Neuro-Laryngology

Neurolaryngology is the study of voice disorders, or dysphonia, when the quality, pitch or volume of your speech differs from people of a similar age, culture and geographic location. Two common forms of dysphonia are vocal cord paralysis (which may also affect breathing and swallowing) and spasmodic dysphonia (also known as laryngeal dystonia, muscle spasms that interfere with your ability to make the controlled sounds of speech).

Dysphonia can have many causes including overuse or misuse of your voice (screaming), excessive throat clearing, substance abuse (smoking or alcohol), a physical abnormality (nodules, polyps or inflammation) or a neurological disorder (dystonia).

Vocal Cord Paralysis
Vocal cord paralysis occurs when nerve impulses to your larynx get interrupted by a neurological condition or by damage to the nerves from trauma, tumor or infection. Not only can the paralysis affect your ability to speak, it can affect your breathing because your vocal cords also protect your airway by preventing food, drink and your saliva from entering your windpipe and causing you to choke.

Unilateral vocal cord paralysis (when one vocal cord is paralyzed) is the most common form of vocal cord paralysis. About one-third are caused by tumors, injury and unknown factors. Bilateral paralysis of both vocal cords is more commonly caused by an injury and is a life-threatening condition because it interferes with your breathing.

Vocal Cord Paralysis Symptoms
Symptoms of vocal cord paralysis may include the following:

• Hoarseness
• Noisy breathing
• Loss of pitch
• Breathy vocal quality
• Shortness of breath when speaking
• Low or quiet voice
• Frequent coughing or choking when swallowing
• Frequent throat clearing
• Loss of the gag reflex

Causes include injury to the vocal cord during surgery, chest or neck injury, stroke, tumor, inflammation or a neurological disorder such as Parkinson’s disease.
Women are slightly more likely than men to experience vocal cord paralysis.

Diagnosing Vocal Cord Paralysis
Our team at Houston Methodist will ask about your symptoms and medical history, perform a general examination and evaluate your voice.
Other tests may be performed to further evaluate your voice problems:

• Examination of your vocal cords using an endoscope or a mirror to determine the position and movement of your vocal cords
• Blood tests
• Imaging scans to determine the exact nature of the nerve injury
• Laryngeal electromyogram, in which electrodes placed into the vocal cord muscles measure the electrical currents of those muscles (rarely required)

Treating Vocal Cord Paralysis
Treatment of vocal cord paralysis depends on the cause, the severity and how long you have had your symptoms. You may get better on your own, but if you do not, we may recommend voice therapy, bulk injections (collagen or other filler to bulk up the cord), surgery (structural implants, vocal cord repositioning or replacing the damaged nerve) or a combination of all of these.

Spasmodic dysphonia
Spasmodic dysphonia is a neurological disorder, like dystonia, in which the muscles of the vocal folds spasm with sudden involuntary movements that can interfere with the ability of the vocal cords to produce controlled sound.

The three types of spasmodic dysphonia include adductor spasmodic dysphonia (which slams the folds closed and causes choppy speech), abductor spasmodic dysphonia (which keeps the folds open and causes weak, quiet and breathy speech) and mixed spasmodic dysphonia (a combination of the two).

Most cases of spasmodic dysphonia are caused by neurological disorders affecting either the brain and/or peripheral nerves.

Diagnosis of Spasmodic Dysphonia
Our team at Houston Methodist— including otolaryngologists (ear, nose and throat, or ENT, specialists) and speech-language pathologists, as well as neurologists — will ask about your symptoms and medical history, perform a general examination and evaluate your voice.

Tests may be performed to further evaluate your voice problems:

• Examination of your vocal cords using an endoscope (fiber-optic laryngoscope, a small lighted tube) to determine the position and movement of your vocal cords
• Use of a strobe light in combination with the above (stroboscopy, which allows visualization of the vocal cords in slow motion)
• Speech evaluation
• Evaluation for any neurological or movement disorders that may affect your speech

Treatments for Spasmodic Dysphonia
To help restore your voice, the following treatment options may be recommended:

• Medications may be effective in approximately half of the patients
• Injections of botulinum toxin (Botox®) into the affected muscles
• Speech therapy
• One of various types of surgery

If none of these options are effective, a mechanical speech device may help you communicate more easily.