What is Benign Paroxysmal Positional Vertigo (BPPV)?

 

 

 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 

BPPV is a condition characterized by episodes of vertigo exacerbated by changes in head position such as going to lie down in bed, rolling over in bed, or looking up or down. The episodes typically last for seconds to minutes and are better with keeping the head still in neutral position. The term “loose crystals” is used frequently to describe the calcium carbonate crystals or otoliths that have broken loose from an area of the inner ear called the utricle or saccule. These crystals are attached to the utricle and help us sense gravity in a linear fashion (i.e. moving forward or backwards).The crystals attached to the saccule help us sense gravity and linear acceleration predominantly in a vertical direction.Head trauma, a current or old inner ear infection, autoimmune/inflammatory disorders, migraine, or other inner ear disorders such as Meniere’s disease may cause the crystals to break off from the utricle or saccule. If the crystals migrate into the semicircular canals it can cause positional related vertigo or “gravity-dependent” vertigo. There are three strategically placed hair cell bundles that sit at the end of three semicircular canals (three in each ear, six total). Imagine a snow globe representing your head position and then turn it upside down. Even though your head is still, the “loose crystals” are still moving and stimulating the cupula by driving endolymphatic fluid flow, thus telling your brain that you are rotating in space. This visual-vestibular mismatch causes the vertigo sensation and may also lead to nausea and vomiting.

The anatomy of the inner ear is composed of both the cochlea (the sensory organ required for hearing) and the vestibular apparatus (which provides sensation for orientation and balance).Both of these systems, considered the labyrinth of the inner ear, are encased in the temporal bone.

 

The vestibular apparatus is the structure in the inner ear that contributes to the sensation of equilibrium, the coordination of head positioning, and the vestibulo-ocular reflexes.The system consists of the vestibule and the semicircular canals.The patient will normally have two equally functioning vestibular apparati, one for each ear, that are bathed in endolymphatic fluid.The fluid generally has the same consistency and components as cerebrospinal fluid, with the exception of slightly different potassium levels found in endolymph.This system is innervated by the eighth cranial nerve (vestibulocochlear), particularly the vestibular division of that nerve.

 

 

Anatomy/Physiology of the Inner Ear

The vestibule pertains to the two otolith organs called the utricle and the saccule.These organs respond to linear accelerations. Each of these organs has a structure called the macula, which is a single patch of sensory hair cells, on to which the otoliths attach by a “jelly” like viscous matrix.In the utricle, the macula lies in a horizontal plane, whereas in the saccule, the macula lies in a vertical plane.Thus, the utricle senses gravity predominantly in a linear horizontal direction, while the saccule distinguishes predominantly vertical linear movements.The organs do this because the otoliths (also known as otoconia “crystals”) are calcium carbonate structures that are heavier than their surroundings and deflect the kinocilium hair cells of the maculae toward the vector of linear acceleration (or gravity).Deflecting the kinocilium repolarizes the hair cells and results in sensory information transmitting to the brain stem where balance and eye movement reflexes are generated.

 

The semicircular canals refer to the structures of three looping canals found in each ear.The canals in each ear sit at approximately right orthogonal angles to each other and detect rotational head movements (angular accelerations).The canals include bilateral horizontal (lateral), anterior, and posterior semicircular canals. When the head moves, there is a corresponding movement of fluid (endolymph) within the canals that push on a structure called the cupula, found in each canal.The cupula is an accessory structure that rides on top of the crista ampullaris and deflects the kinocilium of the hair cells when endolymph passes over it.Similarly, a deflected kinocilium depolarizes hair cells in the crista and sends sensory information to the brainstem to generate compensatory balance and eye movements.The lateral canals correspond to yaw like rotation of the head.The anterior and posterior canals correspond to head movements in the pitch and roll axes, similar to those described with orientation of airplane movements.The canals work in tandem to provide a complementary signal for the brain.For example, with left horizontal canal excitation with head rotation to the left, there must also be right horizontal canal inhibition.The anterior and posterior canals are set up in a cross fashion.This means that when an anterior canal is excited, the contralateral (on the opposite side) posterior canal is inhibited. Pathology of the balance portion of the inner ear often presents in a variety of forms and can include vertigo, disequilibrium, and imbalance.

What Is Nystagmus?
 

Nystagmus is a rhythmic oscillation of the eyes, which may be physiological or pathological. Normally, the eye remains in the position of primary forward gaze, even when a person is not deliberately focusing on any visual target ahead, because of balanced input from the left and right vestibular systems, which are finely tuned to respond to any movement of the head relative to the body.

 

If a person turns his/her head to the side without making any deliberate attempt to fixate on any visual target, the eyes will remain centered in a neutral position of primary gaze as a result of vestibulo-ocular reflex (VOR; a reflex mediated via the vestibular system), which ensures that the eyes respond promptly to any movement of the head relative to the body in order to keep the eyes centered in the socket. If that person spins around in a circle (like a ballerina), theoretically the eyes should follow the head at the same speed as the person swivels around. However, if that person spins too fast, vertigo will ensue if the movement of the eyes cannot keep up with the speed of rotational movement of the head (due to the slow latency of response of the vestibulo-ocular reflex) => the vertigo is due to the disparity in eye movements relative to head movements.

 

Physiological nystagmus will occur if the conscious brain of the spinning person deliberately interferes with the smooth movement of the eyes during rotation of the body, by deliberately fixating on different visual targets during the spin. If the eyes fixate on a visual target during a rotational spin, the eyes will obviously be lagging behind the movement of the body as it continues to rotate, and it would appear to an observer that the eyes are moving smoothly in the opposite direction of the body. Ballerinas use this technique to prevent getting dizzy during rapid pirouettes. When the ballerina reaches a certain point in her rotational spin (when the eyes are displaced to the near-extreme limits of its excursion in the socket), she re-fixates her eyes on another visual target, and the voluntary saccade causes a rapid eye movement to the intended re-fixation position. In other words, the pirouetting ballerina has self-induced physiological nystagmus - a rhythmic oscillation of the eyes, with alternating fast phases and slow phases, and the fast phase occurs as a result of the conscious brain’s attempt to re-fixate a visual target.

 

A pathological nystagmus occurs when the eyes drift slowly from their intended position as a result of an abnormality of one of the slow eye movement controlling systems or the neuro-regulatory “gaze-holding” system controlling eccentric gaze(looking side to side, up or down, and obliquely).In most cases, the drift is corrected by a rapid eye movement - an automatic phenomenon of a conscious brain that brings the eye back to its intended position. Nystagmus is rarely the main clinical sign, and many patients with pathological nystagmus present with symptoms that vary depending on the underlying disease (e.g. BPPV, acute peripheral vestibulopathy, acute cerebellar syndrome, etc.).

R

L

Right Beat – These are examples of predominantly right beat nystagmus. A right beat nystagmus is defined by any eye movement pattern with a rightward-moving quick phase and a corrective slow phase back to a neutral, center position. The rightward-moving quick phase is depicted by the yellow arrow and the slow corrective phase to the left is depicted by the red arrow.

R

L

Left Beat - These are examples of predominantly left beat nystagmus. A left beat nystagmus is defined by any eye movement pattern with a leftward-moving quick phase and a corrective slow phase back to a neutral, center position. The leftward-moving quick phase is depicted by the yellow arrow and the slow corrective phase to the right is depicted by the red arrow.

R

L

Upbeat - This is an example of a predominantly upbeat nystagmus.  Upbeat nystagmus is defined as an eye movement pattern in which the slow phase is downwards and the rapid phase is upwards. The upward-moving quick phase is depicted by the yellow arrow and the slow corrective phase to the downward center position is depicted by the red arrow.

R

L

Downbeat - These are examples of predominantly downbeat nystagmus. Downbeat nystagmus is defined as an eye movement pattern in which the slow phase is upwards and the rapid phase is downwards. The downward-moving quick phase is depicted by the yellow arrow and the slow corrective phase to the upward center position is depicted by the red arrow.

R

L

Clockwise Torsion - These are examples of predominantly clockwise torsional (rotary) nystagmus. Torsional nystagmus refers to movement of the globe about its anteroposterior axis. For our examples, clockwise refers to the direction of the rotation of the eye when looking at it during a played back video. This nystagmograph example is taken from a patient with a very mild clockwise nystagmus. During each clockwise catch of torsion, the nystagmograph tracing depicts a slight left beat (green arrow) and downbeat (red arrow). For purely torsional nystagmus, video oculography is the most accurate data for diagnosis.

R

L

Counterclockwise Torsion - These are examples of predominantly counterclockwise torsional (rotary) nystagmus. Torsional nystagmus refers to movement of the globe about its anteroposterior axis. For our examples, counterclockwise refers to the direction of the rotation of the eye when looking at it during a played back video. This nystagmograph example is taken from a patient with a very mild counterclockwise nystagmus. During each counterclockwise catch of torsion, the nystagmograph tracing depicts a slight left beat (yellow arrow) and downbeat (red arrow). For purely torsional nystagmus, video oculography is the most accurate data for diagnosis.

R

L

Clockwise Torsion and Upbeat – These are examples of predominantly clockwise torsional (rotary) and upbeat nystagmus. In this type of nystagmus, the quick phase consists of both an upbeat and clockwise rotary component. For our examples, clockwise refers to the direction of the rotation of the eye when looking at it during a played back video. This nystagmographs depicts a robust clockwise torsional and upbeat nystagmus. While the direction of the torsion may not be understood just by looking at a nystagmograph tracing, it is clear from the depiction where the areas of torsion were occurring (see green arrow). The upbeat nystagmus is illustrated by a quick phase (see yellow arrow) moving upwards and a slow recovery phase (see red arrow) moving downwards.

R

L

Clockwise Torsion and Downbeat - These are examples of predominantly clockwise torsional (rotary) and downbeat nystagmus. In this type of nystagmus, the quick phase consists of both a downbeat and clockwise rotary component. For our examples, clockwise refers to the direction of the rotation of the eye when looking at it during a played back video. While the direction of the torsion may not be understood just by looking at a nystagmograph tracing, it is clear from the depiction where the areas of torsion were occurring (see green arrow). The downbeat nystagmus is illustrated by a quick phase (see yellow arrow) moving downwards and a slow recovery phase (see red arrow) moving upwards.

R

L

Counterclockwise Torsion and Upbeat - These are examples of predominantly counterclockwise torsional (rotary) and upbeat nystagmus. In this type of nystagmus, the quick phase consists of both an upbeat and counterclockwise rotary component. For our examples, counterclockwise refers to the direction of the rotation of the eye when looking at it during a played back video. While the direction of the torsion may not be understood just by looking at a nystagmograph tracing, it is clear from the depiction where the areas of torsion were occurring (see green arrow). The upbeat nystagmus is illustrated by a quick phase (see yellow arrow) moving upwards and a slow recovery phase (see red arrow) moving downwards.

R

L

Counterclockwise Torsion and Downbeat - These are examples of predominantly clockwise torsional (rotary) and downbeat nystagmus. In this type of nystagmus, the quick phase consists of both a downbeat and clockwise rotary component. For our examples, clockwise refers to the direction of the rotation of the eye when looking at it during a played back video. While the direction of the torsion may not be understood just by looking at a nystagmograph tracing, it is clear from the depiction where the areas of torsion were occurring (see green arrow). The downbeat nystagmus is illustrated by a quick phase (see yellow arrow) moving downward and a slow recovery phase (see red arrow) moving upwards.

R

L

RIGHT POSTERIOR CANALITHIASIS - This video shows a great example of a right posterior canalithiasis identified with Dix-Hallpike testing. In the Dix-Hallpike Supine Right position, an upbeat and counterclockwise torsional nystagmus is present which is indicative of otolith movement in the right posterior canal. On the nystagmograph tracing for horizontal eye movement, it is clear the eye is moving during each catch of torsion. On the nystagmograph tracing for vertical eye movement, we can see a clear quick phase in the “Up” direction and a slower recovery phase in the “Down” direction. Moving on to Neutral Sitting Position #1, this patient starts to exhibit compensatory nystagmus. Compensatory nystagmus is very common in BPPV and can be expected in most cases. As the otoliths start to move back to their original position in the posterior semicircular canal, they produce the exact opposite response that was observed in the Dix-Hallpike Supine Right position. Here the patient has a downbeat and clockwise nystagmus. The nystagmograph tracings are also opposite to what was observed in Dix-Hallpike Supine Right positioning. In both positions, the nystagmus fatigues as the patient stabilizes their head and the otoliths settle. During Dix-Hallpike Supine Left and Neutral Sitting Position #2, the patient’s eyes remain stable and no nystagmus is present. This is a clear example of a right posterior canalithiasis. Once identified, the patient can be treated with the proper Epley maneuvers.

R

L

LEFT POSTERIOR CANALITHIASIS - This video shows a great example of a left posterior canalithiasis identified with Dix-Hallpike testing. In the first two positions (Dix-Hallpike Supine Right and Neutral Sitting Position #1), the patient’s eyes remain steady and no nystagmus is present. When the patient assumes Dix-Hallpike Supine Left, a robust upbeat and clockwise nystagmus is elicited.  This is indicative of otolith movement in the left posterior semicircular canal. On the nystagmograph tracing for horizontal eye movement, it is clear the eye is moving during each catch of torsion with a slight pull to the right. On the nystagmograph tracing for vertical eye movement, we can see a clear large amplitude quick phase in the “Up” direction and the recovery phase in the “Down” direction. Moving into Neutral Sitting Position #2, the patient starts to exhibit compensatory nystagmus. Compensatory nystagmus is very common in BPPV and can be expected in most cases. The compensatory nystagmus is exhibited when otoliths moves back to their original place in the semicircular canal; producing nystagmus in the exact opposite direction that was originally observed. In this case, the compensatory nystagmus seen in Neutral Sitting Position #2 has a downbeat and counterclockwise component. This is a clear example of a left posterior canalithiasis and the patient may now be treated with the proper Epley maneuvers.

R

L

BILATERAL POSTERIOR CANALITHIASIS – This video depicts nystagmograph and video oculography findings of a patient with a mild bilateral posterior canalithiasis caused by loose otoliths in both the right and left posterior semicircular canals. In the Dix-Hallpike Supine Right position, mild counterclockwise torsional nystagmus is exhibited throughout the ten second recording. This is indicative of otolith movement in the right posterior semicircular canal. Nystagmograph tracings of eye position show both a small left and downbeat component to the direction of the counterclockwise torsion. No compensatory nystagmus is observed when the patient assumes the Neutral Sitting Position #1. As the participant moves into the Dix-Hallpike Supine Left position, a mild clockwise nystagmus is observed. This is the typical presentation of nystagmus caused by otolith movement in the left posterior semicircular canal during a Dix-Hallpike Supine Left maneuver. Close observation of the nystagmograph tracings also reveals a mild downbeating component during each quick-phase of clockwise nystagmus. When this patient sits up, she does not exhibit any compensatory nystagmus. For patients with a bilateral posterior canalithiasis, it is best to treat the side with the more robust findings first.

R

L

SUSTAINED LEFT/RIGHT BEAT NYSTAGMUS – This video depicts a predominantly sustained left beat nystagmus. A left beat nystagmus is defined by any eye movement pattern with a left-ward moving quick phase and a corrective slow phase back to a neutral, center position. In this video, the left beat nystagmus is present in all testing positions. The left beat nystagmus is visible by direct observation and also apparent in each position’s nystagmograph tracing. The quick phase of the tracing is heading to the left while the slower phase drifts right. In the Dix-Hallpike Supine Right and Dix-Hallpike Supine Left positions, a downbeat component also becomes apparent. This persistent nystagmus can be indicative of a few different pathologies. In a peripheral vestibulopathy, such as a viral neuronitis or viral labyrinthitis, a sustained nystagmus is commonly observed. Normally, the right and left vestibular organs are providing continuous input into the vestibulo-ocular reflex system. When one of the vestibular organs becomes damaged, the input balance is no longer maintained and there is a decrease of input signal from one side. This imbalance causes a sustained nystagmus which pulls the quick phase in the direction of the “good” or stronger ear. In our example, the “good” or undamaged ear is the left ear. Other pathologies that can produce a sustained nystagmus include Meniere’s disease, migraine, tumor (i.e. acoustic schwannoma), and stroke.

Our Location: 

7625 Mesa College Drive

San Diego, CA 92111

P: (858) 223-2172

F: (858) 682-2205

Right Beat