Superior semicircular canal dehiscence causes many symptoms depending on how large the hole in the canal becomes. The best-known type is vertigo caused by loud sounds. Normally the sound wave passes harmlessly by the semicircular canals and enters the cochlea, the hearing part of the ear. However, when there is a hole in the canal, the sound waves can pass into the canal and through the opening. This causes fluid movement in the canal which is sensed as spinning. There are other symptoms as well, and these can be severe.
You may notice that certain very loud tones can cause the room to rotate for a second or so. Often this rotation is just partial, about ¼ of a turn, so it looks rather like the room is tilting. It always rotates in the same direction if you have the problem in only one ear. The sound has to be quite loud, so it’s possible to deal with the problem by just avoiding loud sounds or certain tones, but it can be very annoying.
There are a lot more symptoms that are less obvious. SSCD magnifies your ability to hear sounds coming from within your body, so you might hear your heartbeat in the ear that has the leak. This can come and go. By paying close attention, you may also hear your eyes move. Close your eyes and move them from side to side. When you move them firmly and quickly toward the leaky ear, you may hear a very high-pitched, soft Zhing! sound. This is an almost certain sign of SSCD.
Hearing can also be affected. The ear with the leak may have a mild or moderate, perhaps gradually worsening hearing loss and some constant ringing linked to that. It can feel a bit stuffy, like a seashell held to the ear. Sometimes this is mistaken for Meniere’s disease, but real Meniere’s disease causes attacks with prolonged constant vertigo lasting for hours, which is different from SSCD. It’s likely that SSCD can cause Meniere’s disease to develop, however.
In rare severe cases, your pulse can be turned into vertigo. The brain constantly pulses with each heartbeat, and also shows pressure changes when breathing. These can be transmitted through the hole in the canal to the ear. If the leak is large, you can feel this as vertigo. Each pulse causes the room to rotate ¼ turn, forward and to the left if the left ear is the source, forward and to the right if the right ear is the problem. It can feel as if you are briefly flipping upside down and to the side. Holding your breath can stop the vertigo, but it resumes when the next breath is taken. Coughing, sneezing and bearing down or straining can also cause similar brief spinning feelings. This kind of vertigo can be severely disabling.
In our next post, we’ll talk about how the leak can be fixed.