Ultrasound demonstration of vocal cord movements

Examination of the vocal cords is most commonly performed by indirect laryngoscopy but this may not readily be tolerated in some patients or may not be possible immediately in certain hospitals where an ear, nose and throat (ENT) opinion is not readily available. It has been observed by the author during ultrasound examination of the thyroid that the vocal cords and their movement can be demonstrated using standard ultrasound equipment. When examining the vocal cords, it is important demonstrate abduction of the cords as well as adduction. This is because Semon's law states that a partial lesion of the recurrent laryngeal nerve affects abduction before adduction. Abduction of the cords should occur on deep inspiration.