Vocal Cord Paralysis

1 What is Vocal Cord Paralysis?

Vocal cord paralysis occurs when the nerve impulses to the voice box are disrupted and the muscle become paralyzed. It can affect the ability to speak and also to breathe which can be life-threatening.

The vocal cords produce sound and prevent food, water and saliva to enter windpipe. There are numerous causes that may lead to paralysis of vocal cord muscles. Surgery is the usual treatment.

2 Symptoms

Characteristic signs and symptoms of vocal cord paralysis include:

  • breathy voice,
  • hoarseness,
  • noisy breathing,
  • loss of vocal pitch,
  • choking or coughing,
  • the need to take frequent breaths while speaking,
  • inability to speak loudly,
  • loss of gag reflex,
  • ineffective coughing,
  • frequent throat clearing.

Vocal cords are flexible muscle tissue that come together to vibrate while speaking otherwise relax to help to breathe.

In most cases, only one muscle is paralyzed but if both of them are paralyzed then there can be significant problems with breathing and swallowing.

3 Causes

The nerve impulses to the voice box are disrupted leading to their paralysis. Known causes of vocal cord paralysis include:

  • Injury to vocal cord during surgery - surgery of neck or upper chest can damage the nerves going to voice box.
  • Neck or chest injury - this can also potentially harm the nerves that serve the laryngeal muscles.
  • Stroke - stoppage of blood flow to the brain may also damage the area the send impulses to the larynx.
  • Tumors - Both cancerous and non-cancerous tumors growing around the muscles, cartilage or nerves of larynx may lead to paralysis.
  • Viral infections - Lyme diseases, Epstein-Barr disease, herpes and other such viral infections that affect the nerves or brain may cause inflammation and damage the nerves going to larynx.
  • Neurological conditions - Some underlying conditions like multiple sclerosis, Parkinson’s disease may affect the nerves and cause paralysis of larynx muscles.

4 Making a Diagnosis

The diagnosis of vocal cord paralysis will include listening to the voice, assessing voice quality and history of the problems.

If paralysis of laryngeal muscles is suspected, then the following tests may be done:

  • Laryngoscopy - having a close look at the larynx using a mirror or a thin, flexible tube with small camera.
  • Laryngeal electromyography - measuring the electrical currents in the voice box muscle and any disruption will be noted.
  • Blood test - The cause of paralysis can be viral or bacterial infections, therefore, blood test may give us results about inflammatory markers. In some cases, where the cause cannot be defined by the above mentioned tests, MRI, CT scan or X-rays can be done.

5 Treatment

Treatment depends on the severity of vocal cord paralysis. In some cases, the patient can get better without any surgical intervention therefore, the doctor may delay the surgery.

The treatment starts with bulk injections containing collagen like substance within the first 3 months of voice loss, then voice therapy is done till the time of surgery. In voice therapy, special exercises or activities are done to strengthen the vocal cords, improve breath control during speech and prevent abnormal tension.

If the patient does not recover, then the following either of the surgical options are done:

  • Bulk injections - Paralysis makes the muscle thin and weak therefore, added bulk makes then stronger. This added bulk brings the affected vocal cord closer to the non-affected one (when one vocal cord muscle is affected) and lets the person speak, swallow and cough.
  • Structural implants - An implant in the larynx to repositions the vocal cord. Procedures like thyroplasty, medialization laryngoplasty or laryngeal framework surgery are used.
  • Vocal cord repositioning - The surgeon moves the paralyzed vocal cord towards the middle of voice box and allows better vibration.
  • Replacing the damaged nerve - The damages nerve is removed and a healthy nerve from a different area of the neck is placed.
  • Tracheotomy - in this procedure, an incision is made in the front of the neck and an opening is created directly into the windpipe. This is used in extreme cases, when breathing is seriously impaired.

Some new emerging techniques like electrical stimulation of the vocal cords similar to cardiac pacemaker are being studied.

6 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with vocal cord paralysis.

Since the speaking ability is seriously impaired, it may affect the ability to communicate and become frustrating.

Voice therapy may help to know ways for effective communication.

A speech-language pathologist can teach efficient ways to use your voice without causing further damage.

7 Risks and Complications

Some potential risk factors for vocal cord paralysis include:

  • undergoing throat or chest surgery because it can damage the nerves serving the voice box,
  • having some neurological condition like Parkinson’s disease.

Sometime, the paralysis may not cause any life-threatening conditions, only hoarseness. However, it may lead to breathing problems that is complete stoppage of air flow that can even cause sudden death.

8 Related Clinical Trials