Diagnostics
For the diagnosis of vocal fold paresis, a detailed interview with the patient is often sufficient. Of particular interest here are previous operations on the neck and the sometimes very pronounced hoarseness. The ENT physician can then perform a laryngoscopy to assess the movement and position of the vocal folds.
Computer tomography (CT) or magnetic resonance imaging (MRI) may be useful to rule out cancer of the larynx. A term used in the diagnosis of vocal fold paresis, which is often mentioned, is the so-called paramedian position. The term paramedic position describes the position of the vocal cords in vocal fold paresis where the closure of the vocal cords is not completely possible and one side is slightly off (para) the middle (median). This is a clear indication of damage to the laryngeal recurrent nerve. The paramedian position can be seen during laryngoscopy and is important in the differential diagnosis of vocal fold paresis, since other positions of the vocal folds such as the intermediate position (central) or lateral position (lateral) indicate other disorders.
Left vocal fold paresis
A vocal fold paresis can occur on both sides or on one side. On the left side it occurs when a surgical procedure has been performed on the left side of the neck or a tumor infiltrates the left recurrent nerve. A special feature of vocal fold paresis on the left is that the nerve on the left side has a slightly different course than on the right side. Here, the nerve extends deeper down to below the aortic arch, so that on this side, bulges or tears of the aortic arch, like an aortic aneurysm, can also cause left vocal fold paresis.Processes in the lung can also affect the nerve on the left side.
Right vocal fold paresis
On the right side, the course of the laryngeal recurrent nerve does not extend all the way into the thorax, so the probability of nerve impairment is somewhat lower than on the left side. The aorta and lungs are not in contact with the nerve on the right side. Of course, all processes, interventions and injuries to the neck can affect the nerve. If unilateral vocal fold paresis is present, the symptoms are largely independent of whether the damage is on the left or right side.
