Benign Paroxysmal Positional Vertigo (BPPV)

What is BPPV and How Common is It? 

Benign Paroxysmal Positional Vertigo (BPPV) is the most common cause of vertigo. Below is an explanation of each word in the diagnosis:

• Benign: means “not dangerous”, in the sense that’s it’s not associated with any serious medical causes and that’s easily treated
• Paroxysmal: means that the symptoms occur very suddenly and are very intense, but typically brief 
• Positional: means that the symptoms are only triggered by certain head movements 
• Vertigo: means that the dizziness is spinning in nature (as opposed to other types of dizziness where you feel swaying or rocking).

How common is it? Let’s talk numbers

• BPPV accounts for approximately 25% of all clinical types of vertigo and 60% of peripheral vertigo cases.

• It is estimated that 2.4% of people will experience BPPV at some point in their life. This is what we call “lifetime prevalence”.

• Approximately 1.6% of the population will suffer from BPPV every given year. This is what we call “1-year prevalence”.

Age and Sex Distribution

• BPPV shows a preference for older adults, with an average age of onset between 51-57 years.

• It is rarely observed in individuals younger than 35 years without a history of head trauma.

• Women are more commonly affected, accounting for about 64% of cases.

What are the “crystals” in BPPV

The "crystals" involved in BPPV are tiny calcium carbonate particles called otoconia. Normally, these crystals are attached to gelatinous membrane in the utricle of the inner ear. The utricle is the gravity sensor of the inner ear, and it uses the weight of these otoconia to detect changes in gravity.

In BPPV, these otoconia become dislodged from the utricle and migrate into the fluid-filled semicircular canals, another part of the inner ear (that detects changes in rotational acceleration). This is possible because the utricle and semicircular canals are connected. There are 3 canals, but the posterior semicircular canal is the most commonly affected.

When the head moves in certain positions, these loose and floating crystals will move in the fluid of the semicircular canal, stimulating the nerve receptors of that balance canal. This sends false signals to the brain that there is a head rotation, resulting in the characteristic vertigo of BPPV.

Why Does Someone Get BPPV? (Why do the crystals dislodge)

As we just saw, BPPV occurs when calcium carbonate crystals, called otoconia, become dislodged from their normal location in the utricle of the inner ear and migrate into the semicircular canals. While the exact reason for this dislodgement isn't always clear, several factors have been identified as potential causes:

1. Aging: The natural degeneration of the vestibular system in the inner ear due to aging is a common cause of BPPV.

2. Head Trauma Injuries to the head can cause otoconia to break loose and enter the semicircular canals.

3. Inner Ear Disorders: Damage caused by other inner ear conditions, such as vestibular neuritis or Menière's disease, can lead to BPPV. When the nerve fibers that connect to the utricle degenerate (because of neuritis for example), the neurons that were supplied by those fibers will die, and the otoconia connected to those will dislodge and float.

4. Prolonged Bed Rest: Extended periods of inactivity, such as during illness or after surgery, may increase the risk of otoconia becoming dislodged.

5. Osteoporosis: Some studies suggest a link between osteoporosis and an increased risk of BPPV, possibly due to changes in calcium metabolism.

6. Migraine: There appears to be an association between a history of migraines and the development of BPPV.

7. Vascular Factors: Conditions such as high blood pressure, high cholesterol, and history of stroke have been linked to an increased risk of BPPV. This is more an association that a direct cause. 

8. Vitamin D Deficiency: Has been identified as a significant risk factor for both the development and recurrence of BPPV. Low levels of vitamin D may impair calcium metabolism in the inner ear, leading to weakened otoconia that are more likely to dislodge. Studies have shown that supplementing vitamin D in individuals with deficiency can reduce the recurrence rate of BPPV episodes and decrease the frequency of relapses over time

It's important to note that in many cases, the exact cause of BPPV remains idiopathic, meaning no specific cause can be identified. The condition can occur spontaneously, especially in older adults, without any clear triggering event or underlying condition.

Symptoms of BPPV

If you have BPPV, you might experience:

1. A true spinning vertigo sensation (not rocking or swaying)
   
   

2. The episodes are short (usually less than a minute)

3. They are triggered by changes in head position: when lying down, turning over in bed, or looking up

4. The episodes are frequently associated with nausea and sometimes vomiting

5. Difficulty with balance and walking that can last a few hours after the spinning vertigo. This would be a temporary feeling. It the balance issues persist, it would be not be caused by BPPV and another cause must be considered.

It's important to note that BPPV does NOT cause hearing loss or ringing in the ears (tinnitus).

Types of BPPV

Yes, there is more than one type of BPPV! There are 3 semicircular canals, and each canal can be affected by the floating otoconia leading to BPPV:

1. Posterior Canal BPPV: This is the most common type, accounting for close to 90% of cases. It typically causes vertical upward and rotatory nystagmus (involuntary eye “jumping” movements) during the Dix-Hallpike test.
   
   
2. Horizontal Canal BPPV: Occurring in 5-10% of cases, this type often causes symptoms when turning the head from side to side while lying down. The episodes, although they share symptoms with the posterior type of BPPV, tend to last longer.
   
   
3. Superior (or Anterior) Canal BPPV: The rarest form (around 1% of cases). The vertigo can be more intense and last longer. It’s also harder to diagnose and treat. 

How to Diagnose BPPV

The primary diagnostic tool for posterior and superior BPPV is the Dix-Hallpike maneuver. This test will trigger vertigo, confirming the diagnosis. The Dix-Hallpike test has an accuracy rate of over 90%. Here's a more detailed description of the process:

1. The patient sits on an exam table with their legs extended.
2. The examiner turns the patient's head 45 degrees to one side.
3. The patient is quickly lowered backward, with their head hanging slightly off the edge of the table.
4. The examiner observes the patient's eyes for characteristic nystagmus (jerking eye movements). The nystagmus will be different depending on if the posterior canal is involved or if the superior canal is involved. 

For the horizontal BPPV, the maneuver is called the Supine Roll. Here are the steps:

1. Patient lies on his back with head flexed 30 degrees (chin towards chest)
2. Head is quickly rotated 90 degrees to one side
3. Observe for nystagmus (typically within 5-20 seconds, lasting up to 60 seconds)
4. Return head to center
5. Repeat rotation to opposite side
6. Observe nystagmus pattern to determine affected side

While the clinical evaluation is usually sufficient, additional tests may be necessary IF the symptoms do not respond to the usual treatment, the vertigo is not typical, the symptoms last longer than usual or they are associated with neurological symptoms. In those situations, it is important to investigate for other conditions, including disorders of the central nervous system. A hearing test (audiogram) and balance tests (VNG, vHIT and/or VEMP) may be ordered. A detailed neurological examination would be indicated, in addition to imaging studies (CT scan or MRI of the brain).

Treatment for BPPV

It is important to understand that BPPV is highly treatable. The main approaches include:

1. Vestibular Physiotherapy:

This is the primary treatment, involving specific repositioning maneuvers. The goal is to bring the crystals back in the utricle where they belong. This is possible by moving the head and body in a particular sequence of steps. This treatment is sufficient in over 90% of patients.

• Epley or Semont maneuver for the posterior canal
• BBQ roll for the horizontal canal
• Deep head hanging or Yacovino maneuver for the superior canal

A single maneuver has an efficacy of 80-100%. While some patients may be entirely cured after one session, it’s common for individuals to need another session 2-3 weeks later. I then advise my patients to resume physiotherapy at every relapse of symptoms. It’s not uncommon for individuals who suffered from BPPV for years to require sessions at a monthly interval for 4-6 months. The most important thing to remember is that BPPV is entirely curable.

2. Medical Treatment:

Most doctors (including myself) will now recommend vitamin D supplements, especially for deficient patients, as vitamin D deficiency has been identified as a risk factor for BPPV developement and recurrence. Studies have shown that the 1000 U (units) daily dose is not sufficient, and that the weekly dose of 10 000 U should be prescribed.

3. Surgical Treatment:

Rarely needed, but might be considered in severe, persistent cases that don't respond to other treatments. I would only recommend surgery after I’ve performed myself at least 3 repositioning maneuvers on my patient, and after at least 6-12 months of aggressive physiotherapy and Vitamin D supplementation.

The most common surgery performed (and the one I would recommend for those patients) for posterior canal BPPV is called posterior canal occlusion. In short, the mastoid bone (part of the skull) must be drilled to reveal the bone covering the posterior semicircular canal. The canal is then gently drilled open and the lumen of the canal (the fluid filled compartment) is plugged with bone dust. The plugging (occlusion) forms a blockage in the circulation of the fluid in the canal, which prevents the otoconia from floating around and causing vertigo. The surgery is over 90% successful. The most important risk associated with this surgery (although still rare) would be hearing loss, since we have to open the inner ear to block the canal.

Recurrence and Prevention

BPPV has a recurrence rate of about 50% within 5 years. However, there are preventive measures that patients can take. A simple one would be to avoid quick head movements. Another consideration, given what we’ve discussed in the sections above, would be to ensure proper Vitamin D levels.

It is also possible for patients to perform their own regular repositioning exercises at home. I would only recommend performing self-repositioning maneuvre after a qualified healthcare provider has shown the patient or relative how to safely perform the maneuvre at home. This is because an incorrectly performed maneuvre can make things worse! For example, it can convert a posterior canal BPPV into a horizontal or superior canal BPPV. In addition to being shown how to properly do the Epley maneuvre at home, a device called Dizzy-Fix can help patients perform the Epley maneuvre with the correct steps and at the right speed.