Benign paroxysmal positional vertigo (BPPV) is a common clinical disorder characterized
by brief recurrent spells of vertigo often brought about by certain head position
changes as may occur with looking up, turning over in bed, or straightening up after
bending over. The Dix–Hallpike maneuver induces vertigo and a burst of nystagmus with
characteristic directional features that permit localization to the affected side
and the affected semicircular canal in most cases.
Benign paroxysmal positional vertigo is an important cause of vertigo with a prevalence
of 11 to 64 per 100,000 and a lifetime prevalence in general practice of 2.4%.[1]
[2]
[3] In one study, 9% of elderly patients that underwent a comprehensive evaluation for
nonbalance-related problems were found to have previously unrecognized BPPV.[4] Delays in the proper diagnosis and treatment of this condition are still common,[5] and can lead to unnecessary costs and limitations of function.[3]
[6]
The importance of recognizing this condition is underscored by the ease and effectiveness
of treatment techniques that eliminate symptoms and the need for expensive testing.[7] The pathophysiologic mechanisms that underlie this condition will be reviewed, as
well as the clinical features of BPPV that allow its diagnosis, and the effective
methods for treating BPPV.
PATHOPHYSIOLOGY OF BENIGN PAROXYSMAL POSITIONAL VERTIGO
PATHOPHYSIOLOGY OF BENIGN PAROXYSMAL POSITIONAL VERTIGO
Anatomic Background
The vestibular part of the membranous labyrinth consists of three semicircular canals:
the anterior, posterior, and horizontal canals (Fig. [1]). These canals detect turning movements of the head. The labyrinth also consists
of two otolith structures, the utricle and saccule that detect linear acceleration,
including detection of gravity. The cupula is the motion sensor for the semicircular
canal, and it is activated by deflection caused by endolymph flow.
Figure 1 Membranous labyrinth. (Reprinted with permission from Barrow Neurological Institute.)
The macula of the utricle is the presumed source of the calcium particles that cause
BPPV. It consists of calcium carbonate crystals (otoconia) embedded in a gelatinous
matrix, into which the stereocilia of hair cells project (Fig. [2]). The calcium carbonate crystals are more than twice as dense as endolymph, so move
in response to gravity and other accelerative movements. The otoconial membrane consists
of a top heavy mass of calcium carbonate crystals overlying an elastic intermediary
that makes the macular receptor very sensitive to linear acceleration.[8]
[9]
Figure 2 Otolithic membrane of the macula showing the organization of calcium carbonate otoliths.
(Reprinted with permission from Barrow Neurological Institute.)
Mechanistic Basis of BPPV
Benign paroxysmal positional vertigo is caused when otoliths composed of calcium carbonate
that originate from the utricular macula dislodge and move within the lumen of one
of the semicircular canals. When the calcium carbonate crystals move within the semicircular
canal (canalithiasis) they cause endolymph movement that stimulates the ampulla of
the affected canal, thereby causing vertigo. The direction of the nystagmus is determined
by ampullary nerve excitation in the affected canal by direct connections to the extraocular
muscles. Each canal affected by canalithiasis has its own characteristic nystagmus
(Table [1]). Canalithiasis refers to the freely moving calcium particles within the semicircular
canal. Cupulolithiasis refers to the less common circumstance of calcium particles
adherent to the cupula itself. A concept of “canal jam” has also been proposed to
indicate calcium particles that can sometimes move, but sometimes become stuck within
the canal.[10]
Table 1 Nystagmus Features by Canal Affected in Benign Paroxysmal Positional Vertigo
| Canal Affected |
Direction of Paroxysmal Positional Nystagmus (Fast Phase) |
| Posterior canal |
Upbeating + torsional top pole beating toward downward ear |
| Horizontal canal |
Horizontal geotropic direction changing (right beating in head right position, left
beating in head left position) |
|
or |
|
Horizontal apogeotropic direction changing (left beating in head right position, right
beating in head left position) |
| Anterior canal |
Downbeating possibly with a slight torsional component |
The reason for this shedding of calcium crystals from the macula is not well understood.
The calcium debris may break off following trauma or viral infections, but in many
instances it seems to occur without identifiable illness or trauma. It may have to
do with age-related changes in the protein and gelatinous matrix of the otolithic
membrane. Patients with BPPV have recently been found to have more osteopenia and
osteoporosis than matched controls, and those with recurrent BPPV tended to have the
lowest bone density scores.[11] This observation suggests that the spontaneous release of otoconia may parallel
bone demineralization in general. It remains to be determined if treatment of osteopenia
or osteoporosis impacts on the likelihood of recurrent BPPV.
Canal Variants
Benign paroxysmal positional vertigo may affect the posterior, horizontal, or anterior
semicircular canal, and in some cases it may even involve more than one canal at a
time. Due to its gravity-dependent position, the most commonly affected semicircular
canal is the posterior canal. This accounts for ~85 to 90% of cases of BPPV; therefore,
when not otherwise qualified, BPPV generally refers to the posterior canal form of
the disorder. The horizontal semicircular canal is positioned within the membranous
labyrinth such that it may also be affected by the same mechanism, and accounts for
~10% of cases of BPPV.[7]
[12] The anterior canal and polycanalicular forms are the least common.[13]
DIAGNOSIS
DIAGNOSIS
The diagnosis of BPPV can be made based upon the history and examination. Patients
usually report episodes of spinning evoked by certain movements, such as lying back
or getting out of bed, turning in bed, looking up or straightening after bending over.
The episodes of vertigo last 10 to 30 seconds and are not accompanied by any additional
symptoms aside from nausea in some patients. Some patients that are susceptible to
motion sickness may feel queasy and lightheaded for hours after the attack of vertigo,
but most patients feel well between episodes of vertigo. If the patient reports spontaneous
episodes of vertigo, or vertigo lasting more than 1 or 2 minutes, or if episodes never
occur in bed or with head position changes, then one should question the diagnosis
of BPPV.
Posterior Canal Type
The diagnosis of BPPV of the posterior canal is confirmed by observing paroxysmal
positional nystagmus with the Dix–Hallpike maneuver. The Dix–Hallpike maneuver is
performed by rapidly moving the head from an upright to head hanging position with
one ear 45 degrees to the side. In Fig. [3], movement from sitting to head hanging comprises the Dix–Hallpike maneuver to each
side. The Dix-Hallpike maneuver results in torsional upbeating nystagmus corresponding
in duration to the patient's subjective vertigo, and occurring only after Dix–Hallpike
positioning on the affected side (Table [1]). A presumptive diagnosis can be made by history alone, but paroxysmal positional
nystagmus confirms the diagnosis.
Figure 3 (A) Dix–Hallpike positioning maneuver to the right. (B) Dix–Hallpike maneuver to
the left. Observe for a latency of 2 to 6 seconds after positioning before the onset
of nystagmus. Observe for nystagmus that is upbeating and torsional with duration
of 10 to 30 seconds. The side with the downward ear is the affected side in benign
paroxysmal positional vertigo of the posterior canal. (Reprinted with permission from
Barrow Neurological Institute.)
Lateral Canal Type
Horizontal canal BPPV may sometimes be evoked by the Dix–Hallpike maneuver. However,
the most reliable way to diagnose horizontal BPPV is by a supine head turn maneuver
(Pagnini–McClure maneuver) (Fig. [4]). The examiner looks for horizontal nystagmus upon turning the patient's head to
one side, then turns the head back to the supine face-up position. Then the head is
turned to the other side. The side with the most prominent horizontal nystagmus is
generally assumed to be the affected side.[14]
[15]
Figure 4 Supine head turn maneuver to determine the presence and affected side of horizontal
canal benign paroxysmal positional vertigo. (Reprinted with permission from Barrow
Neurological Institute.)
The nystagmus of horizontal canal BPPV, unlike that of posterior canal BPPV, is distinctly
horizontal and changes direction with changes in head position. The paroxysmal direction
changing nystagmus may be either geotropic or apogeotropic (Table [1]).[14] Geotropic direction-changing positional nystagmus is right beating upon turning
the head to the right and then left beating when turning the head back to the left
side. Conversely, the apogeotropic form indicates the nystagmus is right beating with
turning to the left and left beating with turning to the right. The latency is often
brief, and the duration may be 15 to 60 seconds. This nystagmus appears less apt to
fatigue with repeat positioning than in cases of posterior canal BPPV; consequently,
patients are more likely to become ill with attempts to fatigue this form of BPPV.
There is speculation that apogeotropic direction-changing nystagmus suggests cupulolithiasis,
and geotropic nystagmus suggests canalithiasis as the mechanism.[13]
[16]
Anterior Canal and Polycanalicular Types
The anterior canal form of BPPV is associated with paroxysmal downbeating nystagmus,
sometimes with a minor torsional component following Dix–Hallpike positioning.[17]
[18]
[19] This form may be encountered briefly in the course of treating other forms of BPPV,
but occasionally presents de novo. Chronic or persistent anterior canal BPPV is rare.
Of all the types of BPPV, anterior canal BPPV seems to resolve spontaneously most
often. Its diagnosis should be considered with caution because downbeating positional
nystagmus related to brainstem or cerebellar lesions can produce a similar pattern.
In a review of 50 patients with downbeat positional nystagmus, Bertholon et al found
that three-fourths had central nervous system (CNS) disease, while at least some of
the remaining one-fourth of cases were thought to have a form of anterior canal BPPV.[20]
Polycanalicular BPPV is uncommon, but indicates that two or more canals are simultaneously
affected at the same time.[19]
[21] The most common circumstance is posterior canal BPPV combined with horizontal canal
BPPV. The nystagmus will nevertheless continue to follow the patterns of single canal
BPPV, although treatment may have to be undertaken in stages in some cases.
Canal Switch
Occasionally, freely mobile otoconia moving within the lumen of one semicircular canal
can be moved during the course of treatment; not back to the vestibule as intended,
but to one of the adjacent canals, as the canals all directly communicate with one
another. This “canal switch” changes the appearance of nystagmus from that of the
original affected canal to that of the newly affected canal.[10]
[22]
[23] The most common canal switch is from the posterior to the horizontal and posterior
to anterior canals.
Distinguishing from Central Causes
Typical BPPV is usually easily recognized as such and responds to treatment. The forms
of positional vertigo that most commonly lead to confusion are those with downbeating
nystagmus (see discussion on anterior canal BPPV above), or those in which the nystagmus
is not truly evoked by the positional maneuver, but are nevertheless evident while
the patient is in the head hanging position. Table [2] outlines some of the features that may help separate central from peripheral positional
vertigo. As a general rule, if the nystagmus is anything other than the typical, or
if it fails to respond readily to positioning treatments, a central cause should be
considered.
Table 2 Features Distinguishing Central from Peripheral Causes of Positional Vertigo
|
Central |
Peripheral |
| Severe nausea |
+ |
+++ |
| Worse with nonspecific head movement |
++ |
- |
| Paroxysmal upbeating and torsional nystagmus with Dix–Hallpike maneuver |
- |
+++ |
| Paroxysmal horizontal direction changing nystagmus (geotropic or apogeotropic) evoked
by supine head turning |
+ |
++ |
| Persistent downbeating nystagmus in any position |
+++ |
- |
| Nystagmus diminishes (fatigues) with repeat positioning |
- |
+++ |
| Nystagmus and vertigo resolve following positional treatment maneuver |
- |
+++ |
Dizziness without Nystagmus during Dix–Hallpike Positioning
Sometimes patients with a history compatible with BPPV report dizziness upon Dix–Hallpike
positioning, but no nystagmus is seen. If this occurs on one side but not the other,
it is suggestive of BPPV. Repeat positioning is worth trying as sometimes the nystagmus
emerges on a second or third attempt, possibly based on the concept of “canal jam.”
An alternative possibility, especially when the dizziness without nystagmus occurs
with Dix–Hallpike positioning on both sides, is another type of vestibular disturbance
that is aggravated by the process of quick motion. In the absence of any other neurologic
symptoms, some home positioning exercises followed by reevaluation or a limited course
of vestibular physiotherapy can be considered.
TREATMENT
TREATMENT
Treatment of Posterior Canal BPPV
Treatment of BPPV is shown in Fig. [5] that depicts the canalith repositioning maneuver, sometimes referred to as the “Epley
maneuver” or canalith repositioning maneuver. Fig. [6] illustrates the Semont maneuver, which is an effective alternative treatment method.
Both maneuvers and variations of them are designed to clear calcium debris from the
posterior semicircular canal by moving it back into the vestibule by the effects of
gravity because the calcium carbonate crystals sink in the endolymph. Once the calcium
carbonate crystals are back in the vestibule, they are absorbed within a period of
days in most patients. If properly done, the canalith repositioning maneuver eliminates
BPPV immediately in greater than 85% of patients.[7]
[24] Similar success has been reported with the Semont maneuver (Fig. [6]). Patients that do not respond to canalith repositioning have calcium particles
that are immobile or that are attached to the cupula. Benign paroxysmal positional
vertigo that is disabling and refractory to all positioning treatments can be managed
surgically, though this is rarely necessary.
Figure 5 Canalith repositioning maneuver. Step 1: Seat the patient on a table positioned so
they may be taken back to the head hanging position with the neck in slight extension.
Stabilize the head with your hands and move the head 45 degrees toward the side you
will test. Move the head, neck and shoulders together to avoid neck strain or forced
hyperextension. Step 2: Observe for nystagmus and hold the position for ~10 seconds
after it stops. Step 3: Keeping the head tilted back in slight hyperextension, turn
the head ~90 degrees toward the opposite side and wait 20 seconds. Step 4: Roll the
patient all the way on to his or her side and wait 10 to 15 seconds. Step 5: From
this side-lying position, turn the head to face the ground and hold it there 10 to15
seconds. Step 6: Keeping the head somewhat in the same position, have them sit up
then straighten the head. Hold on to the patient for a moment because some patients
feel a sudden but very brief tilt when sitting up. REPEAT: After waiting 30 seconds
or so, repeat the whole maneuver. If there is not paroxysmal nystagmus or symptoms
during Dix–Hallpike positioning (Steps 1, 2) then there is a high likelihood of success.
(Reprinted with permission from Barrow Neurological Institute.)
Figure 6 Semont liberatory maneuver. Step 1: Start with the patient sitting on a table or
flat surface with head turned away from the affected side. Step 2: Quickly put the
patient into the side-lying position, toward the affected side with the head turned
up. Nystagmus will occur shortly after arriving at the side-lying position. Keep the
patient here until at least 20 seconds after all nystagmus has ceased. Step 3: Quickly
move the patient back up and through the sitting position so that he or she is in
the opposite side-lying position with head facing down (head did not turn during the
position change). Keep the patient in this position for ~30 seconds (some recommend
up to 10 minutes). Step 4: At a normal or slow rate, bring the patient back up to
the sitting position. (Reprinted with permission from Barrow Neurological Institute.)
Benign paroxysmal positional vertigo is a mechanically based disorder best managed
by a mechanical remedy. Vestibular suppressants such as meclizine or diazepam may
have a role in premedicating those patients with severe motion sickness, but are generally
not helpful for BPPV because the episodes are brief and because the therapeutic maneuvers
are so immediate and effective.
Self-treatment of BPPV
Patients given instructions for self-administered canalith repositioning treatment
at home show improvement that is superior to that seen on those given self-administered
Brandt–Daroff exercises.[25] Home exercises seem to pose little risk for most patients, and may be a useful adjunct
to treatment, but is probably somewhat less effective than treatment administered
by an experienced clinician.[26]
Treating Lateral Canal BPPV
Lateral canal BPPV is often unresponsive to canalith repositioning designed to treat
posterior canal BPPV,[17]
[27]
[28] but may respond to any of a variety of other maneuvers intended to move canaliths
from the lateral canal into the vestibule. The best treatment for horizontal canal
BPPV remains unclear. The most commonly used treatment in the published literature
is the roll maneuver (Lempert maneuver or barbecue roll maneuver) (Fig. [7]) or similar variations.[12]
[13]
[17]
[23]
[28]
[29]
[30]
[31]
[32]
[33] The effectiveness of the roll maneuver in treating lateral canal BPPV appears to
be <75%,[13]
[33] although reported response rates vary from near 50% to almost 100%. An overview
of some of the other treatments for horizontal canal BPPV are discussed elsewhere.[13]
[31] At this time, there is insufficient evidence to support the use of any particular
maneuver over another for lateral canal BPPV treatment.[24]
Figure 7 Lempert 360- (Barbeque) degree roll maneuver to treat horizontal canal BPPV. When
the patient's head is positioned with the affected ear down, the head is then turned
quickly 90 degrees toward the unaffected side (face up). A series of 90-degree turns
toward the unaffected side is then undertaken sequentially until the patient has turned
360 degrees and is back to the affected ear-down position. From there, the patient
is turned to the face-up position and then brought up to the sitting position. The
successive head turns can be done in 15- to 20-second intervals even when the nystagmus
continues. Waiting longer does no harm, but may lead to the patient developing nausea,
and the shorter interval does not appear to detract from the effectiveness of the
treatment. (Reprinted with permission from Barrow Neurological Institute.)
The treatment of horizontal canal BPPV depends on knowing the affected side, which
is not always obvious. If the horizontal canal BPPV occurs after treatment for posterior
canal BPPV, then the affected ear is likely to be the same one that had been affected
by the posterior canal BPPV. As mentioned earlier, the side with the strongest nystagmus
from the supine head turning test (Fig. [4]) is usually assumed to be the affected side. Nevertheless, in some cases the affected
side is unclear, and one must simply choose one side.
Posttreatment Restrictions
Over the years there have been various recommendations, such as wearing a cervical
collar or sleeping upright following treatments. A recent review found there was little
difference in outcome between those given posttreatment restrictions and those receiving
no instructions or restrictions.[24] At this point, evidence is lacking to recommend postmaneuver restrictions in patients
treated with canalith repositioning therapies, although there is generally no associated
harm associated with these instructions.
Complications
The most common complications include nausea, vomiting, fainting, and conversion to
lateral canal BPPV during the course of treatment due to “canal switch” that occurs
~6% of the time,[27]
[34] underscoring the importance of recognizing the lateral canal variant of BPPV. Patients
with unstable cervical spine injury or who may not safely have their head moved should
have treatment deferred, but there are otherwise no contraindications.
PROGNOSIS
PROGNOSIS
At present, the generally accepted recurrence rate of BPPV after successful treatment
is 40 to 50% at 5 years of average follow up.[35]
[36] There does appear to be a subset of individuals prone to multiple recurrences.
