I was diagnosed with eustachian tube disorder (ETD) last year. I was awakened twice lately by a loud "slapping on a table" pulsating sound in one ear. I also have sharp ear pain occasionally. Does ETD cause any of these symptoms? Thanks!

R.H.

Eustachian tube dysfunction (ETD) usually causes a feeling of ear pressure. This is the same sensation you may have while driving into the mountains or descending in an airplane -- it's the "I need to pop my ears!" feeling. As I've written in an earlier column on ETD, you feel this way because there really is a pressure difference between the outside world and the middle ear space (the space behind the eardrum).

The eustachian tube (ET) is a muscular tube that connects the middle ear to the throat. Most of the time, the ET is collapsed; when it opens (when you "pop your ears") air can flow through the tube into the middle ear space. This causes the air pressure in the middle ear space to become equal to the air pressure in the room. When the ET fails to open, however, a pressure difference can build, and a varied array of symptoms may arise. Ear pain, hearing loss, ringing (tinnitus) and dizziness (unsteadiness, or even true vertigo) are not uncommon. Since some folks do not localize pain well, ETD can sometimes be reported as a fairly nonspecific headache or facial pain.

But can ETD cause that slapping noise? Well, maybe, but the slapping noise is a much different problem. The slapping noise is most likely myoclonus, which means "muscle spasm." If a muscle in your leg twitches, you feel it; if a muscle in (or near) your ear twitches, you hear it (and may feel it, too). Since the causes of myoclonus are a bit mysterious, I would have to say, "Sure, ETD might be causing your myoclonus."

You may recall that sound is really vibration, and this energy passes from the outside world to the inner ear via the following pathway: ear canal, eardrum, middle ear bones (malleus, incus, then stapes), cochlea (the auditory portion of the inner ear). There are two tiny muscles in the inner ear that attach to middle ear bones. The stapedius muscle is attached to the stapes, and the tensor tympani muscle is attached to the malleus. If either of these muscles develops a twitch, you are sure to hear it. The stronger the twitch, the louder the "rap-rap-rap." That's why folks with this problem report anything from "the sound of butterfly wings gently beating" to your report of "slapping on a table."

One can also develop myoclonus of the eustachian tube muscles; this is known as palatal myoclonus, due to the fact that these muscles arise from the palate (roof of the mouth). In addition to a repetitive sound, patients with palatal myoclonus may also feel the twitch in their mouth or throat.

Many patients with this problem require only reassurance. Once they understand the problem, they can live with it. If the slapping noise happens often enough to REALLY drive you nuts, then there are medications (antispasticity drugs, tranquilizers) that could prove helpful. If these medications do not work, an operation can be performed (to sever the offending muscle, if it is the stapedius or tensor tympani). For palatal myoclonus, injection with the muscle-paralyzing drug Botox can be helpful. Needless to say, you must be fully evaluated by a knowledgeable doctor first and treated appropriately under a doctor's supervision.