Early Internal Branch of Superior Laryngeal Nerve Bifurcation Passes Through Double Thyroid Foramen.

Internal branch of superior laryngeal nerve (ibSLN) provides sensory innervation mostly to the supraglottic part of the larynx and thus prevents aspiration during ingestion. Normally, it is distributed to the larynx after piercing the thyrohyoid membrane above the superior laryngeal artery. Multiple anatomical variations in the course of ibSLN have been reported. An early ibSLN bifurcation and course through double thyroid foramen constitutes an interesting anatomical variation that may easily lead to an injury during procedures in the thyroid gland and the larynx. Knowledge of the anatomical variability is essential in order to prevent surgical complications that could potentially impact the patient's quality of life.