Vocal Cord Paralysis, Unilateral

Q: What to Expect after Medialization?

Do I need to rest my voice? No. Just use it “prudently” for a few days.How long till my voice recovers? The voice will be hoarse for a few days to weeks before it “settles.” In light of this, most patients take a few days to a week off of work.How much improvement can I expect? A good result is going from 20% to 70-80%, of normal voice, but this is not guaranteed.What if I’m unhappy with my result? Sometimes we wait for further evolution; sometimes we try a few sessions of speech therapy; sometimes we do a revision surgical procedure. This is all according to the patient’s needs and other details.

Unilateral vocal cord paralysis is the neurogenic inability of one vocal cord to move. It is associated with weak voice of a degree that can vary between individuals.

What Causes Vocal Cord Paralysis?

If the recurrent laryngeal nerve gets damaged anywhere along the way from brainstem to larynx, then some or all of the vocal cord muscles might be weakened (paretic) or completely immobilized (paralyzed), thereby affecting the person’s voice or breathing.

Can the Nerve Recover on Its Own?

If the damaged nerve is still intact, then it may recover on its own, either completely or at least enough to meet the person’s vocal needs. This recovery can take up to a year because neural tissue heals much more slowly than skin or even bone.

Sometimes, though, the nerve does not recover, or not enough to meet the person’s vocal needs. There is no need to wait for a potential recovery if a tumor has invaded the nerve or if the nerve is known to be severed.

Vocal Cord Paralysis Defined by 3 Individual Muscles Denervated rather than as Recurrent Nerve Non-Function

Vocal cord paralysis is ordinarily defined as an immobile cord and thoughts go directly to recurrent nerve injury. The visual “definition” most universally used is loss of abduction (though there is also loss of medial compression). Said another way, we tend to think of the recurrent nerve being “out” but not so much of the three individual muscles that are denervated as a consequence. By contrast, paresis is defined by which one (or two) of the following muscles is/are denervated:

Posterior cricoarytenoid (PCA)
Lateral cricoarytenoid (LCA)
Thyroarytenoid (TA)

But returning to the term “paralysis,” it could be defined as denervation of all three muscles: PCA, LCA, and TA. This is shown clearly in the following set of images. Note that we typically leave out the interarytenoid (IA) muscle because it is bilaterally innervated and doesn’t often seem to figure in vocal cord paralysis.

PCA muscle not lateralizing (1 of 3)

In this open (breathing) view, the left cord (right of photo) is fully abducted. The entire photo is rotated counterclockwise, and this gives the appearance that the right cord (left of photo) is also lateralized. It is actually paramedian. This demonstrates that the PCA muscle is not lateralizing the right cord.

Right vocal process points laterally — Loss of LCA function (2 of 3)

During phonation, notice that the tip of the right vocal process at * points laterally, rather than in line with the rest of the cord. This signifies loss of LCA function.

TA denervation (3 of 3)

Under strobe light, notice the much greater amplitude (lateral excursion) of the right cord (lower part of photo), consistent with TA denervation and flaccidity.

Symptoms

One of the most common scenarios is that after investigation the cause is unknown—we call these cases idiopathic. In these cases, a virus is suspected to have played a role.

Two other causes of paresis or paralysis are tumors and trauma. Tumors in these cases could be in the thyroid, lung, esophagus, etc. Trauma is often from surgery that is performed along the path of the vagus nerve, such as for thyroid, spine, lung, or heart problems.

Other symptoms may include:

Weak, air-wasting dysphonia – The voice may be breathy, weak, double-pitched, or manifest luffing. The person may only be able to say a few words on a breath or be unable to project the voice in noisy places.
Inability to be heard in noisy locations.
A tendency of the voice to be somewhat stronger in the morning but to “fade” with use.
A tendency to cough when drinking thin liquids.

Testing That May Be Done

Laryngeal videostroboscopy

When performed at close range, this examination helps to determine which muscles are affected.

CT scan

This test helps to rule out mass lesions along the course of the nerve. A CT scan is not necessary if the cause is already known (e.g., thyroid surgery).

EMG

This is optional/controversial, and not needed in clinics where a close-range laryngeal videostroboscopy is performed.

Treatment Options

Do nothing

Just accept the symptoms while waiting, especially if recovery is thought to be possible (such as after thyroid surgery with an intact nerve, or after a presumed viral injury).
Vocal exercise with a speech pathologist

Usually helpful if the patient is taciturn. Some patients are mistakenly advised (by well-intentioned family or friends) to rest their voices. Voice rest is in fact counterproductive, except when the general fatigue caused by use of an air-wasting voice makes brief voice rest appropriate.
Voice gel (Injection Laryngoplasty) – an injected implant that is slowly absorbed and therefore temporary
This is not for definitive voice restoration, but can offer a boost while awaiting possible recovery. The aim is for modest or better benefit.
Voice gel implants are often done in-office with topical anesthesia and, occasionally, mild sedation. The gel material—hyaluronic acid—infiltrates the tissue to plump and firm so that the other vocal cord has something to push against.
Duration of benefit is typically four to twelve weeks as the gel slowly absorbs. The hope is that nerve recovery occurs during this time, but injection can be repeated if its benefit fades before it is appropriate to place a permanent implant.
Voice gel + hydroxyapatite — A semi-permanent injected implant
This option is used mostly if the patient does not want a medialization laryngoplasty (option #5 below). If placement of the filler is not ideal, a surgical adjustment might be necessary.
Medialization laryngoplasty with a silastic implant
This is performed in an outpatient operating room under local anesthesia with deep sedation (“twilight”). Surgery requires a horizontal one-inch incision on the front of the neck, and involves placement of a wedge or “shim” to permanently medialize and firm up the paralyzed vocal cord.
There are small risks of bruising and infection. Approximately one out of ten patients needs a second trip to the operating room to adjust the implant.

What to Expect after Medialization?

Do I need to rest my voice? No. Just use it “prudently” for a few days.
How long till my voice recovers? The voice will be hoarse for a few days to weeks before it “settles.” In light of this, most patients take a few days to a week off of work.
How much improvement can I expect? A good result is going from 20% to 70-80%, of normal voice, but this is not guaranteed.
What if I’m unhappy with my result? Sometimes we wait for further evolution; sometimes we try a few sessions of speech therapy; sometimes we do a revision surgical procedure. This is all according to the patient’s needs and other details.

Do I Need Surgery for Vocal Cord Paralysis?

There is unfortunately not a lot one can do to speed healing. In the photo essay Vocal Cord Paresis Accentuated by Disuse, the patient had sufficient spontaneous recovery to give her an “adequate” voice. The main thing is NOT to rest the voice as this woman did, as all that does is to atrophy any muscle that remains functional. And one can try “voice building” to see if it adds any strength.

If those things don’t work and it is 9 months or more since the onset of the paralysis, the only options are to accept the “new” voice or to proceed to medialization.

Keep in mind that one type of medialization is a simple injection (options #3 & #4), and the other is surgery through a one-inch incision (option #5).

Vocal Cord Paralysis, Before and After Medialization

vocal cord paralysis: before medialization — Vocal cord paralysis: before medialization (1 of 12)

A classic example of “spaghetti-linguine” vocal cords, here in breathing position. The “linguine” cord (left of image) is normal; the “spaghetti” cord (right of image) is paralyzed, likely since birth. On the paralyzed side, notice the deep and broad ventricle, mild bowing of the margin of the cord, and reduced width of the upper surface of the cord (“spaghetti”-like), as compared with the non-paralyzed side.

Vocal cord paralysis: 1 week after medialization (5 of 12)

One week after surgical medialization of the paralyzed cord (right of image), using a silastic implant buried deeply within the cord. Notice that the ventricle is no longer capacious, and the free margin is no longer bowed. Furthermore, in contrast with photo 1 of this series, the “spaghetti-linguine” description of these vocal cords is no longer apt.

Open phase of vocal cord vibration, under strobe light — Vocal cord paralysis: 1 week after medialization (7 of 12)

Open phase of vibration, under strobe light. The lateral or outward excursion of the paralyzed cord (right of image) is now similar to that of the non-paralyzed cord. Compare with photo 3.

Vocal cord paralysis: 5 months after medialization (9 of 12)

Five months after medialization. Compare this partially abducted position with photos 1 and 5 of this series.

Evolution of Vocal Cord Paralysis To End as PCA-only Paresis

For some voice doctors, measurement is accorded more respect than observation. Both are legitimate, of course, yet, visual (observational) understanding of paralysis and paresis remains far more useful than EMG, acoustic, or aerodynamic measurements. This case strongly illustrates that point.

This older man underwent thoracic surgery but due to complications was also intubated for much of two days. Immediately upon awakening, his voice was altered. He said it was whisper only.

At his original office visit a month later, he thought his voice had improved to “10%” and examination showed left vocal cord paralysis (TA, LCA, and PCA muscles all non-functional). Three months later, his voice was by his description to 40% and improving further week by week. By month 8 post-surgery, verified at 18 months, he felt his voice was “99%” recovered; examination showed recovery of TA and LCA, but not PCA muscle.

The final diagnosis: Left PCA-only paresis. Rather than being entirely “out,” the PCA seems only to be weak.

Left Cord Margin Bowing (TA weakness) (1 of 11)

A month after thoracic surgery that took voice from “100%” preop to “0” postop (whisper only). Breathing position (partially open) shows bowing of the left cord margin (right of photo).

LCA Paresis Also... — LCA Paresis Identified (2 of 11)

Just before vibration (phonation) begins, there is a large gap between the cords. The left TA-related bowing/atrophy remains obvious, and the tip of the vocal process (VP) is turned laterally, indicating weakness of the left LCA muscle.

Breathy voice — Voice is Breathy! (3 of 11)

Now creating an exceedingly breathy voice (see vibratory blur) with a phonation time of mere seconds due to air wasting between the cords. Two critical muscles for producing voice, TA and LCA, are not working.

The key photo showing weakness of the LCA muscle with lateral turning of the left vocal process — LCA Paresis Best View (4 of 11)

The key view is during voicing when LCA weakness is appreciated by noting lateral turning of the left vocal process (circled arrow).

At 4 months, TA bowing but is LCA working a little? — 4 Months Later, Glottis Open For Breathing (5 of 11)

Now at 4 months post-injury, this view is rotated; the left cord (right of photo is lateralized and the left (bowed) cord is actually midline. Is slight medial turning of the vocal process (VP) imaginary? That would correlate with the patient’s comment that voice is noticeably better and continuing to improve week by week.

Gap during phonation is less; slight recovery of LCA — Gap during phonation Less (6 of 11)

During phonation, the gap between the cords is less than in Photo 4, and lateral turning of the left vocal process (arrow) less exaggerated. This suggests slight recovery of the left LCA muscle.

Main deficit that remains is PCA weakness seen as lack of lateralization — PCA Weakness Is All That remains (7 of 11)

At 8 months from the injury, the patient says his voice is completely recovered. In this breathing position, one can see that the left PCA muscle which should lateralize that cord is still not working, explaining the midline position of the left cord (right of photo). But of course, the PCA muscle deficit does not affect voice, but only the size of the glottic aperture during breathing…But tone in the LCA muscle is clearly turning the vocal process medially.

Tips of vocal process turn medially on both sides now — LCA Recovered: The Vocal Process Now Turns Medially (8 of 11)

Both vocal process turn medially for phonation, suggesting recovery of the left LCA muscle, even though the right vocal process rides up on top of the left (seen not infrequentlyin older larynges).

At 18M, Left Cord Does Not Abduct Due To Continuing PCA Weakness (9 of 11)

At 18 months, and continuing to feel his voice is normal. In this breathing position, the glottic aperture is reduced because the left cord does not lateralize, consistent with ongoing weakness of the left PCA muscle. The bowing is not significant because PCA weakness coupled with normal TA and LCA create bowing while breathing, even in young people. See also the next photo.

Bowing abolished — Left PCA Can Muster Some Lateralization (10 of 11)

When the patient sniffs, his weak left PCA muscle does lateralize the cord, somewhat, abolishing the “bowing” seen in photo 9.

Healed Paresis — Full Recovery for Voicing, Despite PCA-Only Paresis (11 of 11)

At the prephonatory instant, both vocal processes come into straight-line contact (compare with photos 4 and 6. Keep in mind that PCA weakness alone does not affect voice but PCA-only paresis is seen only during breathing, as in Photo 10.

Injection Laryngoplasty with Temporary Gel