What causes unilateral vocal fold paralysis?
Most unilateral paralysis of the vocal folds happens for one of three reasons: nerve injury during a number of common surgeries, pressure on the nerve from a tumor growing next to it, or inflammation that stops the nerve from working, usually attributed to viral infection. Together, these three scenarios account for more than 85% of cases of paralyzed vocal folds. There are dozens of other less common causes like stroke and other neurologic disease, and side effects of certain drugs and toxins. Vocal fold paralysis may be an inadvertent result of several common surgeries, listed in the table. These include heart and lung operations, because the principal nerve of the vocal folds dips into the chest before returning to the larynx. Paralysis of the vocal fold is not necessarily a sign that the nerve has been cut. The nerve may also stop working if stretched or squeezed, and sometimes after surprisingly little handling. For this reason a vocal fold may be paralyzed after even the smoothes
