Electromyography in motor disorders of the larynx.

EMG recordings have been performed from the cricothyroid and the vocal muscle in a series of patients with motor disorders of the larynx. Data obtained from 3 cases are reported. In one patient with idiopathic vocal cord paresis neurogenic lesions were found both in the vocal and in the cricothyroid muscle. In another patient subjected to thyroid surgery and in a third patient suffering from dysphonia bilateral lesions were demonstrated in the nerves to the cricothyroid muscles in both cases although there were no signs of abnormal mobility of the vocal cords at laryngoscopic examination. The results show that the EMG examination can disclose lesions in the motor nerves to the larynx which are not possible to reveal at clinical examination.