The Medical Consumer's Advocate

Weak voice after thyroidectomy

 

Q: I had surgery to take out a benign tumor on the right side of my thyroid. Afterwards, I lost my voice. The right side of the vocal cord was irritated by the anesthetic tube during the surgery. It has been five months without improvement on my very weak voice. Is there any hope of getting my voice back?

A: Short answer to your question: yes, but you will almost certainly need an operation.

And now for the long-winded answer. The vocal cords are a pair of muscular/ligamentous structures that are attached at one end, forming a V. The point of the V is immediately behind your Adam’s apple cartilage (the thyroid cartilage) and the V is perched above your windpipe (trachea) like an eagle sitting atop a tall tree. When you speak, the vocal cords come together: || . There is very little gap between the cords when this happens. Since there is such a small gap, we are able to generate a lot of air pressure within our lungs and trachea; we use this high pressure to cough, yell, sing, speak loudly, and so forth. If a cord is injured or paralyzed in any way, it may no longer be possible for the cords to come completely together; there may be a gap between the two cords. If you think of this gap as an "air leak," you will understand why your voice is so weak.

The nerves which innervate the muscles that move the vocal cords are the recurrent laryngeal nerves. These nerves pass behind the thyroid gland and can be stretched or cut during a thyroidectomy. Alternatively, perhaps your vocal cords were injured by the tube that the anesthesiologist placed in your trachea before your operation began (placement of this tube is known as intubation.) Cords can be torn, dislocated or paralyzed by traumatic intubation.

If I were your doctor, I would approach your case in the following manner. First, I would take a complete medical and surgical history, paying particular attention to your "weak voice" symptom. Is it constantly weak, or is it occasionally normal, occasionally weak? Has it improved at all in the last 5 months? Have you ever experienced this before? Are you certain your voice was normal prior to the operation? Was it weak immediately after waking from the anesthetic, or did it gradually become weak after the operation? Who told you that your voice is weak "because it was irritated by the anesthetic tube during surgery"-- your surgeon, or the anesthesiologist? Since the weakness has not improved, has your surgeon undertaken any investigations to learn the cause of your problem? If so, what were the results of these investigations?

Next, I would perform a complete head and neck examination. In particular, I would examine your vocal cords. While some ENTs are quite good at examining the cords using a hand-held mirror and a headlight, I must confess that for me, there is no substitute for a flexible fiberoptic scope. With a fiberoptic scope, I can take as long as I want to look at your vocal cords. This image has better magnification than what I would get with a mirror. I can videotape the exam and review it later in real time and in slow motion. I can also show the videotape to you, so that you can see the problem for yourself.

I would first examine your nasal cavities to determine which is "more open." I would then spray that nasal cavity with a combination decongestant/anesthetic. After a moment or two, I would then pass the scope through your nose. Usually, there is a tickling or an uncomfortable pressure, but pain is rare. I instruct my patients to warn me if they need to swallow, since swallowing (with a tube down your throat) may provoke a gag reflex. I can back the scope out quickly, and my patient swallows comfortably.

From this exam, I would learn whether a vocal cord is paralyzed or paretic (partially paralyzed.) I would also be able to determine if a vocal cord had been dislocated or lacerated (cut) by intubation. Weak voice can have many other causes, however, and my exam could reveal some other explanation for your problem.

By now, I would have a pretty good idea as to the cause of your weak voice. If there was any ambiguity, I would investigate further by reviewing your surgeon’s operative note, the anesthesiologist’s record, and I may also need to speak with one or both of these individuals. Nevertheless, my job as a doctor is not to assign blame, but to treat your problem. There is an excellent chance that, after a complete history and physical, I would have enough information to make a treatment recommendation.

As I mentioned at the beginning, it is very likely that your treatment will be surgical. For example, if your recurrent laryngeal nerve was severed during the operation, an operation known as a thyroplasty could restore your voice to its former strength. In this operation, the surgeon removes a rectangular "window" of cartilage from your thyroid cartilage. Through this window, the surgeon places a pre-shaped plastic block which pushes the paralyzed cord over to the midline. The non-paralyzed cord is now able to meet the paralyzed cord in the midline, forming the tight pair, || , necessary for a strong voice.

Let’s say it was unclear as to whether the nerve was stretched or cut. In that case, most ENTs would defer treatment for 6 months, since if the nerve were only stretched, it might take this long to recover function. A special study known as an EMG (electromyogram) can help your doctor determine whether the relevant muscles are permanently denervated or are, on the other hand, about to recover.

Lacerated or dislocated cords can be repaired, too, but once again the repair is surgical.

So, your job is to find an ENT who will give proper attention to your case. If you live near a medical school, you may want to call the ENT department (otolaryngology department) and ask whether they have a laryngologist on staff. A laryngologist is an ear, nose and throat surgeon who has specialized in larynx (voice box) problems. If, on the other hand, you consult an ENT from your community, question him/her very carefully about his/her experience in treating such problems.

One last piece of advice. If you are told, "there is nothing that can be done for your problem," don’t accept this answer until you have heard it from a laryngologist.

 

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