Vocal Cord Paralysis: Causes, Symptoms & Treatment Options

What Is Vocal Cord Paralysis?

Vocal cord paralysis is a condition where one or both vocal cords cannot move properly due to damage to the nerves that control them. This results in voice changes, difficulty swallowing, and potentially breathing problems. The condition can be temporary or permanent depending on the underlying cause.

The vocal cords, also called vocal folds, are two bands of muscle tissue located in the larynx (voice box) at the top of the trachea (windpipe). They have three essential functions: producing sound for speech, protecting the airway during swallowing, and allowing air to pass into the lungs during breathing. When you speak, the vocal cords come together and vibrate as air passes through them. When you breathe, they move apart to allow air to flow freely.

Vocal cord paralysis occurs when the nerve signals to the vocal cord muscles are interrupted. The primary nerve involved is the recurrent laryngeal nerve, a branch of the vagus nerve that travels a long course through the neck and chest before reaching the larynx. This lengthy path makes it vulnerable to injury during various surgical procedures, particularly thyroid surgery. The condition may affect one vocal cord (unilateral paralysis) or both (bilateral paralysis), with significantly different implications for symptoms and treatment.

The paralyzed vocal cord typically remains in a fixed position, either near the midline (paramedian position) or farther to the side (lateral position). The position of the paralyzed cord determines the severity of symptoms. When the cord is fixed laterally, there is a larger gap between the cords, resulting in a weak, breathy voice but adequate breathing. When fixed in a more medial position, voice quality may be better, but bilateral medial paralysis can cause life-threatening airway obstruction.

Understanding vocal cord paralysis requires recognizing that this is not simply a voice disorder. The condition affects the protective mechanisms of the airway, potentially leading to aspiration of food or liquids into the lungs. This can result in recurrent pneumonia and serious health complications. Additionally, the condition impacts quality of life significantly, affecting not only speech but also the ability to cough effectively, exercise, and perform activities requiring increased breathing effort.

Unilateral vs. Bilateral Paralysis

Unilateral vocal cord paralysis accounts for approximately 90% of cases and affects only one vocal cord. While voice quality is impaired, most patients can breathe adequately because the functioning vocal cord compensates. The voice is typically weak, breathy, and may tire easily. Patients often experience difficulty speaking loudly, projecting their voice in noisy environments, or sustaining prolonged speech.

Bilateral vocal cord paralysis is less common but more serious. When both vocal cords are paralyzed, they may both remain near the midline, significantly narrowing the airway. This can cause stridor (noisy breathing), dyspnea (difficulty breathing), and may require emergency intervention. Paradoxically, voice quality in bilateral paralysis is often better than in unilateral cases because both cords can vibrate together, but the breathing compromise takes priority in treatment.

What Are the Symptoms of Vocal Cord Paralysis?

Common symptoms of vocal cord paralysis include a weak, breathy, or hoarse voice, difficulty swallowing with choking or coughing during meals, shortness of breath especially during physical activity, and an ineffective cough. Symptoms vary depending on whether one or both vocal cords are affected.

The symptoms of vocal cord paralysis depend on several factors, including whether one or both cords are affected, the position of the paralyzed cord, and how well the opposite cord can compensate. Symptoms typically develop suddenly if caused by surgery or trauma, or gradually if related to a tumor or neurological condition. The constellation of symptoms reflects the three main functions of the vocal cords: voice production, airway protection, and breathing.

Voice changes are usually the most noticeable symptom. Patients describe their voice as weak, breathy, hoarse, or strained. The voice may sound "rough" or "raspy," and patients often report that their voice tires easily, particularly after prolonged talking. Speaking in noisy environments becomes challenging because the patient cannot project their voice adequately. Some patients notice that their voice is worse at certain times of day or after specific activities. The pitch of the voice may also change, becoming either higher or lower than normal.

Swallowing difficulties and aspiration are significant concerns. The vocal cords normally close tightly during swallowing to protect the airway from food and liquids. With paralysis, this protective closure is incomplete, allowing material to enter the airway. Patients may cough or choke during meals, particularly with liquids or thin consistencies. Some patients develop a "wet" or "gurgly" voice quality after eating or drinking, indicating that material is pooling near or on the vocal cords. Over time, repeated aspiration can lead to pneumonia and other respiratory complications.

Voice Symptoms

• Weak, breathy voice: Air escapes through the gap between the vocal cords
• Hoarseness: The voice sounds rough or strained
• Voice fatigue: The voice tires easily with prolonged use
• Reduced volume: Difficulty speaking loudly or projecting
• Pitch changes: Voice may be higher or lower than normal
• Diplophonia: Two different pitches simultaneously (double voice)

Swallowing and Breathing Symptoms

• Choking during meals: Particularly with liquids
• Coughing while eating or drinking: Material entering the airway
• Sensation of food sticking: Feeling of incomplete swallowing
• Shortness of breath: Especially during exertion or talking
• Ineffective cough: Unable to generate adequate pressure to clear the airway
• Difficulty straining: Problems with activities requiring breath holding

What Causes Vocal Cord Paralysis?

Vocal cord paralysis is caused by damage to the nerves controlling the vocal cords. The most common causes include surgical injury (especially thyroid surgery), viral infections, tumors compressing the nerve, and neurological conditions. In 20-30% of cases, no cause is identified (idiopathic).

The recurrent laryngeal nerve, which controls vocal cord movement, has a unique and vulnerable anatomy. On the left side, the nerve descends into the chest, loops under the aortic arch, and ascends back to the larynx. On the right side, it loops under the subclavian artery higher in the chest. This long, winding course exposes the nerve to potential injury from various conditions affecting the neck, chest, and mediastinum.

Surgical injury represents the most common known cause of vocal cord paralysis, accounting for approximately 30-40% of cases. Thyroid surgery carries the highest risk because the recurrent laryngeal nerve runs directly adjacent to or through the thyroid gland. Other surgeries that can damage the nerve include carotid endarterectomy, anterior cervical spine surgery, esophageal surgery, cardiac surgery, and thoracic procedures. The risk of nerve injury during thyroid surgery ranges from 1-2% for initial procedures to 5-10% for revision surgeries. Modern surgical techniques, including intraoperative nerve monitoring, have helped reduce this risk.

Viral infections are another common cause, particularly for temporary vocal cord paralysis. Various viruses can inflame the vagus nerve or recurrent laryngeal nerve, leading to paralysis. Common culprits include herpes simplex virus, Epstein-Barr virus, influenza, and other respiratory viruses. The paralysis typically develops shortly after a viral illness and often resolves spontaneously within 6-12 months as the nerve heals.

Common Causes

Other Causes

Tumors can cause vocal cord paralysis by directly invading or compressing the recurrent laryngeal nerve anywhere along its course. Lung cancer (particularly left upper lobe tumors), thyroid cancer, esophageal cancer, and mediastinal tumors are common malignant causes. This makes new-onset vocal cord paralysis an important warning sign that requires thorough investigation to rule out malignancy, especially in patients with risk factors such as smoking history.

Neurological conditions affecting the brainstem or the vagus nerve can also cause vocal cord paralysis. Stroke affecting the nucleus ambiguus in the brainstem, multiple sclerosis, Parkinson's disease, and peripheral neuropathies are among the neurological causes. Trauma to the neck, intubation injury during anesthesia, and inflammatory conditions such as sarcoidosis can also damage the nerves controlling the vocal cords.

How Is Vocal Cord Paralysis Diagnosed?

Vocal cord paralysis is diagnosed through laryngoscopy, where a camera is passed through the nose to visualize the vocal cords. Additional tests include videostroboscopy to assess vocal cord vibration, laryngeal EMG to evaluate nerve function, and CT or MRI scans to identify underlying causes such as tumors.

Diagnosis begins with a comprehensive history and physical examination. The physician will ask about the onset and duration of symptoms, voice changes, swallowing difficulties, recent surgeries, and any history of conditions that could affect the nerves. A detailed voice assessment evaluates quality, pitch, loudness, and duration of sustained sounds. The physical exam includes examination of the head and neck, looking for masses, surgical scars, or other abnormalities.

The definitive diagnosis of vocal cord paralysis requires direct visualization of the vocal cords. Flexible laryngoscopy is the most common method, performed in the office without sedation. A thin, flexible endoscope is passed through the nose and into the throat, allowing the physician to observe the vocal cords during breathing and phonation (making sounds). The paralyzed vocal cord will appear immobile or with reduced movement, and its position (lateral or paramedian) can be assessed. This examination also allows evaluation for other conditions that might mimic or coexist with paralysis.

Videostroboscopy provides additional information about vocal cord function. This technique uses a strobe light synchronized with vocal cord vibration to create slow-motion images of cord movement. It helps assess the quality of vibration, mucosal wave characteristics, and closure patterns. This information is valuable for treatment planning and monitoring response to therapy.

Diagnostic Tests

• Flexible laryngoscopy: Office-based visualization of vocal cords through the nose
• Videostroboscopy: Detailed assessment of vocal cord vibration patterns
• Laryngeal electromyography (EMG): Measures electrical activity in laryngeal muscles; helps predict recovery potential
• CT scan of neck and chest: Identifies tumors, lymph nodes, or other masses along the nerve path
• MRI: Evaluates brainstem and skull base lesions
• Blood tests: Thyroid function, inflammatory markers, viral antibodies as indicated

When Should You See a Doctor for Voice Problems?

See a doctor if hoarseness persists for more than 3 weeks without obvious cause, if you have difficulty swallowing or breathing, if voice changes occur after neck or chest surgery, or if you experience any sudden voice loss. Early evaluation allows timely treatment and can identify serious underlying conditions.

Not all voice changes require immediate medical attention. Temporary hoarseness from a cold, voice overuse, or mild laryngitis typically resolves within a week or two. However, certain patterns of voice change warrant prompt evaluation by a healthcare provider, ideally an otolaryngologist (ear, nose, and throat specialist) with expertise in voice disorders.

The timing of voice changes relative to other events provides important diagnostic clues. Voice changes immediately following thyroid or other neck surgery should be reported promptly, as this may indicate recurrent laryngeal nerve injury. Gradual voice deterioration over weeks to months, particularly in smokers or those with other cancer risk factors, requires evaluation to rule out malignancy. Voice changes associated with difficulty swallowing, weight loss, or neck masses are particularly concerning.

For patients with known vocal cord paralysis, monitoring for complications is essential. Development of recurrent respiratory infections may suggest aspiration pneumonia. Worsening breathing difficulty, particularly with new stridor (noisy breathing), requires urgent evaluation. Changes in symptom severity or pattern should be reported, as these may indicate disease progression or development of complications.

Seek Medical Evaluation For:

• Hoarseness lasting more than 3 weeks without improvement
• Voice changes following neck or chest surgery
• Difficulty swallowing or frequent choking
• Unexplained voice changes with weight loss or neck mass
• Voice changes in patients with history of smoking
• Breathing difficulty associated with voice changes

How Is Vocal Cord Paralysis Treated?

Treatment options include voice therapy with a speech-language pathologist, injection laryngoplasty (injecting material to bulk up the paralyzed cord), medialization laryngoplasty (permanent surgical repositioning), and laryngeal reinnervation. Treatment choice depends on symptoms, expected recovery, and patient preferences.

The treatment approach for vocal cord paralysis is individualized based on several factors: the severity of symptoms, whether one or both cords are affected, the likelihood of spontaneous recovery, and the patient's overall health and personal goals. Treatment may be immediate or delayed, depending on the cause. When spontaneous recovery is expected (such as after viral illness), a period of observation with voice therapy may be appropriate. When permanent paralysis is likely (such as after nerve transection during surgery), earlier intervention may be recommended.

Voice therapy with a speech-language pathologist (SLP) is often the first-line treatment and may be sufficient for patients with mild symptoms. The therapist teaches techniques to improve vocal cord closure and voice quality without surgery. Exercises may include pushing or pulling against resistance while making sounds (to increase laryngeal effort), head-turning techniques (to help the functioning cord reach the paralyzed side), and breathing exercises. Voice therapy is also valuable in conjunction with surgical treatments to optimize outcomes.

For patients with significant symptoms who are not expected to recover spontaneously, or whose symptoms persist beyond the typical recovery window, procedural interventions become necessary. The goal of these procedures is to move the paralyzed vocal cord closer to the midline (medialization) so that the functioning cord can meet it during speech and swallowing. This reduces the gap between the cords, improving voice quality, swallowing safety, and cough effectiveness.

Voice Therapy Techniques

Speech-language pathologists employ various techniques to improve voice function in vocal cord paralysis. Pushing and pulling exercises involve making sounds while pushing against a wall or pressing the hands together, which increases effort and may help bring the paralyzed cord closer to midline. Head rotation toward the paralyzed side during speech can help improve vocal cord closure. Pitch manipulation techniques may find a pitch range where the voice functions better. Therapy also addresses compensatory behaviors that patients may develop, some of which can be harmful to long-term voice health.

Injection Laryngoplasty

Injection laryngoplasty is a minimally invasive procedure that involves injecting a bulking material into or beside the paralyzed vocal cord to push it toward the midline. The procedure can be performed in the office under local anesthesia or in the operating room, depending on the approach and patient factors. Various materials can be used, including temporary fillers (such as hyaluronic acid, which lasts 3-6 months) and longer-lasting materials (such as calcium hydroxylapatite or fat). Temporary fillers are often used when spontaneous recovery is still possible, while permanent materials may be chosen for patients with established permanent paralysis.

The results of injection laryngoplasty are often dramatic and immediate. Most patients notice improved voice strength, reduced breathiness, and better swallowing safety within days of the procedure. Success rates for voice improvement are 80-90% in appropriate candidates. The procedure can be repeated if needed, and different materials can be tried to optimize results. Complications are uncommon but may include temporary worsening of voice, infection, or suboptimal positioning requiring adjustment.

Medialization Laryngoplasty (Thyroplasty)

Medialization laryngoplasty, also known as thyroplasty type I, is a surgical procedure performed through an incision in the neck. The surgeon creates a window in the thyroid cartilage (the "Adam's apple") and places an implant that permanently pushes the paralyzed vocal cord toward the midline. The procedure is typically performed under local anesthesia with sedation, allowing the surgeon to optimize implant positioning based on real-time voice assessment during surgery.

This procedure offers permanent medialization without the need for repeated injections. Various implant materials are available, including silicone blocks, Gore-Tex, and custom-carved implants. Results are generally excellent, with most patients experiencing significant and lasting improvement in voice and swallowing. Recovery typically involves mild discomfort and voice rest for a few days, with gradual return to normal activities.

Other Surgical Options

Arytenoid adduction may be performed along with medialization laryngoplasty for patients with large posterior gaps between the vocal cords. This procedure repositions the arytenoid cartilage (which holds the back of the vocal cord) to improve posterior closure.

Laryngeal reinnervation involves connecting a functioning nerve to the paralyzed laryngeal muscle. While this does not typically restore voluntary movement, it can provide tone to the vocal cord and prevent atrophy. This procedure is most often considered in younger patients with permanent unilateral paralysis.

For bilateral vocal cord paralysis with airway compromise, the priority is ensuring adequate breathing. Procedures such as cordotomy (cutting a portion of the vocal cord), arytenoidectomy (removing part of the arytenoid cartilage), or tracheostomy (creating a breathing hole in the neck) may be necessary to open the airway, though these typically result in some voice sacrifice.

Vocal Cord Paralysis During Pregnancy and Childbirth

Pregnant women with vocal cord paralysis can receive treatment safely, though some procedures may be postponed until after delivery. The condition can affect the ability to push during vaginal delivery due to difficulty with breath holding and straining. Discuss delivery options with your healthcare team.

Pregnancy does not typically cause vocal cord paralysis, but women with pre-existing paralysis may have concerns about managing the condition during pregnancy and delivery. The good news is that most treatments are safe during pregnancy, and the condition can be managed effectively with appropriate planning.

Voice therapy with a speech-language pathologist is completely safe during pregnancy and is often the primary treatment approach. The techniques learned can help optimize voice function and swallowing safety throughout pregnancy. If injection laryngoplasty is needed, the procedure can be performed during pregnancy, though many physicians prefer to use temporary fillers and postpone permanent procedures until after delivery when possible.

The main consideration during childbirth relates to pushing during the second stage of labor. Effective pushing requires the ability to close the vocal cords, hold breath, and generate pressure. Women with vocal cord paralysis may have difficulty with this due to the incomplete glottic closure. However, most women with unilateral paralysis can still generate adequate pushing force. It is important to discuss this with your obstetrician and midwife so they can plan accordingly. In some cases, assisted delivery or cesarean section may be recommended, but many women with vocal cord paralysis deliver vaginally without significant problems.

What Is the Outlook for Vocal Cord Paralysis?

The prognosis for vocal cord paralysis varies depending on the cause. Viral and idiopathic cases often recover spontaneously within 6-12 months. Surgical injury has variable recovery rates. Even without recovery, effective treatments can significantly improve voice and quality of life for most patients.

Understanding the likely course of vocal cord paralysis helps patients and physicians make appropriate treatment decisions. The cause of paralysis is the most important factor in predicting whether spontaneous recovery will occur. Overall, approximately 30-50% of all vocal cord paralysis cases recover some or all function spontaneously, but this varies greatly by etiology.

For viral and idiopathic cases, the prognosis is generally favorable. Studies suggest that 50-70% of these patients recover vocal cord function within 6-12 months. Even among those who do not fully recover, the functioning cord often compensates over time, moving further across the midline to meet the paralyzed cord. This natural compensation can result in improved voice even without return of movement.

For surgical cases, prognosis depends on the type of nerve injury. If the nerve was stretched or bruised but not cut, recovery is possible and may occur over months. If the nerve was completely severed, spontaneous recovery is not expected. Intraoperative nerve monitoring and surgical reports can sometimes help predict recovery potential. Laryngeal EMG performed several months after injury can also provide prognostic information.

When tumors cause paralysis, the prognosis depends on the underlying malignancy. Treating the tumor may or may not restore nerve function, depending on whether the nerve has been permanently damaged. For these patients, management focuses on both treating the underlying disease and improving voice and swallowing function.

Regardless of the cause or recovery potential, it is important to know that effective treatments exist. Modern surgical and therapeutic interventions can restore functional voice and safe swallowing in the vast majority of patients with vocal cord paralysis. Quality of life outcomes are generally excellent with appropriate treatment, even in cases of permanent paralysis.

Living with Vocal Cord Paralysis

Patients with vocal cord paralysis can maintain good quality of life with appropriate management. Key strategies include voice conservation techniques, swallowing safety measures, regular follow-up with specialists, and seeking prompt treatment for respiratory infections.

Adapting to life with vocal cord paralysis involves both medical management and practical lifestyle adjustments. Voice conservation becomes important, as overusing a weakened voice can lead to fatigue and strain. Patients learn to plan demanding voice situations, take breaks during extended conversations, and use amplification devices when speaking to groups. Environmental modifications, such as reducing background noise and speaking face-to-face, can improve communication effectiveness.

Swallowing safety is a priority for patients who experience aspiration. Strategies may include taking small bites and sips, tucking the chin while swallowing, avoiding thin liquids or using thickening agents, and not talking while eating. A swallowing evaluation with a speech-language pathologist can identify specific risk factors and develop individualized safety strategies. Recognizing signs of aspiration pneumonia (fever, increased cough, shortness of breath) and seeking prompt treatment is essential.

Regular follow-up with an otolaryngologist allows monitoring of vocal cord function, assessment of treatment effectiveness, and early detection of any changes or complications. Patients who have had vocal cord paralysis should inform other healthcare providers about their condition, particularly before any procedures requiring intubation, as this information affects anesthesia planning.