Although most sufferers of BPPV describe a spinning sensation, other surprising descriptions occur with BPPV. It is important to review these because quite often a spinning description is denied by patients with BPPV. Patients with BPPV, while denying spinning, may report lightheadedness, faint feeling, seeing double, passing out, or, falling for no reason. It is unwise to rule out BPPV just because a patient denies spinning or reports a symptom that seems not to indicate BPPV. Often, patients who describe only feeling “lightheaded” in certain positions are cured of these feelings after an Epley maneuver. It is likely that patients find it hard to describe an experience like vertigo which they have never had before. Also, many older patients with BPPV feel their vertigo symptoms to a much lesser extent or even not at all.
Characteristics of Nystagmus in BPPV
The cause of the patient’s brief vertigo is a jerking reaction of the eyes (nystagmus) due to crystals’ movement in the semicircular canals which disturbs hair cells in the inner ear’s “ampulae” located at the end of each of the canals. Crystals do not have to actually bump into these areas, but the movement of the crystals can cause the inner ear fluid to push toward or away from the ampulae, stimulating the hair cells. When hair cells are thus artificially disturbed, the vestibular ocular reflex (VOR) is triggered to a greater extent than usual, causing the eyes to undulate rapidly for several seconds. Whereas the term nystagmus refers to any eye movements which have a rhythmic jerking pattern, the type of nystagmus seen in BPPV, has a fast-slow pattern, usually with a rotatory component.
Disturbance of crystals in the posterior canal usually cause nystagmus in a upward, rotatory direction, whereas nystagmus caused by crystals in the horizontal canal, if free floating (canalythiasis), is purely horizontal, short lived, with fast phase toward the ground (geotropic) when lying on the affected side. If crystals are stuck (cupulolithiasis) in the horizontal canal, nystagmus is less brisk, continuous for several minutes and away from the ground (ageotropic) when lying on either side.
We use the standard Epley maneuver for posterior canal BPPV, the log roll (Bar-B Que roll) away from the bad ear for horizontal canal canalythiasis, and various maneuvers for the more difficult to clear horizontal canal cupulolithiasis. For the latter case, the author has visited several noted clinics inquiring about their choice of maneuvers is for “stuck crystals”. From these visits as well as our experience, the following are our general procedures. When crystals are stuck in the horizontal canal (ageotrpoic bilateral nystagmus that does not go away after 2 minutes) we have the patient lie side to side, back and forth several times, staying about 5 seconds on each side. This often clears the crystals while at the office, which then results in the “free floating” canalythiasis form of horizontal canal BPPV (geotropic nystagmus, greater on one side that fatigues in about 1 minute or less). At that point, we perform the “log roll” away from the affected side, which usually clears the crystals immediately, shown by an absence of nystagmus or symptoms when retesting the side lying position. Details about the log roll, modified log roll (which we find just as good) and other maneuvers can be found easily on line. If the side to side method does not free crystals, we have the patient perform 30 seconds of lateral head shaking each morning as well as the Brandt-Darroff exercises at home. The patient is warned that once crystals clear (become unstuck), the patient will become extremely dizzy for a minute or two, which is a good sign that crystals are now free floating and easy to clear.
Crystals can also become stuck in the posterior canal or even the anterior canal. Details about maneuvers for these are beyond the scope of this article, but patients or clinicians are welcome to call us about this. We hope to present our experience with these less frequent maneuvers on-line in the future.
When patients who have normal Hallpikes (but still expected of BPPV) are treated with the Epley maneuver, the question of which side to perform is a difficult one. Patients are often wrong about identifying which side is the culprit. In our clinic, we perform both sides on separate visits one week apart.
Non-BPPV Positional Vertigo
Positional vertigo and/or nystagmus can also be caused by disorders other than BPPV including central nervous system disorders; however, nystagmus that is triggered by a head position, then fatigues after several seconds while still maintaining the position, usually indicates BPPV. The eye movements start usually from 0 to a few seconds after the head is put into the triggering position but can start later much later (45 seconds or more). For this reason it is important to maintain the Hallpike position for at least 45 seconds. Once the response begins, the eyes will usually stop jerking within 1 minute (while the head maintains the Hallpike position).
Patients having had stroke within the past 6 months or even longer should have permission from their primary physician before attempting the Epley maneuver. Other sensitive cases are those with neck disease or past back or neck surgery within the past several months, for which permission should also be obtained.
Modifications for Restricted Neck or Back Cases
A side lying version of the Hallpike consists of having the patient, while seated, turn the head to the opposite direction of the ear being tested, then lay sideways, which puts the head back into the same position as the backward lying Hallpike. Another modification of the Hallpike test is to use a pillow under the patient’s back, which allows the head to go back beyond the pillow into the Hallpike postion without hanging back over the edge of the bed. I find this technique very useful and usually as effective as having the patient’s head off the bed, which is very practical for hospital patients. Richard Gans has also published a modified Epley maneuver, the Gans Maneuver, for those with back problems or other physical characteristics that prevent a normal Epley maneuver.
Take Home Exercises
Prior to the Epley and similar maneuvers, there were take home exercises that were somewhat successful, such as the Brandt-Darroff exercise in which the patient goes from sitting to lying on either side repeatedly. This is still also used in some cases of “stuck crystals”. Some patients with neck or back disorders are difficult to treat with the maneuvers. Some will also refuse the Epley maneuver due to having had a bad experience, which may just mean they felt very dizzy unexpectedly. Other “bad” experiences can occur when patients either self-perform the maneuver without success or become extremely nauseated during a maneuver. For such reasons, a patient may refuse further maneuvers. At that point, the older take-home exercises may be acceptable to the patient, although usually less effective. Again, success with “do it yourself exercises” is considered much lower than with clinician performed maneuvers.
Common Pitfalls When Dealing With BPPV:
1. BPPV can be present even with a normal “Dix-Hallpike” test. See above. 2. Older patients often deny vertigo with BPPV, just describing general imbalance. 3. Some patients are so surprised by their first spell of BPPV, that they may report losing consciousness, losing coordination, seeing double, or even seeing spots. The patient usually has not really experienced these things, but these expressions may be used due to a lack of an adequate way of describing the BPPV experience. Once the experience is reproduced in the office by putting the patient into the Dix-Hallpike position, the patient may exclaim, “that’s exactly the way I felt”. If a patient does feel the unusual symptoms mentioned above, and testing is normal, the patient may have a non-BPPV cause of vertigo such as cardiogenic or the central nervous system. Again, it should be remembered that patients with true BPPV sometimes have negative Hallpikes. 4. Central nervous system disorders can mimic BPPV eye movements, but usually with CNS disorder, nystagmus does not fatigue while in the Hallpike position. 5. Many cases of simple BPPV can appear to be central nervous system disorders on VNG due to oculomotor abnormalities on the test. Oculomotor abnormalities do suggest a central nervous system problem, but BPPV is so common, even when Hallpikes are normal, CNS should not immediately be assumed to be the cause of the vertigo. CNS problems may coexist with BPPV and be a red herring when it comes to deciding what is causing the vertigo, which is more often BPPV. A well-known pioneer of vestibular testing, Charles Stockwell stated in a lecture I attended that “80% of the patients you will see in the vestibular clinic will have BPPV”. I have found this to be the case. 6. Many cases of presumed “postural hypotension” (orthostatic hypotension, in which dizziness is caused by a sudden drop in blood pressure going from lying to sitting or standing) are really caused by BPPV. Again, postural hypotension may co-exist with BPPV, and in the absence of a positive Hallpike, the blame may be falsely given to the postural hypotension. Momentary vertigo caused by rolling to the side in bed without sitting up is rarely caused by anything other than BPPV. Also, just sitting up or lying down can sometimes trigger a BPPV spell. 7. Too often in older patients, dizziness caused by undiscovered BPPV is attributed to medication, high blood pressure or cardiogenic issues.
Common Questions Regarding BPPV
Do Crystals Come Back? Sometimes this occurs, but fortunately, the maneuver can be performed again if this happens. In about 20% of cases, crystals come back again. It is possible that these are “new” crystals rather than the old ones coming back. In some inner ear disorders such as Meniere’s Disease, crystals can be displaced as a by-product of the Meniere’s (about 50% of cases of Meniere’s develop crystals), therefore, cases where crystals occur more than twice should receive more thorough vestibular testing in order to search for an “underlying” inner ear cause.
Are the Maneuvers painful or Dangerous? What are the Disadvantages? There should be no pain involved. After the Epley maneuver, some patients will feel an immediate falling sensation when sitting up for the first time as crystals return to the utricle area. This reaction (Tumarkin crisis) can occur anytime up to a few hours after the maneuver and so precautions must be observed. Some patients may feel more dizziness for the rest of the day than they usually do, and in a very small number of patients, dizziness of nausea will remain for several hours, sometimes requiring symptom medication for a short time. For this reason, it is usually best not to undergo the maneuver on a day when there is an important event afterwards. Also, because of the back and down head positions which are maintained for about 1 minute, there are certain patients for whom this might be painful or risky. See above for more on this subject.
How do the Crystals Get Out of Place to begin With? Inner ear “crystals” most often simply fall from the utricle into the semi-circular canals over time. This is because the utricle sits above the semi-circular canals when a patient is lying down, which explains why many patients first notice the disorder when getting out of bed. In some individuals, inner ear crystals can accompany more serious inner ear or neurological disorders, therefore, recurring cases need to be given a more thorough work up.
There are things we do not yet know about the genesis of BPPV. Research is underway at a dozen or so world famous institutions regarding the cause of crystals and their leaving their place in the utricle. From the research so far, it appears that there are several different ways this can occur. Possible pathologic mechanisms include allergic irritation, viral irritation, Meniere’s related irritation, hormonal factors, trauma and several others. I have one patient who repeatedly sustains a bout of BPPV, which sometimes escalates to a full Meniere’s episode after being intoxicated by alcohol. This often includes also, a new, positive Hallpike response.
Relation of BPPV to Meniere’s Syndrome
The just mentioned case brings up one final topic worth mentioning, that is the possible relationship between Meniere’s syndrome and BPPV. Although it is recently being again questioned whether or not the actual cause of Meniere’s syndrome is fluid build-up in the endolymphatic duct, it is still recognized that fluid build-up occurs in many cases of Meniere’s. Researchers have recently discovered crystals associated with the area of the endolymphatic duct, raising the question, ‘can crystals clog the duct leading to fluid build-up?’ This raises a “chicken or the egg” question, does Meniere’s cause crystals to break free, or instead, do loose crystals lead to Meniere’s? Or, do both things occur? Studies are currently underway regarding the genesis and chemical properties of crystal formation and their degradation, causing us to feel that the future looks bright for greater understanding of BPPV. And since kidney stones also are usually composed similarly to ear crystals (calcium carbonate), the answer to solving kidney stones may be the answer to solving BPPV. Relationships regarding calcium metabolism in the digestive system appear to offer hope for the future resolution of the problem.