Injury of the inferior, or recurrent, laryngeal nerve is a definite hazard when subtotal thyroidectomy is performed. Knowing the anatomic variations to which this nerve may be subject near the inferior pole of the thyroid gland, the surgeon is forearmed and may avoid wounding the nerve. Occasionally, notwithstanding consummate care, homolateral paralysis of the vocal cord will be found after completion of the operation. Some unexplained injuries may be accounted for by an anomalous derivation of the inferior laryngeal nerve.
Origin of the inferior laryngeal nerve from the cervical portion of the vagus nerve is uncommon. Recently, during the performance of subtotal thyroidectomy by one of us (Pemberton) the right inferior thyroid artery was ligated in the usual manner just proximal to its entrance into the thyroid gland. At this time the inferior laryngeal nerve was seen to arise from the vagus nerve (fig. 1) and to pass directly behind