What is BPPV??
Benign paroxysmal positional vertigo (
BPPV) is a disorder caused by problems in the
inner ear. Its symptoms are repeated episodes of positional
vertigo, that is, of a spinning sensation caused by changes in the position of the head.
BPPV is the most common cause of vertigo symptoms.
Classification
Vertigo,
a distinct process some people confuse with dizziness, accounts for
about 6 million clinic visits in the U.S. every year, and 17–42% of
these patients eventually are diagnosed with BPPV.
Other causes of vertigo include:
Signs and symptoms
- Symptoms
- Vertigo: Spinning dizziness, which must have a rotational component.
- Short duration (paroxysmal): Lasts only seconds to minutes
- Positional in onset: Can only be induced by a change in position.
- Nausea is often associated
- Visual disturbance: It may be difficult to read or see during an attack due to the associated nystagmus.
- Pre-syncope (feeling faint) or syncope (fainting) is unusual.
- Emesis (vomiting) is uncommon but possible.
- Signs
- Rotatory (torsional) nystagmus, where the top of the eye rotates
towards the affected ear in a beating or twitching fashion, which has a
latency and can be fatigued (if you repeatedly continue placing yourself
in the position to cause vertigo the symptoms should lessen each time).
- Nystagmus should only last for 30 seconds to one minute.
Patients do not experience other neurological deficits such as
numbness or
weakness, and if these symptoms are present, a more serious etiology such as posterior circulation
stroke, must be considered.
The spinning sensation experienced from BPPV is usually triggered by
movement of the head, will have a sudden onset, and can last anywhere
between a few seconds to several minutes. The most common movements
patients report triggering a spinning sensation are tilting their head
upwards in order to look at something, and rolling over in bed.
Cause.
Within the
labyrinth of the inner
ear lie collections of calcium crystals known as
otoconia or otoliths. In patients with BPPV, the otoconia are dislodged from their usual position within the
utricle and they migrate over time into one of the
semicircular canals
(the posterior canal is most commonly affected due to its anatomical
position). When the head is reoriented relative to gravity, the
gravity-dependent movement of the heavier otoconial debris (colloquially
"
ear rocks") within the affected semicircular canal causes abnormal (pathological) fluid
endolymph displacement and a resultant sensation of
vertigo. This more common condition is known as
canalithiasis.
In rare cases, the crystals themselves can adhere to a semicircular canal
cupula
rendering it heavier than the surrounding endolymph. Upon reorientation
of the head relative to gravity, the cupula is weighted down by the
dense particles thereby inducing an immediate and maintained excitation
of semicircular canal
afferent nerves. This condition is termed
cupulolithiasis.
There is evidence in the dental literature that malleting of an
osteotome during closed
sinus floor elevation, otherwise known as
osteotome sinus elevation or
lift,
transmits enough percussive and vibratory forces capable of detaching
otoliths from their normal location and leading to the symptoms of BPPV.
It can be triggered by any action which stimulates the posterior semi-circular canal which may be:
- Tilting the head
- Rolling over in bed
- Looking up or under
- Sudden head motion
- Post head injury
BPPV may be made worse by any number of modifiers which may vary between individuals:
- Changes in barometric pressure - patients often feel symptoms approximately two days before rain or snow
- Lack of sleep (required amount of sleep may vary widely)
- Stress
BPPV is one of the most common vestibular disorders in patients
presenting with dizziness and migraine is implicated in idiopathic
cases. Proposed mechanisms linking the two are genetic factors and
vascular damage to the labyrinth.
Although BPPV can occur at any age, it is most often seen in people over the age of 60.
Besides aging, there are no major risk factors known for developing
BPPV, although previous episodes of trauma to the head or inner ear
infections known as
labyrinthitis, may predispose individuals to future development of BPPV.
Diagnosis
The condition is diagnosed by taking a patient history, and by performing the
Dix-Hallpike maneuver and/or the roll test.
Patients with BPPV will report a history of vertigo as a result of fast
head movements. Many patients are also capable of describing the exact
head movements that provokes their vertigo.
The Dix-Hallpike test is a common test performed by examiners to determine whether the
posterior semicircular canal is involved
. It involves a reorientation of the head to align the posterior semicircular canal (at its entrance to the
ampulla) with the direction of gravity. This test will reproduce vertigo and nystagmus characteristic of posterior canal BPPV.
When performing the
Dix-Hallpike test, patients are descended quickly to a
supine position
with the neck extended by the clinician performing the manoeuvre. For
some patients, this maneuver may not be indicated and a modification may
be needed that also targets the
posterior semicircular canal.
Such patients include those who are too anxious about eliciting the
uncomfortable symptoms of vertigo and those who may not have the range
of motion necessary to comfortably be in a supine position. Obesity can
also present a challenge when performing this assessment. The
modification involves the patient moving from a seated position to
side-lying without their head extending off the examination table, such
as with Dix-Hallpike. The head is rotated 45 degrees away from the side
being tested and the eyes are examined for
nystagmus.
A positive test is indicated by patient report of a reproduction of
vertigo and nystagmus. Both the Dix-Hallpike and the side-lying testing
position have yielded similar results and as such the side-lying
position can be used if the Dix-Hallpike cannot be performed easily.
The roll test can determine whether the
horizontal semicircular canal is involved.
The roll test requires the patient to be in a supine position with
his/her head in 20° of cervical flexion. Then the examiner quickly
rotates the head 90° to the left side, and checks for vertigo and
nystagmus.
This is followed by gently bringing the head back to the starting
position. The examiner then quickly rotates the head 90° to the right
side, and checks for vertigo and nystagmus.
In this roll test, the patient may experience vertigo and nystagmus on
both sides, but rotating towards the affected side will trigger a more
intense vertigo. Similarly, when the head is rotated towards the
affected side, the nystagmus will beat towards the ground and be more
intense.
As mentioned above, both the Dix-Hallpike and roll test provoke the
signs and symptoms in subjects suffering from archetypal BPPV. The signs
and symptoms patients with BPPV experience are typically a short-lived
vertigo, and observed nystagmus. In some patients, though rarely, the
vertigo can persist for years. Assessment of BPPV is best done by a
health professional skilled in management of dizziness disorders, commonly a
physiotherapist,
audiologist or other medical
physician.
The nystagmus associated with BPPV has several important characteristics which differentiate it from other types of nystagmus.
- Positional: the nystagmus occurs only in certain positions
- Latency of onset: there is a 5-10 second delay prior to onset of nystagmus
- Nystagmus lasts for 5–120 seconds
- Visual fixation suppresses nystagmus due to BPPV
- Rotatory/Torsional component is present or (in the case of lateral
canal involvement) the nystagmus beats in either a geotropic (towards
the ground) or ageotropic (away from the ground) fashion
- Repeated stimulation, including via Dix-Hallpike maneuvers, cause the nystagmus to fatigue or disappear temporarily.
Although rare, CNS disorders can sometimes present as BPPV. A
practitioner should be aware that if a patient whose symptoms are
consistent with BPPV, but does not show improvement or resolution after
undergoing different particle repositioning maneuvers, which are
detailed in the Treatment section below, need to have a detailed
neurological assessment and imaging performed to help identify the
pathological condition.
OK LOTS OF INFO TO READ..NEXT ENTRY I'LL SHARE VIDEO OF THE TREATMENT...
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