What is BPPV?

Below is a pamphlet I wrote for a physical therapy clinic. Please note, this is informational ONLY. I'm not a doctor, and I'm just providing information that you may find interesting. If you suffer from dizziness or spinning, please consult your provider. I'm not a medical professional and only glean what you can for fun and reach out to medical professionals for more information!

Do you suffer from short bursts of dizziness or a sense of the room spinning? 

There is a chance that this is BPPV and may often be treated via head positioning maneuvers.

What is BPPV?

         BPPV is an acronym for: Benign Paroxysmal Positional Vertigo. That’s a mouthful! Let’s break these words down a bit:

Benign means that it’s not malignant, doesn’t spread, and in general not systemically harmful. With that said, BPPV can lead to an increased risk for falls so it should be treated appropriately. 

Paroxysmal meaning that the symptoms are short, quick, and may be very intense in nature. 

Positional referencing that any symptoms that may occur are ONLY related to certain changes in how our head is oriented relative to the ground. 

Vertigo, which pertains to the perception that the world is moving or spinning even though it’s   actually only an awful illusion! 

         With that said, vertigo is not a diagnosis but a symptom, and there are many reasons why someone could be experiencing symptoms of vertigo. Thus, vertigo should be investigated further by your provider to potentially rule out other potential red flags. This focus of this informational pamphlet is on the basics of BPPV.

Anatomy of the Vestibular System 

         We generally think of our ear as the organ that gives us our sense of hearing. This is true, but within the penny size space of the inner ear near the cochlea houses our vestibular apparatus.  Each ear has a vestibular apparatus that does a lot of complex work and it contains:  

1.   Three semi-circular canals  

2.   Two Otolithic organs named the Saccule and the Utricle. 

3.   Three tiny ear bones (Malleus, Incus, Stapes) transmit mechanical vibrations from the ear drum to the to the inner ear. 

4.   Cochlea- looks like a snail shell and converts mechanical vibrations (sound waves) from the inner ear bones into neuro impulses so that our brain can produce the perception of hearing!

Vestibular apparatus compared to a penny 

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Anatomy of the Vestibular System

          Shown below is a right sided view of the human skull. The outer ear and some bone was removed to show the deep inner ear structures with the semicircular canals still encased in thin bone to show orientation. The 6 semi-circular canals (3 on each side of the head) work in pairs and are oriented roughly 90° off of each other. The capillary sized canals are filled with fluid and each has a sensor that detects angular movements (head rotations). When your head is still, these canals in    essence are quiet, and do not send any relative information to your brain. It is only when we move does the semi-circular canal system come alive! In the image below, arrows are pointing to the semicircular canals with a zoomed in image to the bottom left. 

Semicircular canals of right ear with bone removed to better visualize.

The three images shown below show a model that is much larger than the real organ, but it does showcase a rough approximation of the 3d orientation in the head.

Left: Back (posterior) view of canals for Right ear.       Middle: Top down view of canals, cochlea, and cranial nerve #8.      Right image: Side view for Right ear showing all three semicircular canals and cochlea. 

     Roughly in the middle of your vestibular apparatus and adjacent to your        semicircular canals are two very small structures named otolith organs. These organs have hair cells as well but are gravity dependent and are constantly telling your brain where your head is going as it relates to gravity. This includes static position as well as linear accelerations/decelerations. These hair cells are encased in a gel like material and on top sit tiny calcium carbonate crystals called otoliths (Greek for ear rocks). These crystals add some mass to the system and help contribute to the otolith organs ability to tell the brain exactly where our heads are relative to gravity at all times. Additionally, it senses 3d accelerations and decelerations at various speeds. These crystals, when they get brittle, are the key player when it comes to BPPV, which we will discuss later. If you’ve ever wanted to know how you can close your eyes as a passenger in a car and sense where you are going, you can thank your tiny otolith organs! We’ve highlighted some basic anatomy below.     

Below is a right sided Vestibular Apparatus:  

              

Left: Semicircular canals Middle: Otolithic organs Right: Cochlea

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Otoliths (highly magnified)

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Above image: Shows enlarged otolithic organ with crystal on top with movement

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           BPPV occurs when bits of these tiny crystals break off and mistakenly float into one of the semi-circular canals. Once in the canal, certain head positions/movements can cause these crystals to alter the pressure in the canal, which triggers the sensor and gives the brain a false sense of motion. It generally affects only one canal, is affected only by specific head position/movements, and may make someone briefly feel the following: dizzy, spinning sensation, unsteady, nausea, and vomiting. The key word is briefly, as constant dizziness is generally not an indicator of BPPV. If your symptoms truly come from BPPV, the main source of treatment that is ~90% effective is using gravity and various clinician driven head movements and positions to allow these crystals to migrate their way back out of the canals and back to the otolith organ for reabsorption. These treatments are canal specific and at times the treatment can cause acute symptoms.

BPPV predisposing factors 

1.      Chances are higher in older populations (up to 10%). It is rare (<3%) in people less than 40 years old.

2.      Females are about twice as likely to suffer BPPV as compared to males.

3.      The odds go up with osteopenia and osteoporosis as the crystals tend to get brittle with age and more likely to break off into the semicircular canals.

4.      The probability goes up with head trauma as this can shake crystals loose.

5.      The odds tend to go up with low Vit D serum levels as this tends to favor weaker bones and more brittle crystals.

6.      BPPV can also occur with people diagnosed with labyrinthitis, vestibular neuritis, ischemic events, and Ménière's  disease. The above can also produce symptoms of dizziness not related to BPPV, and it is possible to have overlapping issues as well!

Fun facts?

1.      Your vestibular system is highly in tune with your postural control system and a key player in allowing us to balance in our daily activities especially in low light situations. Most of this control is subconscious. 

2.      Your vestibular system is highly integrated with vision. Without the system, even simple tasks such as walking or driving a car would be very difficult.

3.      There are several automatic reflexes that occur within the vestibular system which helps us orient to gravity and/or respond to sudden perturbations to our balance. One we take for granted is our vestibular ocular reflex.

4.      Want to test your vestibular ocular reflex? 

a.   Extend your arm straight forward and stick your thumb in the air.

b.  Keep your gaze FOCUSED 100% on the thumb.

c.   Rapidly turn your head as fast as you can in any direction but DON’T lose FOCUS of your thumb.

d.  This reflex is THE fastest reflex in the human body and practically instantaneous.         

e.   For people who have lost one or both sides of this reflex, it makes focusing the eyes on moving targets           including walking and driving that much more difficult!

5. People who don’t have a functioning vestibular system can still balance but need more cues from vision and all the sensors in their skin, muscles, fascia, tendons, and ligaments (proprioception). The brain can also compensate and adapt over time (with limitations) to a vestibular system that isn’t working at 100%.