Laryngeal paralysis: distinguishing Xth nerve from recurrent nerve paralysis through videoendoscopic swallowing study (VESS).

Distinction between unilateral recurrent laryngeal nerve paralysis and Xth nerve paralysis is a rarely addressed issue in the literature. However, it may be crucial to examine the cause of the paralysis and to perform the appropriate investigation. The videoendoscopic swallowing study has been demonstrated to be a useful tool in assessing pharyngeal function. Since in unilateral Xth nerve paralysis the pharynx is impaired on the same side as the vocal fold immobility, it may be easily detected by videoendoscopic swallowing study. The rotation of the posterolateral pharyngeal wall toward the opposite side during swallowing is a sign of impaired motor pharyngeal branches. To demonstrate the usefulness of the videoendoscopic swallowing study in distinguishing unilateral Xth nerve from isolated recurrent nerve paralysis, a series of six patients were studied prospectively. Diagnosis of Xth nerve paralysis focused the investigation toward the high neck or the skull base area. Paralysis of the Xth nerve was suspected in all cases and diagnosis was achieved in five cases by the workup performed. Videoendoscopic swallowing study is a cost-effective and easily available tool which should be performed in all cases of vocal fold paralysis.