Jimmy Nickel works in sales and as a singer-songwriter. He comes in with complaints about singing and loss of projection. “I noted a sudden pain in my right neck while performing Naphtali in Joseph and his Technicolor Dream Coat. Afterwards it became painful to sing in my upper range so I avoided singing in falsetto. The worst part is that my voice is trashed anytime I have to project. If I use a cell phone, I am just exhausted. If I have to run a meeting, I’m exhausted. I now use a personal microphone with a speaker on my waist just to talk with my wife in the car and avoid projecting my voice. The muscles in my neck are always tight after I have to speak loudly.”
Volume and Pitch Impairment
Jimmy goes on to relate, “I first travelled to a well-known laryngologist who said I had acid reflux. I took Prilosec for several months without any benefit. Six months later I flew to another city and that laryngologist said the same thing. I took the pill again twice a day, but didn’t think it would work and it didn’t. Only massage has helped with the neck pain.”
Listening to his voice, his upper range is very strained. For a singer, he can only reach about half of a normal falsetto range. He cannot produce soft sounds above G4, fairly low even for a male. For the next six notes, he can only reach them loudly and with great effort and C5 is the absolute limit of his upper range for this trained professional singer.
On endoscopic examination, I ask him to glide up from the lowest notes in his range. As he increases his pitch, there is some rotation of his larynx, with the back of his larynx rotating toward the right side and the epiglottis tipping over toward the right side. His vocal cords do not stretch in length as he tries to go up in pitch. The left cord oscillates about its axis, but the right cord loses tension at his highest notes and oscillates lateral to its axis. We checked a CT scan of his larynx with specific attention to the cricothyroid joints and there was no visible arthritis nor visible fixation of the joints. By process of elimination, this suggests that the superior laryngeal nerve (SLN) is injured.
It is plausible that an accurate electromyogram of the CT muscles would distinguish the injury. Unfortunately, the SLN doesn’t seem to grow back as fully as the RLN. Also, I know of no good treatment to compensate for an SLN paresis. The reduced vocal range seems to be a permanent injury. I cannot say whether the injury to his nerve was a physical one or whether he had some other cause such as a viral infection of the nerve.
His vocal cords do not stretch in length as he tries to go up in pitch.
Vocal Cord Mobility Restriction
There are three types of disorders that might loosely fit under the term paralysis if we use the very broad definition of a lack of motion:
- After a tube is placed in someone’s throat (for example during anesthesia), there may be ulceration between the vocal cords with subsequent scar tissue formation contracting and fixing the vocal cords close together. All of the nerves are still sending signals to the muscles. All of the muscles are still trying to respond appropriately. However, the scar tissue holds the vocal cord joints fixed in place.
- After a surgery in the neck, the recurrent laryngeal nerve may be cut. No signal gets past the injury in the nerve. There is no motion of the vocal muscles with breathing or speaking. The muscles atrophy.
- After an injury to the RLN, the nerve re-grows, but very frequently (because the recurrent laryngeal nerve supplies muscles with opposing action) the individual fibers cross and signals to open the vocal cords go to both opening and closing muscles, so the muscles are activated, but there is no effective motion. The muscles which are stimulated simultaneously compete with each other.
In all three of these scenarios often labeled paralysis, there is a lack of motion, but the etiology is different in each one, so the treatments will need to be different.
What you learned
- The superior laryngeal nerve (SLN) controls the cricothyroid (CT) muscle, which stretches the vocal cords to raise pitch; an SLN injury eliminates upper pitch range without affecting basic cord movement.
- SLN paresis does not show up on a standard vocal cord exam — the cords open and close, but they fail to lengthen when the pitch rises, and the larynx rotates asymmetrically.
- Unlike the RLN, the SLN does not appear to recover as fully; the pitch limitation from SLN paresis is often permanent and there is no established surgical treatment.
- “Paralysis” is an imprecise term: vocal cord immobility can come from scar fixation of the joints, from a cut nerve with no signal, or from competing signals after misdirected nerve regrowth — each requiring a different approach.