Vocal cord paralysis

See also Vocal cord paralysis information

With each inspiration the vocal cords should abduct (separate or spread apart) allowing air inhalation into the lungs. During vocalisation, the vocal cords adduct (come together) allowing the vibration of the vocal cord mucosa which produces speech. Complete non mobility of the vocal cords is vocal cord palsy and an incomplete movement is paresis. Either one or both vocal cords can be affected.

Bilateral vocal cord paralysis (BVCP) causes significant breathing difficulties, bronchoaspirations and is an emergency requiring an early intervention. Unilateral vocal cord paralysis (UVCP) presents with change in voice and some degree of bronchoaspiration - more for liquids than solids.

Immediately after birth, vocal cord paralysis may be secondary to compression of the brainstem, as in Arnold-Chiari malformation, meningoencephalocele or conditions with raised intracranial tension. In the newborn, the vocal cords may be paralyzed with no etiology identified (idiopathic palsy). There could be history of traumatic birth. An MRI and CT scan is done to evaluate and exclude brain, neck and mediastinal causes.

Airway management in BVCP requires non invasive ventilation (CPAP-continuous positive airway pressure) given by a mask. Tracheostomy (tube in front of the neck) is needed in 50% cases. We do not prefer laryngeal destructive procedures (arytenoidectomy, posterior cordotomy) in very small children, and these procedures are reserved in the older age groups and adults. Temporary vocal cord lateralisation can be done to buy time until definitive treatment is planned. Endoscopic posterior cricoid split with cartilage interposition has proven to give good results. Associated bronchoaspiration will need feeding by a nasogastric or gastrostomy tube.

Generally, unilateral vocal cord paralysis requires no immediate treatment. The patients have varying degrees of dyphonia and sometimes troublesome bronchoaspirations. The airway is usually adequate. With regular speech and swallow therapy, voice production improves by compensation mechanism of the opposite normal vocal cord. Later, voice quality can further be improved by surgery. That can be achieved by:

1. Vocal cord medialisation or augmentation laryngoplasty, using various implants injected endoscopically.
2. Thyroplasty, where a silicone implant is introduced into the larynx by a neck incision.