Bilateral Vocal Fold Paralysis
Immobility of the vocal folds refers to reduced or absent movement of the vocal folds and can be from two different causes: neurologic or mechanical (scar limiting the movement of the vocal folds). Paralysis is a term that is used when the cause of the vocal fold immobility is due to damage to its main nerve supply. In the larynx, the Recurrent Laryngeal nerve is the primary nerve supply to the majority of the laryngeal muscles. This nerve travels down from the brain and into the chest as part of the Vagus nerve before it branches off and turns upward towards the larynx. The nerve on the left side dips lower into the chest than the right side and is generally at a higher risk for injury. Paralysis of the vocal folds can be either one-sided (unilateral) or on both sides (bilateral).
Bilateral vocal fold paralysis is when both vocal folds are immobile due to a neurogenic cause. This rare circumstance can occur when surgery affects the integrity of the nerve’s function, when a tumor places pressure on the nerves, when an inflammatory process affects the nerve or in the setting of stroke or brain injury. As the vocal folds are immobile on both sides, they are unable to open, which leads to narrowing and blockage of the airway.
Symptoms
Patients with bilateral vocal fold paralysis typically present with noisy breathing or shortness of breath that will get worse with physical activity. The amount of space between the vocal folds will ultimately determine how hard it becomes for the patient to breathe. Any acute swelling, either from a virus or from surgery, can cause swelling that can make this airway even smaller and possibly even compromising the airway.
Some of these symptoms can also be mistaken for asthma, which can be lead to a delay in care.
Evaluation
An evaluation by a laryngologist is essential for any patient with bilateral vocal fold paralysis. A laryngeal exam is vital to determine the extent, if any, to which the vocal folds are mobile. When it is difficult to determine whether or not there is a paralysis, Laryngeal Electromyography (EMG) can be used to monitor the status of muscular innervation in the larynx. This involves placing a needle through the skin of the neck and into the muscles of the larynx to record the electrical activity of the muscles. Besides helping to distinguish between neurogenic and mechanical causes of vocal fold immobility, it can also help with prognosis and can sometimes indicate whether or not recovery of nerve function can be expected. It is also important to rule out tumor as a cause of the paralysis and therefore imaging of the course of the Recurrent Laryngeal nerve (neck and chest) with a CT scan is also warranted.
Treatment
Treatment can vary from observation alone to urgent surgical intervention. In acute settings, this disorder can compromise breathing and urgent intervention is warranted. This involves a tracheotomy, a surgical opening into the trachea to bypass the obstruction and establish an airway. This allows time to monitor the vocal folds in the event that function returns.
In rare cases where the paralysis has been developing over time, a patient may be relatively well compensated and not need any immediate interventions. Even in these cases, any swelling in the airway can be problematic and is not without risk.
Paradoxical Vocal Fold Motion
Paradoxical Vocal Fold Motion (PVFM) sometimes referred to as vocal cord dysfunction (VCD) impacts the ability to breath regularly. During normal function, the vocal folds open when we breathe in, and close when we hold our breath, cough, or make voice. Aside from voice use, vocal fold closure is designed to be a basic human protective mechanism to prevent things from entering into the windpipe or to get something out of the windpipe or lungs. PVFM may lead to episodes of unnecessary and counterproductive vocal fold closure that impacts a person’s ability to participate in daily activities.
Symptoms
Symptoms of PVFM include may include sudden onset of inspiratory stridor (noisy breathing) and breathing difficulty. Episodes can be triggered by environmental irritants (e.g., strong scents, dust, smoke exposure), atypical weather variants (e.g., hot or cold temperatures, dry or damp humidity), exercise and increased physical exertion, stressful environments, or voice use.
Evaluation
Evaluation for PVFM should be completed jointly with a laryngologist and voice trained SLP. Typically a comprehensive medical work-up has been performed, including previous evaluations for pulmonary disease, asthma, post-nasal drip syndrome, extrathoracic obstruction, and GERD. The physician and SLP evaluation will include: a comprehensive history intake to assess for causes and symptoms during which voice quality, breathing patterns and areas of tension are assessed; a thorough laryngoscopic and stroboscopic examination to examine patterns of vocal fold motion during breathing and vocal fold vibration.
Treatment
The first line of treatment for PVFM is typically behavioral intervention (i.e., voice therapy). Voice therapy will focus on desensitizing the throat/larynx and retraining the body’s response to triggers. This is accomplished through education on vocal hygiene, respiratory retraining techniques, laryngeal massage,and voice efficiency techniques. Medical intervention may also be recommended depending on the findings of the initial evaluation and the response to behavioral intervention.
Laryngotracheal Stenosis
Laryngotracheal stenosis(LTS) is congenital or acquired narrowing of the airway affecting the larynx and/or trachea.Subglottic stenosis (SGS) is also a term that is used to describe LTS that involves only the segment of trachea just below the vocal folds. Obstruction of the upper airway caused by LTS or SGS often results in severe morbidity and even mortality. Treatment of LTS continues to present a challenge. As a result, a wide array of surgical techniques have been employed. Despite multiple endoscopic and/or open surgical procedures, patients often experience re-stenosis as a result of the abnormal wound-healing process that initially caused the airway obstruction.
Symptoms
Initially, patients with LTS or SGS often notice difficulty breathing with exercise. In more severe cases shortness of breath at rest can even occur. One may also experience noisy, high-pitched breathing called stridor. Although breathing symptoms are most common with LTS, occasionally patients will note voice change. Additionally, they may notice that they run out of breath while speaking and have to take more frequent breathes.
Evaluation
A comprehensive head and neck examination is part of the evaluation for LTS or SGS. This typically includes a laryngoscopy (endoscopic examination of the larynx, including upper trachea) and/or tracheoscopy (endoscopic examination of entire trachea). Obtaining objective measurements of lung volumes can be helpful in LTS and SGS. Spirometry may be obtained during the office visit. This is a non-invasive exam where the patient is asked to breathe into the spirometry device. Pulmonary function tests are a complete evaluation of the respiratory system and can be done by a respiratory therapist to provide further information. A CT scan is also obtained in order to determine whether the airway narrowing is due to soft tissue scarring or cartilage collapse.
Treatment
There are medical and surgical options for treatment of LTS and SGS. There are multiple factors that influence the decision making for this process that will be fully discussed with the laryngologist at the office visit. Medical treatment may include oral systemic steroids or steroid injections into the scarred segment may be used as a treatment before or after surgery. In some cases, these injections can prevent the need for surgery. If surgical treatment is required patients may undergo minimally invasive surgery to dilate the narrowed airway. Due to the recurrent nature of LTS and SGS, patients often require repeat procedures. If there is cartilage involvement in LTS, the patient may not respond to endoscopic dilation and may require an open surgery in which resection of the stenotic segment with reattachment of the normal airway, above and below the narrowing is completed (cricotracheal or tracheal resection).
Posterior Glottic Stenosis
Immobility of the vocal folds refers to reduced or absent movement of the vocal folds and can be from two different causes: neurologic or mechanical (scar limiting the movement of the vocal folds). Posterior glottis stenosis (PGS) is a common underlying cause of immobility due to scar formation in the larynx. In this case, a scar has formed between the cricoarytenoid joints, which are the joints responsible for opening and closing the vocal folds for breathing and voice. This effectively tethers the vocal folds in a fixed position, leaving them unable to abduct (open) or adduct (close), which narrows the airway (called stenosis). This disorder is most commonly seen in patients who have been intubated for over a week, usually due to other health issues. Underlying inflammation, infection, trauma and congenital causes are also contributors to this disorder.
Symptoms
Patients with PGS present similar to patients with bilateral vocal fold paralysis in that they have noisy breathing or shortness of breath that will get worse with physical activity. The space between the vocal folds will ultimately determine how hard it becomes to breathe for a patient. Any acute swelling, either from a virus or from surgery, can make this airway even smaller or possibly even obstructing the airway. Patients can also experience voice changes. In patients with PGS, they may not have been able to be extubated (have the breathing tube removed and breath on their own). This will often result in the need for a tracheotomy.
Evaluation
An evaluation by a laryngologist is essential to evaluating PGS. A laryngeal exam is vital to determine the extent, if any, to which the vocal folds are mobile. It is also very helpful in determining the size of the airway at the level of stenosis. Other studies such as Pulmonary Function Tests and CT scans can sometimes in help in determining lung function as well as assessing for any other areas of stenosis in the airway.
Treatment
Treatment of PGS is often difficult as the underlying scar is likely to reform if it is simply cut. In some patients, injections of steroids to the area can help decrease inflammation, although this is a delicate balance as the steroids can also interfere with wound healing. Patients with PGS often require a tracheotomy to maintain the safety of their airways. Interventions are primarily aimed at opening the airway further rather than simply excising the scar (which will only re-form). A cordotomy is a procedure in which a cut is made into one of the vocal folds. This has the effect of opening the airway further, which can possibly result in increased ease of breathing and removal of the tracheotomy tube (this is called decannulation). However, the cordotomy will result in a breathy and sometimes weaker voice. Cordotomy can be completed on one or both vocal folds in an effort to decannulate the patient. It is important that a patient with PGS have a thoughtful discussion of their goals with their laryngologist as PGS is often difficult to treat and requires multiple interventions.
Subglottic Stenosis
Subglottic Stenosis (SGS) is a condition affecting the airway in the area below the vocal folds. It disrupts normal breathing by narrowing this space, making it harder for air to pass through.
In a healthy respiratory cycle, the subglottic space allows unobstructed airflow. However, in SGS, this area constricts, hindering smooth airflow. This condition can lead to breathing difficulties and impact daily activities.
Symptoms
Patients with SGS present with sudden-onset noisy breathing (stridor) and respiratory distress, triggered by factors like environmental irritants, weather changes, physical exertion, stress, or vocal use.
Evaluation
An evaluation by a laryngologist is essential to evaluating SGS. A laryngeal exam allows for partial visualization of the subglottic stenosis. A direct laryngoscopy under anesthesia may be necessary for full evaluation. CT scans can assist in determining the length and location of the stenosed area below the vocal cords. Other studies such as Pulmonary Function Tests can help determine lung function and other areas of stenosis.
Treatment
Treatment of PGS is often difficult as the underlying scar is likely to reform. Speech therapy is useful, especially in mild cases. Surgical options include dilation, possible scar excision with laser, and injection of steroids and other topical medications. It is important that a patient with SGS have a thoughtful discussion of their goals with their laryngologist as SGS is often difficult to treat and requires multiple interventions.