With going to vestibular therapy courses have you found that learning how to treat BPPV affecting the anterior canal is often overlooked. This is understandable to some extent given that other vestibular conditions are more prevalent. Specifically with BPPV, according to Bhattacharyya, it only affects the anterior canal up to 3% of the time. Not nearly as common as the other two canals, where much of the training focuses on.
With that being said, BPPV affecting the anterior canal is rare, but it does happen. So, if you are treating patients with dizziness it is just a matter of time until you may see this form of BPPV. When you do it will be good to have a treatment technique up your sleeve.
The theory behind BPPV is that depending on the position of the head loose otoconia fall into one of the canals. According to Bhattacharyya, 85-95% of the time the loose otoconia fall into the posterior canal, 5-15% of the time the lateral (or horizontal canal), and as indicated previously up to 3% of the time the anterior canal.
There has been some discussion, however, that BPPV affecting the lateral canal may be more prevalent than 5-15% given it having a greater chance of self resolution due to the canal orientation. Given such, care providers seeing patients acutely may see more lateral canal BPPV than care providers who typically see patients weeks after the initial onset.
Back to the anterior canal, given the vertical orientation of the canal in an upward manner, BPPV affecting the anterior canal is less common. Certain activities where the head is dependent and/or variances in canal alignment may be contributing factors to BPPV affecting the anterior canal.
According to Califano, BPPV affecting the anterior canal can mimic another rare form of BPPV affecting the posterior canal. One can read the article by Califano, but for our intents and purpose we will review anterior canal BPPV. Specifically:
The symptoms of anterior canal BPPV are very similar to BPPV affecting the other canals based on:
Tempo: Usually lasts for seconds. For this blog we will discuss canalithiasis affecting the anterior canal where the otoconia are free floating in the canal. With cupulollithiasis the otoconia are thought to be stuck to the cupula, but as cupulolithiais is less common than canalithiasis and anterior canal BPPV is rare, we will leave a rare form of a rare condition for another time.
Symptoms: Can include dizziness, spinning, light headed, unsteadiness, and/or nausea.
Circumstances: Positional changes – looking up, bending forward, rolling over in bed, and getting in/out of bed.
With anterior canal BPPV there will be unsustained (less than one minute) downbeat, torsional nystagmus with positional testing such as the Dix-Hallpike test. There may actually be a brief delay from the positional change until the nystagmus starts. It is also worth noting that the torsional component may be difficult to see and can mimic nystagmus from a central cause. To learn how to tease out the torsional component check out this 2 minute video.
The difference between BPPV affecting each different canal is the direction of the nystagmus elicited with positional testing (see chart below) and the subsequent maneuver required to get the loose otoconia out of the canal.
The below chart outlines the differences during examination. Treatment between these two conditions also differs significantly. BPPV responds well to canalith repositioning techniques (CRTs). Central vestibular conditions will not respond to CRTs and given the circumstance may require a trip to the local emergency department.
With treatment there are several options such as the Deep Head Hang (Yacovino) maneuver, the modified Epley, the Kim maneuver, and others.
This is our “Go To" choice as it is very easy to perform and it does not matter which ear is affected. It consists of 4 steps as follows:
Step 1: In sitting with neck in neutral.
Step 2: Lay back supine with at least 30o of neck extension. Hold this position until the nystagmus and dizziness stop, then an additional 30 seconds.
Step 3: While supine quickly move the chin to the chest and hold this position until the nystagmus and dizziness stop, then an additional 30 seconds.
Step 4: Sit the patient up and put the neck into a neutral alignment and hold this position until the nystagmus and dizziness stop, then an additional 30 seconds.
To see a video of how this is performed click HERE.
To see what is happening with the maneuver using a 3D fluid filled model click HERE.
Here you simply perform the modified Epley for the same side. So, if you saw down beat, right torsional nystagmus, perform the modified Epley as you would to treat the right posterior canal.
The Kim maneuver is another technique and there are others as well, but the first two we outlined should serve you well.
We hope that this provides a good resource to refer to as when treating a less common form of BPPV.
To take deeper dive into BPPV check out our A Field Guide to BPPV 6.5 hour online course.