasionally, we will see a medical emergency walk in the door. 3. A patient with a vague dizziness complaint of short duration (a few days) probably doesn’t need a vestibular evaluation. If you see a patient with a potentially significant medical problem, you need to have somewhere to send them ASAP. The ENT guys in our group don’t want to deal with non-otologic problems. For all these reasons, we think it is best for the patient to be screened first by the primary care physician.

As far as the climate for how a PCP would view their patient going to Audiology first, I suspect it varies by locale and individual. Our approach is to present our clinic as there to help, not replace or substitute the PCP from the process. We focus all of our marketing for vestibular services on the PCP through newsletters, continuing ed. programs, mailing articles of interest, etc. The PCP that understands what you do will be your best referral source. Also, by only accepting PCP referrals, you are acknowledging the value and showing respect for the PCP role. Ultimately, I think you shoot yourself in the foot by accepting dizzy patients directly.

The obvious exception to the logic of my above argument is the patient with BPPV. Li, Li, Epley and Weinberg (2000, Oto-Head Neck Surg) report that in their study of patients with confirmed BPPV, nearly all were given Meclizine as the treatment, and that each patient saw (on average) 4 doctors about their dizziness before they got a correct diagnosis. Of course, this is horrifying when you know how prevalent and easy to treat BPPV really is.

I read an article in a Family Practice journal a few years ago (don’t remember exactly which journal) that recommended that PCP’s treat BPPV with meclizine and observe for 30 days. If the symptoms persist, then send the patient to a specialist for repositioning. That started me thinking about “What would the patient want if you presented the facts (as we know them)” 1. this is a benign inner ear condition, 2. It will likely improve on it’s own with no treatment. 3. the average duration of untreated BPPV is over one month (some studies say 2-3 months), 4. a trained specialist can probably resolve it immediately.

We decided to poll our patients. We went back to the previous 50 consecutive CRP patients, and asked them, “Knowing what you know now, the cause of your dizziness, the testing, the treatment, the cost, the time involved, would you return immediately for treatment or wait it out if your symptoms returned? Only one patient said they would wait it out. The other 49 said they “would definitely return immediately.” Clearly, patients with BPPV would prefer immediate referral as opposed to the AAFP recommendation. You can bet I share this information with PCP’s.

I receive frequent referrals from a local Otolaryngologist for ENG for patients with dizziness or vertigo who also have perforated TMs. I do use open loop air irrigations so I’m not questioning the safety of the testing. I did read the section on the “cooling reversal” seen in the warm air irrigations and had heard this before. I believe I may have observed this in one patient. I am curious if you recommend not performing the

A more minor question is that with VOG, I often have difficulty getting the tracking of the pupil to actually track the pupil with patients with mascara (as you mention) but more so with very dark skin. Mascara removal instruction has been added to patient instructions. However, are there any recommendations (other than equip. adjustment and packing the goggle area with white gauze) that you can recommend? I tried the white gauze trick

I think the simple answer is that patients with TM perfs or tubes are not great candidates for caloric testing. You can still determine if the labyrinth in question is responsive to caloric stimulation, but it would be difficult to use the same criteria for abnormal asymmetry that you would use for intact TM’s. An open TM just adds one more variable to a test that is fraught with potential sources for error. I would still do air calorics with a TM perf., but I would probably need to see a very significant difference in caloric response between ears before I felt comfortable that, in fact, there was a labyrinthine hypofunction. The moral is to not allow your evaluation to be dependent on any single test. See more on this in my response to the question posed by C. Bering about sensitivity of ENG.

There are some (not many) patients that are not good candidates for VNG for a number of reasons, several of which you mention. We have also found that some claustrophobic patients can’t tolerate the goggles and darkness. It is a good idea to have EOG recording as an option.

The only suggestion I can offer is to tinker with your tracking threshold control. We keep make up removal wipes in the exam room. I have talked with one manufacturer about making lighter colored goggles, but we still use the white gauze trick frequently. It works pretty well.

I had the opportunity to do probably hundreds of ENG’s both by strip chart, computer and with the infared goggles. I found that so many ENG’s were either cut and dry vestibular or somewhere in the shady region of Central. Ultimately, if the ENG provides signs of central deficits or lesions, what does the physician order next in terms of testing to further get to the bottom of the diagnosis or site of lesion? I used to send so many ENG results back to the Neurologist not knowing what he did with

I think most physicians would attempt to corroborate your “central” findings by doing other exams of cerebellar function, referring to Neurology, or ordering cranial MRI/MRA. We have a long standing clinic policy where we call each patient about 30 days after we see them. If we treated them either with respositioning or home based vest rehab exercises, we want to make sure they are doing well. If we referred them on for additional evaluation elsewhere, we want to know the outcome of that evaluation. This type of feedback helps us in refining our recommendations, and makes the patient feel cared about. It is a never-ending learning process for us.

vestibular hypofunction (ice water calorices were below 2.0 degrees/sec). Saccades and pendular tracking were essentially normal although she fatigued and small corrections were evidenced toward the end of the task. She reported taking Quinine 2 years ago for leg cramps which caused a severe tinnitus. She has constant disequilibrium and a brief “catch-up” dizziness when turning her head. Questions: Could the Quinine be the single causative factor even after two years? Should I be looking for more? What would be a possible treatment be for her (medication, rehab)? She has seen an ENT but I do not know what was reccomended yet. Thank you C

The information I have on effects of Quinine is not very definitive, so bear that in mind as I attempt this answer. Quinine has ototoxic effects similar to Aspirin, most notably, transient SNHL. It would be hard to blame a permanent bilateral vestibular hypofunction on brief use of Quinine. But, who knows for sure? Not me.

Lack of caloric responsiveness (even with ice water) does not mean that the patient has no vestibular response. This type of patient needs to undergo rotary chair and/or Active Head Rotation to examine the higher frequency VOR. The type of therapy recommended and the prognosis for improvement would be radically different depending on what you find in the higher frequencies.

The “catch up” dizziness that you mention would lead me to suspect that there is dysfunction in the higher frequencies as well. Read page 29 and see figure 2-8 in my book for an explanation. You could try Head Thrust testing (described on page 54) to verify the “catch-up saccade.”

Observed 50 yo female px past Friday that had significant congenital nystagmust. She also had strabismus (?-right eye perm. to the right). The nystag. ws significantly supressed with eyes closed.She even asked us if “we ever saw someone with this bad of congenital nystag”. Another Au.D. candidate was also observing.

I think it would be impossible to perform a meaningful exam on a patient with significant congenital nystagmus. The direction and intensity of the nystagmus changes depending on the patients gaze angle, which tends to vary throughout the caloric test period. Depending on complaint, posturography is doable and might be helpful.

I like to know practical stuff. In my geographical area, most places only have ENG testing. I would like to know why so many places opt not to have other forms of testing? What makes ENG more likely to be purchased by physicians? Is it that much more sensitive to vestibular problems and I guess then when would you recommended another form of testing be done, such as rotary chair, platform, etc?

This is really a great question, and I need to be careful not to get on my soapbox here. I did an article for the Vestibular Disorders Assoc. last year titled “Common Misconceptions regarding ENG”, a prelim draft of which is attached (attachment 2) at the end of these answers. The final version is in the VEDA Winter 2004/2005 newsletter. I think there are good and bad reasons that ENG is so dominant. The good:1. standard ENG protocol requires Dix-Hallpikes, which may identify the most common and most treatable vest. disorder, BPPV. 2. Provides recording and observation of gaze or spontaneous nystagmus with fixation removed for acutely dizzy patients. 3. Oculo-motors allow screening for dysmetria.4. Calorics allow identification of side of lesion (which is helpful if surgery is a consideration).

The bad reasons: 1. It’s been around for a long time. 2. The equip is relatively inexpensive and the reimbursement relatively high compared to other tests (Rotary Chair and Posturography). 3. The information confirming the superiority of Rotary Chair sensitivity over ENG has just been coming out over the past ten years. Many specialists (both Audiology and ENT) rely on what they learned in school so many years ago. 4. You absolutely, positively, undeniably can not rule out vestibular dysfunction based on a normal ENG.

Personally, I would recommend rotary chair on all patients, except those with BPPV that are asymptomatic after repositioning. If you find a caloric asymmetry, rotary chair will help you learn the level of compensation and as noted, higher freq function. If you don’t find a caloric asymmetry, rotary chair is more sensitive and may find a problem missed by ENG.

Electronystagmography, more commonly know as ENG, has been the mainstay of vestibular testing since Fitzgerald and Hallpike introduced the binaural bithermal caloric test in 1942. ENG actually refers to a battery of tests that examine different aspects of the vestibular system. This battery consists of (1) oculomotor tests, including evaluation for gaze and spontaneous nystagmus, (2) positional and positioning tests, and (3) caloric tests. There is some confusion regarding what information is actually obtained through an ENG examination as some clinics advertise “complete dizziness testing” or describe themselves as a “Balance Clinic” when their evaluation is limited to the ENG battery only.

The oculomotor tests involve evaluating the efficiency of voluntary eye movements that are modulated by the cerebellum, and are primarily used as screening tests for possible central nervous system (CNS) disorders. This portion of the test is usually performed prior to any tests of labyrinthine function, as oculomotor abnormalities can affect the validity of subsequent vestibular tests. For this same reason, examination for nystagmus (rhythmic involuntary eye movements) is completed at the beginning of the ENG exam.

Positioning and positional tests are performed to determine if the vestibular system responds normally and symmetrically to changes in head position. The most common vestibular pathology is Benign Paroxysmal Positional Vertigo (BPPV), and this condition can often be diagnosed by the positioning test.

The caloric test evaluates one vestibular apparatus (labyrinth and vestibular nerve) at a time. This is most commonly done by irrigating the tests ear’s ear canal with a stream of water, although other irrigation techniques may be used. The water is 7 degrees above and below body temperature, resulting in a temperature and density change in the inner ear fluid (endolymph). This causes a sensation of motion in the test ear, but because that motion is not detected in the non-test ear, a sudden asymmetry exists. This results in subjective vertigo and recordable nystagmus in most cases. The goal of the caloric test is to determine presence and symmetry of vestibular responsiveness (nystagmus) to this stimulation.

Clearly, the ENG battery is a critical element of the examination of vestibular function, and many vestibular abnormalities can be diagnosed within the constraints of this standard test battery. Unfortunately, when a diagnosis is made based only on the information obtained from the ENG battery, many treatable patients will be incorrectly told that they have normal vestibular function and that their dizziness is not the result of an inner ear problem. Recent published and unpublished data tell us that, in hindsight, up to half of those people may have incorrectly been given a clean bill of vestibular health. Given the fact that only a small percentage of patients complaining of dizziness are referred for vestibular evaluation, the importance of accurate and sensitive evaluation at the specialist level can not be overstated. Failure to diagnose a vestibular pathology can lead to increased health care costs as the patient, convinced that the inner ear has been ruled out, continues to seek diagnosis from other specialists. This is likely to lead to frustration and even depression, as untreated inner ear problems have been shown to have a significant impact on quality of life. This article will review some of the possible “misses” that can occur when more comprehensive evaluation is not made available to those with a normal ENG exam.

BPPV is by far the most common cause of episodic vertigo, and can be successfully treated in one or two office visits approximately 90% of the time. Unfortunately, our in-office data indicates that almost 40% of patients complaining of positional vertigo are not detected through positional testing at the time of the initial exam. In 2001, we asked a series of these patients to return a few days later for repeat positional testing, this time being careful to avoid any provoking movements for several hours prior to the repeat examination. On repeat testing, 40% (10 of 25) had a positive positioning test and a clear diagnosis of BPPV was made. Since that time, assuming the rest of the exam is negative, we start these patients of a home program of exercises known to speed up resolution of BPPV. Using this protocol, we have found that over 90% of patients have resolution of symptoms within 2 weeks, as opposed to the typical duration of symptoms lasting 9 to 12 weeks in untreated BPPV.

There is very little literature addressing the issue of BPPV which is inactive at the time of exam. For a more in-depth review see Norre (1994) Diagnostic Problems with Patients with Benign Paroxysmal Positional Vertigo, Laryngoscope, and/or Desmond (2002) Reduce False Negatives in BPPV Diagnosis, Advance for Audiologists. BPPV is such an easily treated, common condition that re-examination, or a trial of home treatment, should be considered when the complaints are suggestive of BPPV, but the exam is negative.

The Vestibular-Ocular Reflex (VOR) can be defined as reflexive eye movement in response to head movement. The role of the VOR is to allow for stable gaze (clear focused vision) while the head is moving. It is estimated that the frequency range of head movements encountered in real life is from .05 to 5 Hz, and the VOR normally responds efficiently up to frequencies approaching 8 Hz (Gresty, Hess & Leech, 1977, Sawyer et al., 1994). A 1Hz head movement would be a speed that would accomplish one full 360 degree head turn in one second, a .05Hz movement in 2 seconds, and so on.

Caloric testing has been estimated to stimulate the labyrinth comparably to a head movement in the .003 to .005Hz range. This would be analogous to head movement that would complete one 360 degree rotation of the head in 200 seconds. If you actually give this a try, you will see that this does not simulate real life head movements.

The higher speeds can be evaluated through rotational testing. Two techniques of rotation testing are commercially available. Rotational Chair (RC) is a passive test as the patient sits in a motor controlled chair that moves the patient at speeds typically from .01 to .64Hz. Active Head Rotation (AHR) involves having the patient voluntarily move their head back and forth at speeds of 1Hz up to as fast as the patient can move his/her head. RC is considered the “Gold Standard”, has good test-retest reliability and has been the subject of much research. AHR is used in more clinics in the United States, is less expensive to purchase the equipment (most likely explaining its wider usage), and simulates the condition (rapid head movement) most likely to elicit a complaint from a patient with vestibular dysfunction. Some vestibular specialists consider AHR experimental and are critical of its test-retest reliability (Guyott & Psillas, 1997). Regardless of test technique, rotational tests consistently demonstrate better sensitivity than ENG for detecting chronic vestibular pathology.

Shepard and Telian (1996) report on a group of 2266 patients undergoing vestibular evaluation at the University of Michigan. Sixteen percent of those patients had normal ENG examinations. They report”Among those with normal ENG results, RC indicated abnormalities suggesting peripheral system pathology in 80% of cases, 35% by phase abnormalities and 45% by asymmetry findings.” Jacobson (2002) performed comprehensive vestibular evaluation on a series of patients complaining of postural and/or gait instability. They found abnormalities on the caloric exam in only 25% of patients, while RC abnormalities were identified in 56%.

More recently, Arriaga, Chen and Cenci presented data (unpublished at printing) exploring the sensitivity and specificity of ENG versus RC testing on a series of 1000 patients. Their results are strikingly similar to Jacobson’s, in that 29% had abnormal ENG and 56% had abnormal RC tests. Only 10% of patients with normal RC had abnormal caloric studies, but almost 40% of patients with abnormalities on RC had normal caloric exams. They calculate that RC has a sensitivity of 71% for detecting vestibular pathology, as opposed to a calculated 31% for ENG testing. Because ENG had a substantially higher specificity than RC, they recommend using RC as a primary vestibular test and ENG as a confirmatory test.

Active head rotation testing has been shown to be significantly more sensitive than ENG in detecting abnormalities in patients with reports of balance disorders. Saddat, O’Leary, Pulec, and Kitano (1995) performed both caloric testing and AHR on 39 patients complaining of balance disorders. Of this group, 24 had abnormal caloric studies, but 37 had abnormal AHR tests. In the same study, they found that four of ten patients with confirmed acoustic neuroma had normal caloric studies, but all ten had abnormal AHR tests.

In contrast, bilaterally absent caloric responses might be misinterpreted as absence of vestibular function if higher frequency rotational tests are not performed. Goebel and Rowden (1992) report that two thirds of a group of 34 patients exhibiting bilaterally reduced caloric responses had normal gain of the VOR at .5 Hz. This type of information is critical to designing a customized vestibular rehabilitation program, as therapy for patients with total loss of vestibular function differs from those with residual vestibular function. Caloric testing only stimulates the horizontal semi-circular canal, while AHR records the response to horizontal and vertical head movement, allowing evaluation of the VOR in more than one plane.

Vestibular rehabilitation (VR) has gained popularity in the past decade, and has been shown to be an effective treatment for uncompensated vestibular dysfunction. Unfortunately, the ENG battery provides no information that can be used to determine candidacy for, or benefit from, VR. As noted above, the oculo-motor portion of the ENG is primarily at test of cerebellar function. Patients with dizziness of CNS origin might benefit from VR, but the prognosis is unpredictable. Patients with spontaneous nystagmus of labyrinthine origin are not necessarily candidates for VR as exercise has not been shown to increase recovery from tonic vestibular asymmetry (although many of these patients will develop a reduction in VOR gain and may be candidates for VR, this is not detected on ENG testing). The most commonly detected abnormality on positioning tests (BPPV) is treated with Canalith Repositioning, and not ongoing VR. A caloric asymmetry can exist in a well compensated vestibular injury. A documented unilateral weakness does not necessarily indicate that a patient will benefit from VR, and a caloric weakness will not diminish as a result of VR.

The ENG battery is a necessary part of the work up for diagnosing vestibular disorders, but the information obtained must be put in context with the patients complaints. A normal ENG exam does not mean that no vestibular abnormalities exist. Unless the ENG yields an answer to the question, “Why am I dizzy?” additional studies are indicated. To say that there is no vestibular problem based on normal ENG findings, would be equivalent to saying your keys are not in your house because you didn’t find them on the kitchen counter. The moral of the story, “If you don’t find what you are looking for, look elsewhere.”

I also like to know what suggestions are given for testing patients who present with multiple disorders, such as a blind person with sudden balance issues, or a patient who is low-functioning? We mainly talk about adults and vestibular disorders, but wouldn’t children and teenagers have vestibular disorders that should be tested? I wonder if there are norms available for testing young individuals and if any difference in the values

As stated earlier, not all patients are candidates for all tests. You can test and treat BPPV effectively in blind patients, and you can do uncalibrated calorics. If the pt is so low functioning that they can’t calibrate, same thing applies. Most old unstable patients will have more than one issue affecting their balance, and some issues are out of the scope of practice of Audiology to evaluate. It is important to have a relationship with physical therapists that can assess the patient for things such as leg strength, sensation, range of motion, joint stability.

The majority of kids with vertigo have a variant of Migraine, and vest testing is usually normal. I have an opinion (logical, but I am not sure correct) about pediatric vestibular patients. Vestib therapy is all about stimulating compensation through plasticity of the CNS. Kids have two things going for them: 1. incredible plasticity 2. play that involves lots of stimulation. Basically, give a kid a ball, a hoola hoop and a wrestling mat, and you’ve got yourself one heck of a vestibular rehabilitation program.

Dr. Desmond- I am finding a range of what constitutes “significant” UW and DP between our required readings, and outside sources, I am finding different opinions on what terms air calorics are to be presented, from “the same as water” in one reference, to different values that all agree from most other sources, and finally the time an air caloric should be presented. One outside source gave an elspased time that is greater than what our office use.

The above questions are relevant because our two offices (that do ENG) uses air calorics. Seems like everyone has their own opinions and practices regarding ENG procedures, even within the same practice. This concerns me because such variations have to effect over all reliability. Your comments please. Thanks. C. B.

Dave Zapala had a good article about this in Audiology Today (Jan 05), so I will refer you to that. I think your “significant weakness number” can change based on other factors. If we see a patient with an asymmetry on rotary chair, we might consider a caloric difference of 15% significant.

1. I will answer the first part with a short blurb from a book chapter I am currently working on. Keep in mind that equipment is only as good as the person operating and interpreting the information. I say this because of the growing number of “balance clinic” packages being marketed that try to convince the clinicians that if they follow a flow sheet, they too can be a balance specialist. Unfortunately, it is not that easy, and you owe your patients better. To answer the question, ideally you would have all three components: ENG -to diagnose and treat BPPV, identify possible CNS disorders and significant caloric hypofunction, rotary chair to identify vestibular patients that will be missed by basic ENG and determine level of compensation, and posturography to identify patients with non-vestibular balance disorders and to see how vestibular patients have adjusted to their condition.

“An Audiologist interested in offering vestibular services needs to understand that, unlike hearing aid dispensing, they can not function effectively as a solo practitioner. The comprehensive evaluation and treatment of the dizzy and/or balance disordered patient requires a multi-disciplinary team approach, which minimally consists of a medical director, audiologist and physical therapist. Not all patients need the services of all these specialists, but some need the services of all three.

Offering vestibular services does not have to be a “none or all” proposition. Miller (2003) describes the various clinical and equipment options available, and suggests a “Hub and Spoke” arrangement where many patients can be effectively managed at smaller, less equipped clinics. Patients with more difficult to diagnose complaints, or with balance problems of a multi-factorial nature can easily be referred to a more comprehensive regional facility. Those practitioners in less equipped facilities should develop a relationship with a regional comprehensive clinic. A mutually beneficial relationship would involve the “Hub” clinic offering training and providing remote consultation to the “spoke” clinic, and the “spoke” clinic referring challenging patients to the “hub” clinic when more comprehensive evaluation is indicated.

There are two basic models for “spoke” clinics. The first is Audiology based where an Audiologist, focused primarily on diagnostic audiometry and hearing aid dispensing, wishes to add some vestibular services to their practice. Offering ENG, rudimentary posturography, canalith repositioning and home-based vestibular exercises can provide sufficient evaluation and effective treatment for many vestibular patients. Patients that are unresponsive to treatment, or do not have a firm diagnosis after ENG exam should be referred to a better equipped specialty clinic. Limiting the evaluation of the dizzy patient to audiometrics and ENG will result in many patients with treatable vestibular disorders incorrectly being told they have normal vestibular function (Desmond, 2005).

The second model is Physical Therapist based. Most Physical Therapists receive some training in treatment of gait and postural instability, but very few have the training or equipment needed to diagnose and treat more subtle vestibular disorders. In this model, the PT may refer more challenging patients to the ‘Hub” clinic for ENG, Rotational Chair or CDP, while the “Hub” clinic may depend on the PT based “spoke” clinic to provide neuro-muscular assessment and vestibular rehabilitation therapy in more remote geographical areas.

Traditionally, vestibular specialty clinics have been restricted to major teaching hospitals associated with a large university and/or medical school. This is largely because of the sizable obstacle of the cost of equipment encountered when considering adding vestibular evaluation capabilities to a clinic. The standard triad of vestibular evaluation equipment includes computerized electronystagmography (ENG), rotary chair testing, and computerized dynamic platform posturography. The cost of this equipment can approach, or even exceed, $200,000, which may prove cost prohibitive for many smaller private clinics. In the past several years, however, equipment manufacturers have been working to provide lower cost alternatives that will hopefully allow more Audiology offices to offer vestibular management, increasing access to appropriate care.

There are many equipment options to consider, and the following section describes the advantages and disadvantages of some of these options:” This section will appear in the upcoming Thieme Multi-volume series: Audiology: Diagnosis, Treatment, and Practice Management, Second Edition.

2. There are too many variables to make a reasonable estimate as to when a balance clinic might be profitable. It depends on patient volume, which depends on marketing and results. Reimbursement is inconsistent by insurance, location and over time. Keep in mind that a balance clinic brings in a lot of patients that otherwise would not visit an audiology clinic. Many of these need hearing aids, some get them. So you have to factor that into a profitability equation.

3. I discuss marketing in ch 8 of my book, but we find that marketing to physicians works best for us now that we are established. When we started the clinic, we marketed to the hospitals to convince them that this would be a good thing to be associated with, and they helped us with equipment financing, marketing to the medical staff , etc.

To learn about vestibular management, you need courses like the one you are taking now, lot’s of reading and spending time with a seasoned clinician. To stay current, I do a few things. I periodically get onto Pub Med and type in applicable keywords, read the abstracts, and order any articles of interest. I also look for articles in JAAA and Oto Head Neck Surg. I attend courses at AAA. and always seem to learn something new.

I agree that it is impractical to expect patients to stop meds prior to undergoing ENG. Here’s why: If you leave it up to the referring physician, they won’t do it. If you instruct the patient yourself, you can create a big problem for yourself as Audiologists can’t prescribe meds (therefore can’t tell a patient to stop a med prescribed elsewhere). Some meds can not be stopped on short notice. Patients, despite your best efforts, will misunderstand and stop a med that they shouldn’t.

You do need to consider the effects of meds on oculomotors (except if you see an asymmetry, meds would not cause that), but we see many patients, on all kinds of sedating meds with normal oculo-motors. Also, meds can cause bilaterally reduced caloric response (but not an asymmetry) and reduced gain and phase abnormalities on rotary testing. So, if you get an abnormality described above, you must make note in your report, and maybe recheck when the patient has reduced meds. Most often you will be able to complete your test despite any meds.

A 73 year old patient has had balance issues following a stroke or multiple mini-strokes,(in cerebellar area) in 2001 that did not affect communication in any way, and initially only caused some swaying when walking. His condition has since deteriorated. He was not prescribed any extensive therapy. No ENG, just MRI and CT scan. Also,he has been

Two of the four parts of the body responsible for balance appear to have known deficits. Somatosensory information is compromised by periph neuropathy, and cerebellar integration may be affected by CVA. It would be helpful to know the status of the visual and vestibular systems, as these may be all that’s keeping the old fellow upright.

I agree that if vest eval was normal, he would not be a candidate for vest rehab., but a PT would sure like to know the status of the vest system before beginning any type of balance therapy. I think you can’t know if vest rehab would help until you know the status of the vest system.

independent medical examiner who does a lot of medical/legal evaluations for insurance and workman’s compensation cases. He would like us to start performing some basic vestibular evaluations so that we can provide him with more information for his reports. Where should we start? What tests do you recommend? What equipment is necessary? I apologize for this being such a simplistic question, but we are starting from scratch and need some direction. Thank you!!

I would recommend arranging for a minimum of one week visit to a regional balance center. I wouldn’t do any tests until I understood how that test fit into the overall picture. Also, you are going to need some guidance and a place to refer more difficult patients. The regional balance center will most likely be happy to help out in exchange for referrals when indicated.

According to Dr David Zee, the guru of eye movements, the cause of congenital nystagmus is unknown. It might be interesting to find your friends “null point.” There is, I think always, an angle of gaze where the nystagmus stops. Also, have your friend read something for you. Many patients with congenital nystagmus will either hold the book off to the side a bit, or rotate their head so they are looking at the book out of the corner of their eye. They have found their null point, and visually things get clearer when they gaze in that direction. I have seen several patients with congenital nystagmus with no vestibular or visual symptoms whatever. They were being seen for hearing problems. In this part of the country, they are referred to as dancing eyes.