Dr. T. Balasubramanian M.S. D.L.O.
Benign paroxysmal positional vertigo is
the most commonly diagnosed vestibular disorder. This is commonly
caused by dysfunction of the posterior semicircular canal. Lateral and
superior semicircular canals can also be involved on rare occasions. It
is characterised by brief spells of severe vertigo (often lasting for
just a few seconds) that are experienced only with specific movements
of the head.
This disorder was first described by
Barany in 1921. He documented the various components of this disorder
as 1. Nystagmus, 2. Fatiguability of the nystagmus and 3. Vertigo. He
failed to correlate the onset of nystagmus with specific positions of
Dix & Hallpike 1952 described the
Dix Hallpike maneuver for eliciting the nystagmus. They also described
the unique features of nystagmus accompanying this disorder. These
features were 1. Very short latency, 2. Directional features, 3. Brief
duration, and 4. Reversibility on returning the patient to a seated
Schuknecht postulated that BPPV was
caused by loose otoconia from the utricle which in certain positions,
displaced the cupula of the posterior canal. (Schuknecht theory). He
later modified his theory and proposed that it was due to the
deposition of otoconia on the cupula of the posterior semicircular
canal. He termed this theory as cupulolithiasis. The cupulolithiasis
theory proposes that calcium deposits become embedded on the cupula
making the posterior semicircular canal sensitive to gravity.
Hall & Ruby suggested that BPPV
could result from deflection of the posterior canal cupula caused by
debris within the posterior canal. This theory became known as the
canal lithiasis theory. In this theory the calcium debris doesnot
become adherent to the cupula but float freely within the canal. Head
movements like looking up, down, or rolling over to the affected ear
may result in the displacement of the sludge causing the classic
Hall & Ruby described 2 types of
BPPV: 1. BPPV with a fatiguable nystagmus, where the deposits are
freely mobile within the cupula of the posterior canal,
2. BPPV with a non fatiguing nystagmus
where the calcium deposits are fixed on the cupula of the posterior
Typical features of BPPV as described by
Hall & Ruby:
1. Canalithiasis mechanism - This
explains the latency of the nystagmus as a result of the time needed
for motion of the material within the posterior canal to be initiated
by the gravity.
2. Duration of the nystagmus - is
correlated with the length of time required for the dense material to
reach the lowest part of the posterior canal.
3. The vertical (upbeating) and
torsional (superior poles of the eye beating towards the lowermost
ear). The nystagmus is more vertical when the patient looks away from
the lowermost ear, and more torsional when looking towards the
4. The reversal of nystagmus when the
patient returns to the sitting position is due to retrograde movement
of material in the lumen of the posterior canal back towards the
ampula, resulting in ampulo petal deflection of the cupula.
5. The fatiguability of the nystagmus
evoked by repeated Dix Hallpike positional testing is explained by
dispersion of material within the canal.
Fig showing anatomy of semicircular canals
is the most common cause of vertigo constituting 20 - 40% of all
patients with peripheral vestibular disease. Mean age of onset ranging
between 4th and 5th decades. women outnumbering men by 2:1.
Patient c/o severe vertigo associated with change in head position.
Symptoms are always sudden in nature, never lasting more than a minute.
The patient may even volunteer provocating postures.
examination: the classic eye movements associated with Dix Hallpike
maneuver is seen.
maneuver: The patient is positioned on the examination table in such a
way that when he/she is placed supine, the head extends over the edge.
The patient is lowered with the head supported and turned 45 degrees to
one or the other side. The eyes are carefully observed; if no abnormal
eye movements are seen, the patient is returned to the upright
same maneuver is repeated with the head in the opposite direction and
the patient's symptoms are noted.
pattern of response consists of the following:
Nystagmus is a combination of vertical upbeating & rotatory
(torsional) beating towards the downward eye. Pure vertical nystagmus
is not seen in BPPV.
There is often a latency of onset of nystagmus
Duration is less than a minute
Vertiginous symptoms are invariably seen
Nystagmus disappears with repeated testing (fatiguability)
Symptoms often recur with the nystagmus in opposite direction on return
of the head to upright position.
involving the posterior canal is the commonest cause of BPPV. Posterior
canal BPPV may rarely be bilateral, but while testing the head must be
positioned in the plane of the posterior canal during testing of
unaffected ear otherwise the debris in the affected side can rest
against the cupula and stimulate an exitatory nystagmus from the
canal has also been identified as the offender in 17 % of cases with
BPPV. Lateral canal BPPV can be detected by a variation of Dix Hallpike
maneuver. The patient's head is first brought to the supine position
resting on the examination table (not hyperextended). The head is then
turned rapidly to the right so that the patient's right ear rests on
the table. The eye movements of the patient are monitored with
Frenzel's glasses for 30 seconds. The patient's head is then turned to
the supine position (eyes looking upward) and is then rapidly turned to
the left so that the left ear rests on the table. Eye movements are
monitored. The nystagmus with lateral canal BPPV is horizontal and may
beat toward (geotropic) or away (ageotropic) from the downward ear. It
begins with a short latency, increases in magnitude progressively, and
is less susceptible to fatigue with repetetive testing than the
vertical torsional nystagmus of posterior canal BPPV.
either alone or in combination with canalithiasis is more likely to be
involved in the etiology of lateral canal BPPV than in the case of
posterior canal BPPV. If the nystagmus is geotropic, the particles are
likely to be in the long arm of the lateral canal relatively far from
the ampulla, if the nystagmus is ageotropic, the particles could be in
the long arm relatively close to the ampulla or on the opposite side of
the cupula either floating within the endolymph or embedded in the
canal BPPV: Incidence of superior canal BPPV is very rare.
electrooculography or 2 dimensional video nystagmography devices donot
record the typical eye movements associated with BPPV. Thus clinical
examination of the patient is of paramount importance.
maneuver: Currently BPPV is managed by repositioning maneuvers that, in
cases of canalithiasis use gravity to move canalith debris out of the
affected semcircular canal and into the vestibule. For posterior canal
BPPV the manuver developed by Epley is effective.
manuver - This is performed by placing the head of the patient in the
Dix Hallpike position that evokes the vertigo. The posterior canal on
the affected side is in the earth vertical plane when the head is in
this position. After the cessation of initial nystagmus, the head is
rolled through 180 degrees, (this is done in two 90 degree increments,
stopping in each position until the nystagmus resolves) to the postion
in which the offending ear is up. The patient is then brought to the
upright sitting postion. This procedure is likely to be successful when
nystagmus of the same direction ccontinues to be elicited in each of
the new position (as the debris continues to move away from the
cupula). This manuver is repeated until no nystagmus is elicited. This
is successful in 90 % of cases. Posterior canal BPPV can be converted
to lateral canal BPPV during Epley manuver. The lateral canal BPPV
resolves in several days. Drugs are usually not prescribed, but low
dose meclizine or calmpose ccan be given 1 hour before the procedure if
the patient is anxious or prone to vomiting.
manuver - is also effective in posterior canal BPPV, but is most
difficult to perform and it has no significant advantages over the
Epley manuver. This is being described here for the sake of completion.
In this manuver the patient is moved quickly in to the position that
provokes the vertigo and remains in that position for 4 minutes. The
patient is then turned rapidly to the opposite side ear down, and
remain in the second position for 4 minutes before slowly getting up.
both these manuvers gravity is the stimulus that move the particles
within the canal, so there is no need to turn the head on the body,
enbloc movement of the head and body as much as possible is the plan.
Figure showing repositioning manuver being performed
physicians use a small hand held vibrator over the mastoid to agitate
the particles and make it move. This mastoid vibrator is to be avoided
in patients with retinal detachment or in patients who may be
susceptible to retinal detachement due to high myopia.
these repositioning manuvers patients are instructed to avoid bending
over and are told to sleep with the head elevated atleast 45 degreees
for the next couple of days.
Doroff exercises - can be performed by the patient in the home
environment. These exercises are performed in 3 sets / day for 2 weeks.
is started like this:
1 - The patient must be seated upright on the bed. Then he moves to
side lying position (position 2) the head is kept angled upwards about
half way. The patient should stay in this position atleast for 30
seconds or till the giddiness subsides. If the giddiness does not
subside thee patient must revert back to position 1. After 30 seconds
the procedure is repeated on the opposite side. Most of the patients
get relief within a period of 10
Fig showing Brandt Doroff exercises
manuvers for lateral canal BPPV:
these patients with geotropic nystagmus lying on one side with the
affected ear up for 12 hours has been found to be effective.
neurectomy - is a very demanding procedure. The posterior canal is
supplied by singular branch of vestibular nerve. This nerve when
preferentially sectioned alleviates the patient's symptom due to
posterior canal BPPV.
canal plugging procedure - is a easier procedure. Through a
mastoidectomy incision the labyrinth is exposed. The posterior canal is
drilled exposing the membranous portion of the canal. The canal is
sealed and packed off thereby preventing the debris from floating.
After the procedure the patient may feel slighlty giddy. The patient
needs to be kept in the hospital till giddiness subsides.
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