Laryngospasm

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Information for patients with laryngospasm

Definition

A spasm is any involuntary contraction of a muscle. If you have read much of this web site you will have seen terms like cricopharyngeal spasm or ADductor spasmodic dysphonia. The throat area has a number of muscles all of which have the potential to spasm. If laryngospasm is your condition, then the following should apply. Please be sure a physician verifies that this is your condition.

Symptoms

The symptoms are very characteristic.

  • Abrupt, sudden onset
  • May occur anytime, but often noticable when eating and talking simultaneously and something feels like it went down the wrong way
  • May be awakened in the middle of the night unable to breathe
  • I personally have had it happen while camping, when a tiny bug flew down my throat
  • Feels like you are going to die or never breathe again
  • Yet typically, it lasts less than 30 or 60 seconds
  • Very noisy and difficult “breathing in”
  • Rather easy breathing out, still able to cough
  • Faster “breathing in” makes it worse

Causes

This syndrome results from a spasm in the adductor muscles - the muscles closing or bringing the vocal folds together. From a technical standpoint, my observation is that the lateral cricoarytenoid is the main muscle activated, but possibly the thyroarytenoid as well. As soon as your voice box or the area of the windpipe below the voicebox detect the entry of water or other substance, the vocal folds spasm shut. Evolutionarily speaking, this works very well to keep water out of the lungs - if you start to drown or a bug flies down your throat while you were starting to inhale, or you inhale that glass of water, then the vocal cords very immediately and very effectively close.

That closure is a benefit to protect the airway, but it makes “breathing in” very difficult. It can happen even when only the sensation is present of something other than air entering the windpipe.

Why did I get a laryngospasm?

I believe laryngospasm is a normal response to prevent drowning or keeping fluid out of the lungs. If you truly were drowning, this is a great reflux to have functioning. That clamping shut of the vocal cords may save your lungs from a bath or long enough for you to get back to the surface. At other times though, it can be quite a nuisance.

My suspicion is that you become more susceptible to laryngospasm after an injury to the nerves of the voice box. Nerves heal by regrowing new endings, and these new nerve endings seem to be hypersensitive. Even normal things can then trigger the spasm.

It is somewhat common after one nerve has been injured and healed such as after neck surgery on the cervical spine, the carotid arteries or the thyroid glands in the neck. The nerve is usually weak for several months, then regrows.

It is an extremely common condition in patients having had nerves on both sides of their voice box injured or paralyzed. Actually paralyzed vocal cords are not really paralyzed. The nerve almost always regrows, and often crosses or mixes up connections and the vocal cord ends up with a rather permanent tension. Usually after a paralyzing injury, the vocal cords are actually closer together, spasm easily and can still close tightly.

As I have seen more patients with this condition, I have come to the conclusion that almost all cases of frequent, recurrrent laryngospasm (more than one a month), are due to an injury of one of the nerves supplying the muscles that close the vocal cords. With a close enough visual endoscopic inspection, some sign of that injury will be identified and many of the injuries to the nerve that trigger frequent laryngospasms can be treated.

Each individual laryngospasm episode is a self limiting disorder that will resolve on its own. However, the condition of being susceptible to frequent laryngospasms may go on for some time or a lifetime.

This movie shows a brief portion of a laryngospasm caught on video on a patient during surgery on her voicebox. Notice that the vocal cords come apart easily during a cough. However, she is breathing in with a great deal of effort and the vocal cords are sucked together. When you hear the noise of breathing in you will immediately recognize it if you have experienced it before.

Management program

An exam of the neck and throat is extemely important to eliminate serious problems. Your physician may consider asthma or a narrowing of the windpipe or even heart conditions as possible causes of shortness of breath. The symptoms of laryngospasm are extremely characteristic, but, one should never assume anything without a history and physical exam.

Knowing what the condition is and its short duration helps patients deal with the episodes more confidently.

The Bernoulli principle - the one you may have learned about in high school physics that keeps airplanes in the air - is the reason laryngospasm worsens with stronger attempts at breathing in. The faster the air flow through a narrow area, the lower the pressure. The voice box is the narrowest part of the windpipe so it has the lowest pressure during rapid breathing. And, in fact, laryngospasm might not be a spasm at all. It may be an inhibition or lack of ability for the opening muscles of the voice box to operate momentarily. Then, the rapid airflow through the voice box, in effect, more easily sucks the vocal folds tighter together.

With the Bernoulli principle in mind, one can see that slower breathing in will effectively get more air into the lungs than rapid breathing in. In fact, we spend most of our life breathing out, as in talking, then we take a quick breath in and spend more time talking. When one has an episode of laryngospasm, one can reverse this usual trend and take most of your time to breathe in slowly and then a quick breath out can be followed by another slow breath in. This can be repeated until the spasm stops.

Sniffing creates a reflex opening of the vocal cords. While it can be difficult to sniff aggressively during a spasm, it is often possible to breathe in through the nose, slowly and the combination of slow air movement and utilizing the nose opens the vocal cords enough to get additional air into the lungs.

An observation was made by a person with the condition that if they tilted their head backwards during an episode, it made the slow breathing-in easier. I certainly think that is plausible as I find it more difficult to oppose my own vocal cords with my neck extended backwards. By stretching the neck, it effectively lowers the voice box in the neck and that may prevent some of the clamping down by the vocal cord muscles.

Medication

I have injected botulinum toxin into the ADductor or closing muscles of the voicebox and this has diminished both the severity and frequency of episodes in some people - particularily patients with bilateral recurrent laryngeal nerve injuries. It has also helped in a few cases of unilateral recurrent laryngeal nerve paresis where there has been recovery and the paralyzed side is now hyperactive.

There may be a medication that would reduce the “tickle” sensation that triggers the episodes. Amitriptylline has sometimes been helpful in reducing throat tickles.

Surgery

  • Botulinum toxin, injected into the muscles causing the spasms, may be used to decrease or eliminate (at least for a period of a few months) frequent laryngospasms.
  • I have performed a denervation-reinnervation procedure to resupply the spasming vocal cord with a new nerve connection that does not cause the spasms. This permanently alleviates the spasms.
  • For patients with bilateral paralysis where the vocal cords are near each other all the time, I have lateralized one of the vocal cords successfully decreasing or eliminating the frequent episodes. My observation is that true bilateral paralysis is exceedingly rare and that most people with bilateral nerve injuries actually have synkinesis and the vocal cords close inappropriately when they should be opening because of "crossed" nerve connections after a nerve injury.
  • For patients who are having a great many episodes, a tracheostomy button can be placed into the windpipe from the front of the neck. This may remain capped until an episode occurs and then the patient may open it temporarily. This procedure requires some ongoing maintainence and effectivly eliminates swimming as an activity. I have never had to resort to this treatment in my patients.

Benefits

  • Understanding the disorder decreases the panic usually associated with it. Medical treatment may diminish the episodes to an acceptable level.