Vocal Cord Paralysis: An In-depth View
"How wonderful is the human voice! It is indeed the organ of the soul. The intellect of man is enthroned visibly on his forehead and in his eye, and the heart of man is written on his countenance, but the soul, the soul reveals itself in the voice only."
-Henry Wadsworth Longfellow
The larynx plays an important role in protecting the airway from food and saliva, while also acting as the organ of phonation. The vocal cords, a part of the larynx, produces sounds. Vocal cords are two elastic bands of muscle tissue that come together and vibrate to produce voice. When at rest, they remain in an open position to allow normal respiratory functions.
Voice is determined by three main parameters - quality, loudness, and pitch. Voice is considered disordered when one of these three parameters no longer meets the requirements of age and gender. The prevalence of voice disorders is about 7- 15 percent in general population and considerably higher in professional voice users such as singers, teachers, public speakers, etc.,. Incidence of vocal problems are more prevalent in men than women.
Voice disorders can be stressful, especially if it has a direct impact on the individual's livelihood. Many infections, chronic illness and trauma have been found to contribute to laryngeal disease. But Vocal cord paresis/palsy can have profound implications on your ability to speak, breathe and even on the protective mechanism during swallowing.
Videolaryngoscopic View of Vocal Cord Paralysis
Vocal cords produce voice by vibrations via an input from the nerve reflex mechanism. These nerve signals originate in the brain, runs through the neck and chest to supply these cords, ending in the diaphragm. Vocal cord paralysis (complete)/ paresis (partial) is the result of abnormal nerve input to the laryngeal (voice box) muscles. Paresis is a partial interruption of the nerve impulse, which results in weak or abnormal motion of these muscles. Paralysis is total interruption of nerve impulse, which results in no movement at all. Vocal cord palsy can be unilateral or bilateral.
Depending on how you use your voice, this could have a huge impact on your daily life. A mild vocal cord paresis could end a professional singer’s career or present a huge hurdle to anyone who speaks in public regularly, while it would have little to no effect on someone who does not rely on their voice for their occupation, although it may still have psychological impacts.
Universal consensus on the categorization of voice disorder is lacking. This disorder can be caused by inadvertent injury during surgery, complication from endotracheal intubation, blunt neck or chest trauma, viral infections, and tumors of the skull base, neck, and chest. Symptoms can include changes in the voice like hoarseness, extra effort on speaking, and breathy voice, airway problems including shortness of breath, noisy breathing, and ineffective cough, as well as swallowing problems like choking or coughing when swallowing. Voice disorders can be best managed in a multidisciplinary voice clinic with access to Videolaryngoscopy and Videostroboscopy for objective documentation of change in physiology. Computed tomographic (CT)/Magnetic Resonance Imaging (MRI) scans of head, neck and chest with intravenous contrast study will give clear view of any lesions along entire length of the nerve. Laryngeal electromyography can be used to measure the electric current in the voice box muscles.
Videolaryngoscopic View of Larynx
The primary treatment strategies for Vocal Cord Paralysis and Vocal Cord Paresis are voice therapy and phono surgery, an operation that re-positions and/or reshapes the vocal folds to improve voice function. Voice therapy is usually the first option pursued, with surgery becoming an option depending on the cause, severity, prognosis for recovery, and vocal needs of the patients, among other factors. Therapy includes educational information regarding phonation, vocal hygiene, recommended exercises to build strength and tone.
Sometimes, speech therapy is usually combined with surgical management. Surgical intervention (phono surgery) is usually delayed for 6-12 months to allow for spontaneous recovery. Other options include vocal cord re-positioning, injections into cords, and surgical implants to reposition the vocal cord known as thyroplasty. In cases where the cause is known, such as a skull base tumor impinging over the nerve limiting its function, removal of the tumor relieves the pressure on the nerve.
If you experience any change in quality of your voice, contact the doctor immediately for an in-depth evaluation and treatment.