Bilateral Vocal Fold Immobility (BVFI): refers to all etiologies of decreased vocal cord movement
Bilateral Vocal Cord Paralysis (BVCP): refers to the neurologic etiologies of BVFI (ie: those that involve the vagus nerve or its distal branches, the recurrent laryngeal nerves)
Anatomy
Nucleus Ambiguus of the Medulla Oblongata Gives Rise to Vagus Nerve
Vagus enters the jugular foramen (along with the accessory nerve and jugular vein): within jugular foramen, forms the superior ganglion (contains the cell bodies of the sensory component of the nerve, which provide sensation to the ear canal skin, via the Arnold nerve)
Vagus nerve exits the jugular foramen to form the nodose ganglion (contains the cell bodies which mediate the sensory or visceral afferents from the larynx and pharynx)
Superior laryngeal nerve arises from vagus and enters the larynx through the thyrohyoid membrane
Right recurrent laryngeal nerve arises from the vagus nerve and loops posteriorly around the subclavian artery to enter the larynx through the Killian-Jamieson area or superior to the fibers of the cricopharyngeal muscle entering the larynx at the cricothyroid space
Left recurrent laryngeal nerve arises from the vagus nerve as it crosses anterior to the aorta and lateral to the ligamentum arteriosum (remnant of the patent ductus arteriosum between the aorta and the pulmonary vein) -> courses superiorly to enter the larynx opposite the right recurrent laryngeal nerve
Epidemiology
Incidence of Etiologies of Unilateral Vocal Fold Immobility (1996-2005 data per [MEDLINE])
Surgery (46.3% of cases)
Thyroid Surgery (26% of all surgical cases)
Other Surgery (17% of all surgical cases)
Anterior Cervical Spine Surgery (15% of all surgical cases)
Carotid Endarterectomy (11% of all surgical cases)
Lung Biopsy/Resection (8% of all surgical cases)
Parathyroid Surgery (6% of all surgical cases)
Intracranial Surgery (5% of all surgical cases)
Aortic Aneurysm Surgery (5% of all surgical cases)
Heart Valve Surgery (4% of all surgical cases)
Skull Base Surgery: accounts for 2% of all surgical cases)
Thyroid and Parathyroid Surgery, Combined (1% of all surgical cases)
Idiopathic (17.6% of cases)
Malignancy (13.5% of cases)
Lung Cancer (6.6% of cases)
Metastatic Cancer (3.3% of cases)
Thyroid Cancer (2.2% of cases)
Other Cancer (0.8% of cases)
Esophageal Cancer (0.6% of cases)
Other (5.2% of cases)
Intubation (4.4% of cases)
Infection (3.6% of cases)
Central Nervous System Disease (3.0% of cases)
Trauma (2.2% of cases)
Inflammation (1.9% of cases)
Incidence of Etiologies of Bilateral Vocal Fold Immobility (1996-2005 data per [MEDLINE])
Surgery (55.6% of cases)
Thyroid Surgery (48% of all all surgical cases)
Thyroid and Parathyroid Surgery, Combined (13% of all surgical cases)
Parathyroid Surgery (29% of all surgical cases)
Carotid Endarterectomy (5% of all surgical cases)
Heart Surgery (5% of all surgical cases)
Malignancy (9.7% of cases)
Lung Cancer (4.2% of cases)
Metastatic Cancer (2.8% of cases)
Other Cancer (1.4% of cases)
Esophageal Cancer (1.4% of cases)
Thyroid Cancer (0% of cases)
Intubation (9.7% of cases)
Idiopathic (8.3% of cases)
Central Nervous System Disease/Neuropathy (6.9% of cases)
Rheumatoid Arthritis (RA) (see Rheumatoid Arthritis, [[Rheumatoid Arthritis]]): rheumatoid nodules may occur in soft tissues surrounding the cricoarytenoid joint
Mumps-Associated Laryngeal Arthritis (see Mumps Virus, [[Mumps Virus]])
Radiation Therapy Injury to Cricoarytenoid Joint (see Radiation Therapy, [[Radiation Therapy]])
External Trauma to Cricoarytenoid Joint
Internal Trauma Due to Endotracheal Tube-Related Injury to Cricoarytenoid Joint: includes posterior or anterior arytenoid displacement, posterior dislocation resulting from extubation with a partially inflated endotracheal tube cuff, arytenoid chondritis secondary to prolonged endotracheal intubation
Organophosphates (see Organophosphates, [[Organophosphates]]): nicotinic effects cause laryngospasm
Neurologic Disease/Dysfunction Involving the Vocal Folds
Alport Syndrome (see Alport Syndrome, [[Alport Syndrome]]): case report invoved a patient with chronic kidney disease, post-op from surgery with high amount of blood loss and possible impaired perfusion to recurrent laryngeal nerves (with ischemic injury) during the case
Altered Mental Status with Inability to Protect Upper Airway: typically acute
Physiology: neuropathy involving the laryngeal nerves
Mediastinal Mass/Lymphadenopathy (see Mediastinal Mass, [[Mediastinal Mass]]): in cases where large mass or nodes impact the recurrent laryngeal nerves
Paclitaxel (Taxol) (see Paclitaxel, [[Paclitaxel]])
Physiology: neuropathy involving the laryngeal nerves
Paradoxical Vocal Fold Motion (Vocal Cord Dysfunction) (see Paradoxical Vocal Fold Motion, [[Paradoxical Vocal Fold Motion]]): typically acute
Parkinson’s Disease (see Parkinson’s Disease, [[Parkinsons Disease]]): may be acute (particularly in the post-operative setting) or progressive
Postpolio Syndrome (see Poliomyelitis, [[Poliomyelitis]])
Rheumatoid Arthritis (RA) (see Rheumatoid Arthritis, [[Rheumatoid Arthritis]]): due to arteritis of vasa vasorum of recurrent laryngeal (and vagus) nerves
Physiology: arteritis of vasa vasorum of recurrent laryngeal (and vagus) nerves
Excessive Endotracheal Tube Cuff Pressure with Compression of Recurrent Laryngeal Nerve Where It Enters the Larynx
Hyperextension of Neck with Vagus Nerve Injury
Larygneal Mask Airway (LMA)-Related Injury
Recurrent Laryngeal Nerve Injury Due to Anterior Thyroid Cartilage Displacement (Relative to the Cricoid Cartilage)
Chronic
Excessive Endotracheal Tube Cuff Pressure with Compression of Recurrent Laryngeal Nerve Where It Enters the Larynx
Posterior Glottic Stenosis (PGS): due to prolonged or traumatic intubation
Vocal Cord Granuloma
Mechanical/Iatrogenic Injury to Vocal Folds
Nasogastric Tube Syndrome (see Nasogastric Tube Syndrome, [[Nasogastric Tube Syndrome]]): first reported in 1981, it is believed to be due to paresis of the posterior cricoarytenoid muscles secondary to ulceration and infection over the posterior lamina of the cricoid
Risk Group: diabetic renal transplant patients (due to prolonged gastroparesis and requirement for nasogastric tube drainage)
Proximal Esophageal Stent Placement
Radiation-Induced Injury
Radiation Injury to Vocal Cords (see Radiation Therapy, [[Radiation Therapy]])
Radiation Injury to Cricoarytenoid Joint (see Radiation Therapy, [[Radiation Therapy]]): see Cricoarytenoid Arthritis above
Chondronecrosis
Surgical Injury to Vocal Folds
Anterior Cervical Disk Surgery: typically results in unilateral injury (which may compromise the upper airway if contralateral side was previously injured)
Brainstem Surgery: may result in bilateral injury
Cardiac Surgery
Carotid Endarterectomy: typically results in unilateral injury (which may compromise the upper airway if contralateral side was previously injured)
Endolaryngeal Surgery (Using CO2 Laser): may injur posterior glottis
Esophageal Surgery: may result in bilateral injury
Thyroid Surgery (accounts for 48% of all surgical cases): may result in bilateral injury
Parathyroid Surgery: may result in bilateral injury
Tracheal Surgery: may result in bilateral injury
Diagnosis
Pulmonary Function Tests (PFT’s)
Bilateral Vocal Cord Paralysis
PEFR: decreased
FEV1: decreased
MVV: decreased
Inspiratory flow rates: decreased
FIF50/FEF50 ratio: ratio <1 suggests variable extrathoracic obstruction
Specific Findings in Bilateral Vocal Cord Paralysis
Absence of Hoarseness with Normal/Near Normal Voice: hoarseness is usually minimal with bilateral vocal cord paralysis, since both cords are in midline (weakly adducted) position and vibrate passively with phonation and expiration
Cough (with Barking Quality) (see Cough, [[Cough]])
Exertional Dyspnea (see Dyspnea, [[Dyspnea]]): occurs when airway diameter is <8 mm
May not occur until 10-20 years later
Inability to Clear Secretions
Inspiratory Stridor (see Stridor, [[Stridor]]): when airway diameter is <5 mm
During forced inspiration
May be present at rest and increase during quick or forced inspiration
Wheezing (see Obstructive Lung Disease, [[Obstructive Lung Disease]]): particularly with exertion
Treatment
Tracheostomy: may be required
References
Changing etiology of vocal fold immobility. Laryngoscope 1998;108(9):1346-1350 [MEDLINE]
The nasogastric tube syndrome. Laryngoscope. 1990 Sep;100(9):962-8 [MEDLINE]
Bilateral vocal fold paralysis caused by familial hypokalemic periodic paralysis. Otolaryngol Head Neck Surg. 1999 May;120(5):785-6 [MEDLINE]
Vocal fold immobility: a longitudinal analysis of etiology over 20 years. Laryngoscope. 2007 Oct;117(10):1864-70 [MEDLINE]
Bilateral vocal cord paralysis in a patient with chronic renal failure associated with Alport syndrome. Journal of Anesthesia June 2010, Volume 24, Issue 3, pp 472-475 [MEDLINE]
Bilateral Vocal Cord Palsy as the Sole Presentation of Acquired Syphilis. Malays J Med Sci. 2010 Apr-Jun; 17(2): 56–60 [MEDLINE]
