Benign Paroxysmal Positional Vertigo (BPPV)
Summary of a public talk given at a BC Balance and Dizziness Disorders Society (BADD) meeting at St. Paul’s Hospital in Vancouver on March 20, 2013.
Speaker: Dr. Jane Lea. Dr. Lea completed medical school at the University of Toronto (UofT). Her five-year residency in Otolaryngology-Head & Neck Surgery at UofT was followed by sub-specialty fellowship training in Otology/Neurotology and Pediatric Otolaryngology at the University of British Columbia (UBC). Dr. Lea completed further training abroad at Johns Hopkins (Baltimore, USA) and Royal Prince Alfred Hospital (Sydney, Australia) with a focus on vestibular disorders. Her current clinical practice at St. Paul’s, Vancouver General and BC Children’s Hospitals focuses on disorders of the ear and its related nervous system.
Benign paroxysmal positional vertigo (BPPV) is an inner ear problem. It is defined as sudden attacks of vertigo that last for seconds and usually provoked by certain head positions. First described in 1921, BPPV is by far the most common cause of vertigo. 2.4% of the population will have BPPV during their lifetime. Though that may not sound like a lot of people, in terms of the population it is. In Germany, for example, about a million people have this disorder each year.
The bedside positioning manoeuvres for BPPV are very successful – about 80 to 90 percent – and usually one treatment is enough. ~ Dr. Jane Lea
“Benign” means it is not fatal or life-threatening. “Paroxysmal” means it comes and goes quite quickly. The dizziness usually lasts less than 60 seconds and usually occurs in bouts. You may have a lot of vertigo for several weeks and then it goes away; then it will reoccur several months later. If you get BPPV once, you’re likely to get it again, but when is not known. “Positional” (sometimes the term “positioning” is used) means it occurs with certain head positions, most often by reaching up or down to find something or rolling from one side to the other in bed. “Vertigo” means that it is a spinning sensation, rather than feeling light-headed or woozy.
Risk factors for BPPV
The following make you prone to having BPPV:
- ear surgery
- head injuries
- jarring activities such as heading a soccer ball
- ear infections
- other ear disorders such as Ménière’s disease;
- medications that damage the ear;
- unusual head positions, for example leaning your head back for a long time at the dentist or hair dresser.
Most cases of BPPV are idiopathic, meaning the cause is unknown.
Causes of BPPV
The inner ear houses the snail-like organ of hearing (cochlea), as well as the organs of balance (utricle, saccule and three semicircular canals). The utricle responds to gravity and tells your brain whether you are moving up or down, to the right or left, or backwards or forwards. This gravity receptor area houses little stones (otoconia) on a gelatinous membrane. The canals lie at 90 degrees to one another and there is a mirror image on the other side of your head. The horizontal canal sits parallel to the floor, the posterior at the back and the anterior at the top.
The canals detect rotational movement and determine acceleration. They contain fluid and have tiny hair cells at the end area. In effect, the eyes are slaves to the vestibular system. As the fluid moves, the hair cells move, activating nerves that connect to the brain and tell the eyes what to do. Imagine turning a coffee mug; when you turn it to the right, the fluid moves to the left. This is similar to what happens in the canals. For example, if you turn your head to the left quickly, the canals on that side send a message to the brain saying, “You’ve moved your head to the left, so you need to move your eyes an equal amount to the right.”
Diagnosis of BPPV
Sometimes trauma or viral illnesses can cause the stones to come loose from the utricle and fall into one of the canals. The stones become either free-floating particles (canalithiasis) or they get stuck on a little hinged area of the canal (cupulolithiasis). Diagnosis of BPPV is purely clinical.
An examiner, physician or physiotherapist puts your head through a series of movements called the Dix-Hallpike manoeuvre; this causes the particles in the canal to move. As they fall downwards into the canal, fluid is pulled along. This activates the receptors in the posterior canal, causing your eyeballs to move quickly (nystagmus) and making you feel as though you’re spinning.
The examiner will observe your eye movements and ask how you are feeling. The direction of your eye movements are used as a clue to diagnosing which canal contains the stones. As the movement is sometimes very rapid, you might be asked to put on special goggles; these connect to a monitor that clearly graphs your eye movements.
When someone is put through the Dix-Hallpike manoeuvre the dizziness and eye movements don’t start right away. The particles must overcome inertia before they start to fall; this is why it usually takes several seconds to become symptomatic when you put your head into a position that provokes vertigo.
When the dizziness starts, it comes on quite suddenly and fades away. The dizziness is brief because the particles eventually find a new home at the end of the canal. At first, the particles move together like a ball; as the manoeuvre is done over and over, the particles disperse and stop working together and you become less symptomatic. When you sit up, your eye movements reverse in direction; this change is a good diagnostic clue.
Treatment options for BPPV
Treatment involves a trained professional moving your head through a series of manoeuvres to return the stones to where they belong. As each canal has a closed “door” at one end, the particles must be moved to the end of the canal that opens. In 80 to 90% of BPPV cases, the stones fall into the bottom (posterior) canal. These are usually successfully treated with particle re-positioning, called the Epley manoeuvre. After the treatment, you’ll be told to sleep on the good ear for a bit, using several pillows to prop your head up. Typically, this helps the particles find a new home and not get dislodged again.
If the Epley manoeuvre is not done perfectly or if the head is lifted up, some of the particles will go backwards or into another canal. That is why it is important for the examiner to watch your eye movements throughout the whole procedure. Sometimes a different and unexpected eye movement is seen; this indicates that the particles have flipped into another canal and a different manoeuvre is needed to fix the problem. And sometimes the Epley manoeuvre gets some of the particles but not all.
Less common variants of BPPV
A minority of patients have less common variants of BPPV. They either have stones in more than one canal or on both sides of their head. These patients are really hard to diagnose and treat. Their eye movements are complicated and it takes a lot of time, expertise and patience to figure out the problem.
The Epley Omniax System, currently unavailable in Canada, is a recently developed device that is great for diagnosing and treating challenging cases involving multiple canals.
Sometimes there are so many particles in the canal it is like a traffic jam – the canal is completely blocked. The expected eye movements are seen only when a skull vibrator is used to start dispersing the particles.
Cupulolithiasis is one variant that is really a challenge to treat and very symptomatic. The eye movements last longer, it is very violent and it doesn’t fatigue. No amount of Epley manoeuvres will move the clump of particles stuck on the hinged area of the canal. In these cases, a skull vibrator is sometimes successfully applied to convert them to free-floating particles, which are easier to treat.
Particles in the horizontal canal are very troublesome for most patients; again, the symptoms are quite violent. They are diagnosed by simply watching your eye movements when you lie down and roll from one side to the other. It is, however, really complicated to determine which ear is involved. It stumps most ENTs because the eye movements are totally different depending on whether the particles are free-floating or stuck to the hinged joint (cupula). By analyzing a graph of the exceptionally rapid eye movements, a sub-specialist can figure out if the left or right ear is involved. The treatment consists of the aptly-named barbecue roll; you are turned round and round as though on a spit. It is unpleasant for many individuals, causing both dizziness and discomfort.
Particles in the anterior canal are frequently inadvertently treated by the patient themselves. Because the particles usually lie up at the top of the head, lying down or sitting up causes them to fall back where they belong. Often patients make themselves better even before they reach the specialist’s office. In some patients, the particles get stuck on the hinged joint and that can be a problem. However the Dix-Hallpike manoeuvre usually fixes this, so many ENTs and physiotherapists are coincidentally fixing the problem during testing.
Some people with BPPV never get better. No matter how many times they are treated they continue to get dizzy. Surgery is occasionally done to plug a canal so it no longer works and causes dizziness; however, particles may fall into the other two canals and start causing dizziness. Blocking a canal is not a common procedure and is only done after every other treatment has been tried. As fluid can leak out when the canal is plugged, patients are at risk of complete hearing loss in that ear.
BPPV and Ménière’s
Canal re-positioning manoeuvres do not work for Ménière’s disease. Ménière’s attacks usually last more than 20 minutes and up to a few hours Ménière’s and BPPV frequently overlap; you can have both. The cause of Ménière’s is not completely understood. In the last several years theories have evolved that Ménière’s may be caused by particles coming from the saccule and, rather than getting lost in the canals as in BPPV, getting lost near the organ of hearing. Some very preliminary work looking at MRI scans of patients that have acute attacks of Ménière’s is being done at St. Paul’s to see if particles can be detected.