Sometimes maneuvers for H-BPPV don’t seem to work, and this is especially true for the apogeotropic type, when the eyes seem to beat toward the ceiling when lying on your side. It’s very rare to have this happen. Most of the time, lying flat on your back until the dizziness stops and then doing one of the maneuvers for H-BPPV is enough. About 1 in 100 people, however, will have particles that get entrapped in the canal. Because they are stuck, they can’t be removed easily with a simple maneuver.
There is a mystery here—where exactly are they stuck, and why? In the past, this problem was always blamed on cupulolithiasis, particles that enter the canal and become attached to the cupula. Otoconia are sticky, so it’s not unreasonable to think they could be stuck on the sensor, but is the cupula the most likely place to stick?
When the photo in our last post was taken, Dr. Kalmanson was able to agitate the sample and get the otoconia to shift around on the cupula, so they didn’t seem to be permanently attached. They did like to stick to everything—the instruments, the membranes, and especially to the cut edges of the membranes. We’ve known for many years that they can stick in the canals, because when we first do maneuvers, sometimes they fail to move and the person we’re treating doesn’t get dizzy. Putting a vibrator on the head helps get them to unstick and start to move, so we’ll do that when our patient does not respond to maneuvers.
So the first step when maneuvers don’t resolve the dizziness is to use a vibrator. Sometimes we’ll have to do several maneuvers in a row, vibrating all along to get all the particles out. If that isn’t enough, we will tap hard behind the ear with our fingers. Very rarely, even this does not work. The otoconia seem to be completely stuck. Were these cases cupulolithiasis, or was something else going on? We’ll discuss a new answer in the next post.