Delayed Click After Swallowing — Why?

I have this problem myself. I have been reading about this again lately and going over the reported symptoms by other people. Seeing that this thread got no replies I would like to offer my explanation of what I think is going on.

First things first, I am not a medical doctor or a trained researcher. What I will write here is my own understanding of the problem, which I have gathered by observing my own symptoms, reading about other people's symptoms, and reading a lot of texts about the ear anatomy and physiology.

Before we begin, we have to understand that many people report about symptoms of clicking ears. More often than not, the Eustachian tube is blamed for this. It's called Eustachian tube dysfunction, or ETD for short. Another often cited cause is TMD, that is Temporomandibular joint dysfunction, sometimes wrongfully abbreviated as TMJ which refers to the join itself. These may be valid causes in some people. But certainly not in as many as accounted for when people present symptoms of hearing loss and tinnitus. Yes, I am implying that people are being misdiagnosed or mislead. Being mislead by reading patient reports on the web is understandable, but being misdiagnosed by a medical doctor is unacceptable.

You can read all about ETD and TMD on other forum threads and on external websites. I will be focusing on the type of clicks that I myself have, and that a number of you on this forum appear to have.

So what is it then that you have? These are the symptoms that seem to be most common among all of those that have this.

1. Click sounds.
2. Triggered when swallowing.
3. Happens mostly during the evening and night.
4. Sometimes triggered at random without swallowing.

If you don't have ETD and you don't have TMD, then what you have here is MEMM. That is, middle ear muscle myoclonus. More precisely, it is Stapedial myoclonus. Spasms of the muscle in the middle ear in layman's terms. Not just any muscle but the smallest muscle in the human body.



What happens is that the Stapedius muscle contraction causes displacement of the Stapes head, perpendicular to the normal motion of the Stapes in response to sound. This contraction causes the head to move out of the Incudostapedial joint where the head of Stapes meets the Lenticular process of the Incus. As the muscle relaxes, the head snaps back into its original position and a click sound is generated as bone meets bone. So the click sound I believe is generated at the Incudostapedial joint.



The sound could also be generated by the Malleoincudal joint. But according to the texts I have read, the Incus and the Malleus are not displaced as a result of Stapedius muscle contraction. It's hard to imagine how it could if you look at the anatomical illustration above. The Stapes is pulled in dorsally when the muscle contracts.

 

Unlike ETD and TMD, this is a neurological disorder but it is not widely recognized as such by the medical faculty. Similar to tinnitus, it is an orphan disorder that nobody wants or knows how to deal with. That's why if you go to an ENT doctor with this symptom, he will tell you it's ETD. If you go to a dentistry specialist, he will tell you it's TMD. It all makes sense if you think about it. They are not qualified to diagnose you with something that doesn't even fall under their field of practice. So they diagnose you with what they can bill you for. If they are really smart and caring, they will not diagnose you at all. It's better not to be diagnosed at all than to be misdiagnosed and treated for something you don't have. What they should do is refer you to a neurologist. But to get to a neurologist you often need a more disabling condition and you need to have clearly visible, unilateral symptoms. To see your symptoms clearly, your GP will send you to your ENT who will diagnose you with ETD or refer you to a dentist and you are stuck in the loop between different doctors.

Even when you get to a neurologist, or even a otoneurologist, he may not be able to do much for you. He may prescribe you antispasmodic drugs which may or may not work, and you may need high doses to get an effect which may do you more harm than good. That's so typical of medicine, treating the symptoms without understanding the underlying condition. Unless your symptoms are severe, I would advise you to stay off the drugs. The only true cure perhaps for this condition is to go in there and barbarically cut the muscle. Some people have done this. They have had mixed results. Again, unless your symptoms are severe enough I would advise against it.

The exact mechanism of this disorder is unknown. Just like tinnitus, if we truly want to understand this, we need an interdisciplinary approach to its diagnosis, monitoring and treatment. Unfortunately it is not a prioritized disorder. So we will have to learn to live with it as they say. Meanwhile, what we can do is take a more active role in understanding this condition and others like it, educating other people about it, supporting good science, and lobbying for our cause.

 

What I find most interesting about this disorder is that it seems to be mostly active in evening and at night, and that it can be easily triggered during this time by swallowing. The delayed activation when swallowing is also interesting. Sometimes the click comes on 5 seconds after swallowing. Sometimes it takes 10 seconds or more. Other times it is heard at the same time as you swallow. The delayed response and the sharp click tells you more than anything that it's not ETD nor is it TMD. So that can have a clinical significance.

Here I present to you the graph of a sound recording of my own click sound, with a 15 second delay. You can find the recording attached to this post.



You need to understand that the Stapedial muscle plays a very important role in the acoustic reflex. In fact, it is so important that the acoustic reflex is sometimes referred to as the stapedius reflex. It's role is to attenuate the sound coming into the ear. When exposed to a loud noise, it is primarily the Stapedius muscle's job to protect the Cochlea by pulling the Stapes bone in dorsally, moving it away from the oval window and thereby limiting the sound level that enters the Cochlea.



The Tensor tympani muscle also plays a protective role, by stiffening the Ossicular chain and tightening the ear drum. The Tensor tympani is believed to play more of a protective role for the internal sounds, attenuating the sound of our own voice and when chewing our food. But it is mainly the Stapedius muscle that has the protective role when a very loud external noise is presented, such as that of a gun shot or a bomb blast.

Loud, sudden, impact sounds are most devastating to the ear and our hearing. Much more so than gradual exposure to loud continuous noise like that of noisy factory machines. The reason being that the protective reflex is not fast enough to act and protect the Cochlea.

Following loud noise exposure acoustic reflex threshold is lowered. Which means that both the Tensor tympani and the Stapedius muscle will contract more readily. It is as if the associated parts of the brain become more active following acoustic trauma. I would say this is in line with the hyperactivity of neurons that we use today as a model to explain tinnitus.

Just like with Cal here, my click symptoms started in one ear. That is the left ear, which is mainly my damaged ear. The damage is only mild, but it is visible on a standard audiogram. As time went by the other ear got recruited as well. So I now have the clicks in both ears, but never at the same time. Most often I hear the clicks in my left ear, and they are also louder in the left ear than the right ear. But it can vary in loudness, where a stronger contraction causes a louder click.

The neural pathways that controls these muscles and the acoustic reflex are poorly understood. Anyone who wants to understand tinnitus should study these mechanisms. They are objectively measurable and they may give us some clues about the subjective nature of tinnitus. It's needless to say that neural circuits must be mapped and well understood. Some people are for example able to voluntarily control their Tensor tympani muscles, while others are not. Why is that? How high is the prevalence for one or the other? I am one of those that can control it, I have been able to do that for as far as I can remember.

https://www.semanticscholar.org/pap...dsor/5efc78619e86a09c6566bde21553d12f3f283f3a

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2538147/