BENIGN PAROXYSMAL POSITIONAL VERTIGO (BPPV)

If you’ve ever laid down to go to sleep at night, and suddenly found that your room is spinning around you, or that your walls appear to be sliding up and down, you may have experienced Benign Paroxysmal Positional Vertigo (BPPV). BPPV is the most common form of vertigo, and it will be obvious to you if you have it. It is triggered by:

• Getting up
• Laying down
• Rolling over
• Looking up

Although very common, researchers don’t know why it happens to some people and not others. Sometimes it can be triggered by an underlying ear condition but this is not the most common cause.

Benign Paroxysmal Positional Vertigo is a long string of words that defines exactly what it is:

• Benign – it is a non-life threatening condition
• Paroxysmal – short term, the symptoms quickly resolve
• Positional – it only occurs in specific positions
• Vertigo – you see the world spin around you

The Basics

BPPV is a mechanical issue in your inner ear. You can see in the photo below your outer, middle, and inner ear.

The outer ear refers to the part you can see, and the canal that leads toward your ear drum. It helps us hear by catching sound waves and transmitting them to your ear drum so they can reach your hearing organ, the cochlea. Your ear drum, or tympanic membrane, separates the outer ever from the middle ear.

The middle ear is the part inside our ear that regulates pressure. It connects the backside of your ear drum to your throat via the Eustachian tube. This is a vital structure for pressure regulation. At baseline, the Eustachian tube is shut, when you change elevation, or f eel congested, it quickly opens and then shuts again, that open and shut mechanism is what causes your ear to “pop”. Some people can do this on command, it is the same mechanism of pressure regulation. Lastly, deep in our skull, but still connected to our ear, is the inner ear.

The inner ear houses two parts, the first is the vestibular system and the second is the cochlea. The cochlea senses vibrations from your outer ear, tympanic membrane, and ossicles. In turn, it sends a signal to your brain, which perceives the sound, turning it into what you hear. Connected to the cochlea is the vestibular system, this organ senses where your head is in space, and is responsible for your feeling of equilibrium.

The vestibular system, deep in your skull, is where your BPPV comes from. Within your vestibular system, there are a few parts. The first is the utricle and saccule, which are your otolith organs, the second important structure here are the three semicircular canals. These two systems work collaboratively to ensure you know where your head is in space at all times.

The otolith organs contain tiny calcium carbonate crystals, otoconia. Otoconia, often referred to as ‘ear crystals’, detect linear movement. They are “stuck” like rocks on jelly to a gelatinous layer, which is connected to hair cells. When you look down into neck flexion, the otoconia slide forward with gravity, which pull the hair cells forward, and transmit a signal to your brain via your vestibulocochlear nerve. This happens in all directions that would cause rocks to move with gravity. Through this mechanism, always know where our head is in space when moving linearly. Separately, angular movements like twisting, turning, and moving at an angle are detected by the semicircular canals. Three canals, anterior, horizontal, and posterior, detect motion within those planes. When the systems work together, you should always know where your head is in space.

Symptoms

Symptoms of Benign Paroxysmal Positional Vertigo are:

• True room spinning/vertigo
• Vertigo that is only in certain positions & lasting less than 1 minute
• Vertigo sometimes associated with nausea and vomiting.

BPPV is frequently misdiagnosed in those who have other types of vertigo or experience chronic dizziness lasting longer than 1 minute.

Why Do I See The Room Spin?

Semicircular canals don’t just detect and transmit motion signals, they are also responsible for your vestibulo-ocular-reflex, or VOR. VOR is the reflex involved with your keeping objects still while you are moving your head. When the vestibular system is working properly, you can easily look left and right, or up and down, quickly, while keeping your eyes still. You can experiment with this by choosing a spot on the wall to stare at, and turning your head left and right.

VOR is important in order to maintain equilibrium, and our semicircular canals are responsible for making sure it works. When you look left, the fluid in your semicircular canals moves, stimulating the ampulla at the end of the semicircular canal in the plane of movement. That will cause a reflex to be sent through the vestibulocochlear nerve to your brain, to move your eyes in an equal and opposite direction. Then, if you turn back to the right, your eyes will move again, but to the left. This stillness is what keeps our gaze stable when we are walking, and helps us keep our eyes on objects even when we are moving around.

BPPV is what happens when there is an error in the system causing brief spontaneous nystagmus [involuntary eye movement]. The error that occurs is mechanical in nature, your otoconia move off their jelly layer into a semicircular canal. Most often, the otoconia slide into the left or right posterior canal. When this happens, you will experience vertigo that lasts 15-60 seconds and then stops until you move again.

The most irritating times of day will likely be getting up in the morning, or going to bed at night. The act of laying down or rolling over in bed often places the canals in a dependent position. The dependent position will force the crystals to move and stimulate the receptors in the semicircular canal that is impacted. This causes the eye to move to correct for the head movement you’ve made. But instead of stopping like it would with your VOR as discussed above, the crystals keep moving because of gravity and inertia.

When you have canalithiasis, otoconia are stuck in the canal, the nystagmus is very brief because the rocks settle in the canal and don’t move again until you move your head again. Your canals are sending a signal to your brain that says “we are still moving” even when you’ve stopped, which causes nystagmus.

Diagnosing BPPV

BPPV is diagnosed based on nystagmus. Nystagmus is incredibly telling because it will move in a very specific direction based on the canal, and the place within the canal, that the otoconia are located. Otoconia can be located in a few different places. The first thing you need to determine is the canal in which the otoconia are residing.

It is logical to start by testing the most common canal, the posterior canal. This test is called the Dix-Hallpike (DH). This test will identify the affected side and semicircular canal and therefore guide treatment.

How To Treat BPPV

Once the correct canal is diagnosed, treatment is relatively simple. Because the otoconia respond to gravity and have likely just slipped into the wrong place, they can be rolled back out, into your otolith organ. The treatment you should receive is completely dependent on the canal that is being affected. Your physiotherapist will determine this via a series of tests and watching your nystagmus, the exact diagnosis, and the direction in which you will need to be treated. Most commonly:

• For Posterior Canal BPPV, you will need to be treated with an Epley or Semont Maneuver.
• For Horizontal Canal BPPV you will need a BBQ roll or Gufoni maneuver.

No matter the kind of BPPV you are experiencing, or how it is treated, it is most important that a professional help assist you with the maneuver.

Why Me?

Annually, about 1.6% of the population gets BPPV, with a lifetime prevalence of 2.4%, making It a very prevalent condition. Once diagnosed, it is possible that the BPPV will recur again in the next few years. Although vertigo can be scary and anxiety-provoking, once you know what it is, it is easier to self-diagnose and seek proper treatment. Fortunately, it can be treated easily through Canalith Repositioning Treatments as listed above.