Keywords
vestibular lithiasis - multicanalicular - otoconial debris - BPPV - Dix–Hallpike test
- supine head roll test
Introduction
Vestibular lithiasis exists either as free-floating otoconia within the semicircular
canal (SCC) (canalolithiasis) or as otoconial particles getting adherent to the cupula
(cupulolithiasis), thus making it heavy and gravity sensitive. Cupulolithiasis also
exists in two forms, with the otoconial particles getting attached either to the canal
side (Cup-C) or to the utricular side (Cup-U) of the cupula. [Table 1] shows that 0 to 21.25% of all patients diagnosed with benign paroxysmal positional
vertigo (BPPV) at any specialty clinic have multicanalicular BPPV.[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11] In multicanalicular BPPV, either there is the involvement of the same SCC on both
sides or simultaneous involvement of different SCCs on the same or both sides. Multicanalicular
BPPV frequently occurs with underlying comorbid conditions like head trauma, labyrinthitis,
Meniere’s disease, and otitis media.[12]
[13]
[14]
[15]
[16]
Table 1
The relative frequencies of different BPPV variants at specialty clinics reported
in various studies
|
Authors
|
No. of patients
|
PSC-BPPV
|
HSC-BPPV
|
ASC-BPPV
|
Multiple canals
|
|
Abbreviations: ASC-BPPV, anterior semicircular canal benign paroxysmal positional
vertigo; HSC-BPPV, horizontal semicircular canal benign paroxysmal positional vertigo;
PSC-BPPV, posterior semicircular canal benign paroxysmal positional vertigo.
|
|
De la Meilleure et al,[1] 1996
|
287
|
78.05%
|
16.38%
|
–
|
5.57%
|
|
Honrubia et al,[2] 1999
|
292
|
85.62%
|
5.14%
|
1.37%
|
7.87%
|
|
Macias et al,[3] 2000
|
259
|
93.02%
|
1.94%
|
–
|
5.04%
|
|
Korres et al,[4] 2002
|
122
|
90.16%
|
8.2%
|
1.64%
|
–
|
|
Sakaida et al,[5] 2003
|
50
|
56%
|
38%
|
|
6%
|
|
Imai et al,[6] 2005
|
108
|
64.82%
|
33.33%
|
–
|
1.85%
|
|
Nakayama and Epley,[7] 2005
|
833
|
66.39%
|
10.08%
|
2.28%
|
21.25%
|
|
Cakir et al,[8] 2006
|
169
|
85.21%
|
11.83%
|
1.18%
|
1.78%
|
|
Moon et al,[9] 2006
|
1,692
|
60.9%
|
31.9%
|
2.2%
|
5.0%
|
|
Jackson et al,[10] 2007
|
260
|
66.9%
|
11.9%
|
21.2%
|
–
|
|
Chung et al,[11] 2009
|
589
|
61.8%
|
35.3%
|
2.9%
|
–
|
Multicanalicular BPPV has been subclassified as under:[13]
-
Single-canal bilateral involving the same SCC in either of the labyrinths.
-
Multicanal unilateral involving at least two different SCCs (posterior, lateral, or anterior) in one of
the labyrinths.
-
Multicanal bilateral involving two or more different SCCs in both labyrinths.
Multicanalicular BPPV is unilateral in two-thirds of the cases, bilateral in the other
one-third of the cases, and roughly 80 to 90% of these patients have simultaneous
involvement of posterior (PSC) and horizontal semicircular canal (HSC) of the same
or opposite side.[13]
[17] A mixed geotropic-horizontal and upbeating nystagmus with a disproportionately large
geotropic-torsional component toward the lowermost ear either in the Dix–Hallpike
or supine roll test is indicative multicanalicular BPPV, affected with concurrent
posterior and horizontal semicircular canalolithiasis.[18] However, in a study of 20 patients diagnosed with monocanalicular horizontal semicircular
canalolithiasis, the use of three-dimensional video-oculography demonstrated a vertical
component in 15 (75%) and a torsional component in 19 (95%) patients.[19] The variant single-canal bilateral BPPV involving anterior SCCs is a difficult-to-diagnose condition because the lateralizing
torsional component of positional downbeat nystagmus is often inconspicuous or absent.
Bilateral HSC-BPPV, with its various possible permutation and combinations of canalolithiasis
and cupulolithiasis on either side, is also potentially difficult to diagnose. Likewise,
in the PSC-BPPV, although the Dix–Hallpike test might be positive bilaterally, the
disease is likely to be bilateral only if there is a torsional component clockwise
on one side and counterclockwise on the other.[20]
The positional maneuvers, namely Dix–Hallpike maneuver for the vertical canals (PSC
and anterior SCCs) and supine roll test for the HSCs, need to be meticulously performed
on both sides in all cases of BPPV (idiopathic as well posttraumatic). The Dix–Hallpike
maneuver is considered specific for the diagnosis of the PSC-BPPV, but in as many
as 80% of cases, it may elicit the positional nystagmus of HSC-BPPV as well.[21] The elicited positional nystagmus localizes the involved SCC as per the Ewald’s
first law, which states that the vestibular nystagmus is always directed parallel
to the plane of the stimulated canal.[22] The variations in the geometry of SCC among individuals might be responsible for
the elicitation of positional nystagmus of the HSC during the Dix–Hallpike test. Therefore,
it is imperative to carry out the supine roll test with 30 degrees of cervical flexion
in all cases of suspected BPPV, where the Dix–Hallpike maneuver to either of the sides
has failed to elicit any positional nystagmus.[23] Video recording of diagnostic positional test and replaying it on the bigger screen
of the computer to localize and lateralize the involved SCC is useful to increase
the diagnostic accuracy in the cases diagnosed with vestibular lithiasis.[19]
I am reporting here a very unusual case of right unilateral multicanalicular vestibular
lithiasis of PSC and HSC, in which a single supine head roll test elicited three different
patterns of nystagmus and all with significant localizing values. The author was able
to video record the diagnostic supine head roll test.
Case Description
History
A 70-year-old male presented with 1 day history of vertigo on lying supine, getting
up from supine, and on assuming either of the lateral recumbent positions. There was
no history of staggering, diplopia, dysarthria, difficulty in swallowing, hiccups,
drooping of upper eyelids, or facial or limb weakness. There was also no history of
hypertension, diabetes, coronary artery disease, hypothyroidism, jaundice, craniocervical
trauma, cervical radiculopathies, cervical canal stenosis, rheumatoid arthritis, Paget’s
disease, ankylosing spondylitis, low back dysfunction, spinal cord injuries, or cerebrovascular
disease.
Examination
The general physical examination and vitals of the patient were normal. The screening
examination of the cervical spine did not reveal any limitation of movement. The examination
of the back region did not reveal kyphoscoliosis. The examination of the lumbosacral
spine, including straight-leg raising (SLR) test and reverse SLR test, were normal.
The neurological examination revealed normal cranial nerve examination; strength was
grade 5/5 in all four limbs with normal deep tendon reflexes, and bilateral plantar
reflexes were flexor. The examination of the cerebellar system revealed no spontaneous
or gaze-evoked nystagmus, and there was no appendicular or axial incoordination. The
otoneurological examination revealed normal vertical and horizontal saccadic and smooth
pursuit eye movements. The head impulse test was bilaterally normal.
Before carrying out positional tests, the presence of spontaneous nystagmus was ruled
out by using takeaway Frenzel goggles.[24] The Dix–Hallpike test was carried as per the published guidelines of the American
Academy of Otolaryngology, Head, and Neck Surgery Foundation.[23] The patient was positioned on the examination table in long-sitting, in a manner
that his right side was toward its long free edge, and the distance of his bottoms
from the head end of table allowed his head to hang as he was taken to the Dix–Hallpike
position. The patient’s head was held with both hands and was rotated 45 degrees to
his right in the yaw plane. Thereupon, he was laid in such a manner that his 45 degrees
right-rotated head was extended 20 degrees on the support of the author’s hands to
represent the right Dix–Hallpike position. In the right Dix–Hallpike position, the
patient’s head was maintained for 60 seconds. As the right Dix–Hallpike position did
not elicit positional nystagmus, he was positioned to the upright sitting to repeat
the identical sequence of events on the left side. The left Dix–Hallpike positioning
also did not elicit positional nystagmus during the 60 seconds of observation in the
head hanging position. The supine roll test was performed with the patient in the
long sitting on the examination table. He was positioned supine with his head landing
on a four-inch-thick pillow, so it got anteflexed to approximately 30 degrees in this
position. A horizontal lying-down nystagmus (LDN) beating to the patient’s left was
observed that lasted for 23 seconds. After waiting for 30 seconds, his head was briskly
rotated first to his right, which elicited after a latency of 5 seconds, a counterclockwise
torsional (from examiner’s perspective) upbeating positional nystagmus lasting approximately
23 seconds. Subsequently, the patient’s head was brought to the neutral supine position
and then briskly rotated to his left, which after a latency of 2 seconds, elicited
a geotropic horizontal positional nystagmus lasting 15 seconds. The supine head roll
test repeated to the right elicited after a latency of 2 seconds, a stronger geotropic
horizontal positional nystagmus. The accompanying rotational vertigo during the supine
roll test was more severe during the elicitation of horizontal nystagmi. Three different
elicited patterns of nystagmus during a single supine head roll test localized the
disease to the right HSC and PSC ([
Video 1
]). Video-oculography was not utilized during the positional tests.
Video 1With the patient in the long sitting on the examination table, he was positioned supine
with his head landing on a four-inch-thick pillow, so it anteflexed to ~30 degrees
in this position. A horizontal lying-down nystagmus (LDN) beating to the patient’s
left was observed that lasted for 23 seconds. After waiting for 30 seconds, his head
was briskly rolled first to his right, which elicited after a latency of 5 seconds,
a counterclockwise torsional (from examiner’s perspective) upbeating positional nystagmus
lasting approximately 23 seconds. Subsequently, the patient’s head was brought to
the neutral supine position and then briskly rolled to his left, which after a latency
of 2 seconds, elicited a geotropic horizontal positional nystagmus lasting 15 seconds.
The supine head roll test repeated to the right elicited after a latency of 2 seconds,
a stronger geotropic horizontal positional nystagmus.
Diagnosis
The aforesaid clinical history and otoneurologic examination are consistent with the
diagnosis unilateral multicanalicular be BPPV involving right-sided HSC and PSC. Video
recording of the initial supine head roll test ([
Video 1
]), not only facilitated the identification of upbeating positional nystagmus (and
hence localization to the involved PSC) but also captured a stronger horizontal geotropic
nystagmus to the right (compared with the left) on repeating the supine head roll
test to the right. The initial LDN to the left, captured during the video recording
of the supine roll test, is also supportive of lateralization to the geotropic right
horizontal semicircular canalolithiasis. The video recording of the supine head roll
test was observed several times on a bigger screen of the computer to identify the
stronger horizontal geotropic nystagmus, and hence the involved right HSC and PSC.
Intervention
The patient was initially treated with Gufoni maneuver[25]
[26]
[27] consecutively twice in one session for a total of two sessions at an interval of
1 hour, with the verifying supine roll test performed 1 hour after the second sequence
of the maneuver. The Gufoni maneuver for the right geotropic HSC-BPPV was performed
by making the patient sit on the edge of the examination table with both lower limbs
dangling down and briskly moving the patient from sitting to the left (contralesional)
lateral recumbent position and maintaining the latter position for 1 minute. Thereafter,
the patient’s head was rotated approximately 45 degrees downwards in the yaw plane
and maintained for 2 minutes, after which he was taken to the upright sitting position.
During the verifying supine roll test performed an hour after each treatment session
with Gufoni maneuver, neither the geotropic positional nystagmus nor vertigo disappeared;
Gufoni maneuver was deemed ineffective and abandoned thereof. Consequently, the right
horizontal semicircular canalolithiasis was treated with barbecue roll maneuver ([Video 2]).[28] The patient was first positioned to the right lateral recumbent, for approximately
30 seconds. Thereupon, he was rolled consecutively toward his uninvolved left side,
maintaining 30 seconds each in the supine, left lateral, prone, and finally right
lateral recumbent positions. After completing one barbecue roll, the patient was positioned
upright sitting with lower limbs dangling down the long axis of the examination table.
Barbecue roll maneuver was performed six times consecutively (until two successive
maneuvers were free of horizontal geotropic nystagmus during its right and left lateral
recumbent positions). The patient had vomited twice during the barbecue roll maneuver
and he was reassured about this. Supine head roll test was repeated an hour after
the treatment session with barbecue roll maneuver. During the repeat supine head roll
test, there appeared a counterclockwise torsional (from examiner’s perspective) upbeating
positional nystagmus after a latency of 6 seconds which lasted for 23 seconds ([Video 3]). LDN and geotropic horizontal positional nystagmus were conspicuously absent implying
successful treatment of right horizontal semicircular canalolithiasis. For the residual
right posterior semicircular canalolithiasis, the patient was treated with five consecutive
modified right Epley maneuvers (EM) on the following day. The modified right EM (r-MEM) was performed with the patient in the long-sitting on the examination table.
A four-inch-thick pillow was placed behind his buttocks as a vantage point instead
of using the end edge of the treatment table during the r-MEM.[29] His head was rotated 45 degrees to the ipsilesional right side in the yaw axis and
he was positioned supine so that his head was in 20 degrees of extension as the cervical
rotation was maintained (position one). During such positioning, upbeating counterclockwise
torsional nystagmus was elicited for less than a minute, with the patient experiencing
concomitant vertigo for the same duration. Upon completion of 1 minute with 45 degrees
of cervical rotation to the ipsilesional right side, the head was rotated 90 degrees
to his left, maintaining its 20 degrees extension (position two). Positioning with
45 degrees of cervical rotation to the contralesional left side with the neck in 20
degrees of the extension, was maintained for 1 minute; patient neither complained
of vertigo nor had any nystagmus during this period. Thereupon, he was instructed
to assume the left lateral recumbent position and rotate his head further leftward
so that his nose was positioned almost right-angled with the treatment table (position
three). The latter position was maintained for 1 minute. Thereupon, he was instructed
to sequentially dangle down his lower limbs along the free edge of the examination
table, and while maintaining the head position, he was assisted to assume an upright
sitting position completing one r-MEM. No vertigo complaint was made by the patient either in the nose-down left lateral
recumbent position or on assuming the upright position after r-MEM completion. A total of five r-MEM were performed, with identical positional nystagmus getting elicited in position
one with concurrent vertigo during the first two r-MEM. In the third sequence of r-MEM, an upbeating nystagmus was observed during position one as well three, and on
assuming the upright sitting position, the patient had a severe bout of vertigo with
severe anteropulsion. During the fourth and fifth r-MEM, neither nystagmus was observed nor vertigo was complained by the patient.
Video 2The patient is first positioned right lateral recumbent, for ~30 seconds. Thereupon,
he is rolled consecutively toward his uninvolved left side, maintaining 30 seconds
each in the supine, left lateral, prone, and finally right lateral recumbent positions.
After completing one barbecue roll, the patient is positioned to the upright sitting
with lower limbs dangling down the long axis of the examination table.
Video 3The supine head roll test is repeated after 1 hour of the therapeutic session with
barbecue roll maneuver. When the head is yawed maximally to the right, there appears
a counterclockwise torsional (from examiner’s perspective) upbeating positional nystagmus
after a latency of 6 seconds which lasted 23 seconds.
Prognosis and Outcome
A supine roll test done 20 hours after r-MEM did not elicit any positional nystagmus. The patient neither complained of rotational
vertigo or any nonvertiginous dizziness. He was telephonically questioned weekly regarding
the recurrence of rotational vertigo for the next 4 weeks, and it was confirmed that
he remained symptom free till then.
Discussion
The otoconia within the SCCs consist of calcite crystals (in canalolithiasis as well
as cupulolithiasis) composed of calcium carbonate derived as broken-off fragments
from the degenerative utricular macula. Usually, only one SCC is affected, and the
monocanalicular posterior semicircular canalolithiasis is by far the most frequently
encountered variant. In the most common variant of unilateral multicanalicular vestibular
lithiasis of PSC and HSC, possibly the otoconia enter both the canals simultaneously.
By contrast, in the second most common variant of bilateral multicanalicular vestibular
lithiasis of PSC and HSC, it is reasonable to think that the PSC-BPPV develops first
on one side; this probably alters the habitual sleeping position of the sufferer to
the unaffected lateral recumbent that sequentially leads to contralateral horizontal
semicircular canalolithiasis.
The case of unilateral multicanalicular vestibular lithiasis of PSC and HSCs presented
here is unusual for three reasons.
First, the clinical settings like preceding history of head trauma or underlying otologic
conditions like labyrinthitis, Meniere’s disease, and otitis media that predispose
to the development of multicanalicular vestibular lithiasis were distinctly lacking
in this case.
Second, a single supine head roll test elicited three different patterns of nystagmus
(all with significant localizing values), namely horizontal LDN (to patient’s left),
an upbeating counterclockwise torsional (from examiner’s perspective) positional nystagmus
on the initial supine head roll to the patient’s right, and asymmetrically strong
(right more than left) geotropic horizontal positional nystagmus on the subsequent
supine head roll to the patient’s right as well as left. Elicitation of upbeating
geotropic counterclockwise (from examiner’s perspective) torsional nystagmus during
the supine head roll test and not by the Dix–Hallpike test is rather unusual. Perhaps
this could be due to otoconia adhering to the wall of the SCC or the individual variations
in the anatomy of SCCs. Typically, when the head is yawed maximally to the right ([Fig. 1C]) during the supine roll test, the otoconial debris within the long (posterior) arm
of the right HSC falls toward the ampulla ([Fig. 1D]), eliciting a strong right beating horizontal positional nystagmus as per Ewald’s
second law. However, at the same time, the cohabitating otoconial debris within the
ampullary arm of the right PSC is also moving ampullofugal ([Fig. 1D]) under the effect of gravity and an upbeating geotropic counterclockwise (from examiner’s
perspective) torsional nystagmus is anticipated as per the Ewald’s third law. The
elicited positional nystagmus at one point of time is the result of the net effect
of force vectors generated by the otoconial movement in the concurrently involved
right PSC and HSC. This explains two different patterns of the positional nystagmus
elicited during yawing of head maximally to the right during initial and subsequent
positionings in a single supine head roll test.
Fig. 1 (A) Supine neutral position. (B) Orientation of right-sided semicircular canals in the supine neutral position from
the right of the patient. (C) Head yawed to the right during the supine roll test. (D) Orientation of right-sided semicircular canal in the supine neutral position from
the right of the patient, with the head yawed maximally to the right. The otoconial
debris is moved ampullopetal (straight arrow) in the horizontal and ampullofugal (curved arrow) in the posterior semicircular canals.
Third, Gufoni maneuver, despite its proper application in adequate numbers, failed
to resolve the right horizontal canalolithiasis; barbecue roll maneuver successfully
treated the latter. The mastering of an alternative canalith repositioning maneuvers
(CRMs) for each canal, in case of treatment failure with certain maneuvers, is mandatory
for all those who are directly involved in the treatment of multicanalicular vestibular
lithiasis.
The chronological sequencing of treatment with CRM, for the multicanalicular BPPV,
depends on the severity of symptoms attributed to the involved SCC. It is generally
agreed that the HSC is more frequently associated with autonomic symptoms like sweating,
nausea, and vomiting.[30] In cases of multicanalicular canalolithiasis involving PSC and HSC, a reasonable
strategy would be to treat the horizontal semicircular canalolithiasis first and posterior
semicircular canalolithiasis subsequently. The spatial orientation of the involved
SCCs may be taken into consideration for deciding the preferential sequencing for
the treatment with CRM. The PSC slopes inferiorly and has its cupular barrier at a
relatively more dependent end; any otoconial debris that sequestrates in the ampullary
arm of the PSC is liable to remain trapped for a long time. By contrast, the cupular
barrier of the HSC is relatively higher in a location allowing free-floating debris
to easily drift back to the utricle under the effect of gravity. It is, for this reason,
some may prefer to treat posterior semicircular canalolithiasis first as it is believed
to be the reservoir of otoconia.
Conclusion
It is imperative to perform both positional tests, namely Dix–Hallpike maneuver, and
supine head roll test, in cases suspected to have multicanalicular vestibular lithiasis.
The positionings may need to be repeated several times to unveil multiple nystagmi,
each with different localizing and lateralizing values. The clinician handling the
case of multicanalicular vestibular lithiasis needs to realize that the pattern of
nystagmus elicited during positioning in the positional test by stimulation of more
than one SCC is the net effect of force vectors generated by the otoconial movement
in the concurrently affected SCCs. Identifying treatment priorities with CRM for the
individual SCCs is crucial. The canal that is liable to cause severe symptoms needs
early clearance of the otoconial debris. In most cases of multicanalicular horizontal
and posterior semicircular canalolithiasis, the former takes precedence in the order
of priority. If a CRM fails to clear a SCC, an alternative maneuver may need to be
executed. Clinicians involved in the care of cases with multicanalicular vestibular
lithiasis should be well versed with all possible backup maneuvers for clearing each
of the three SCCs.
