The inferior laryngeal nerve (ILN), a motor and sensory branch of the tenth cranial nerve or vagus nerve, provides the motor innervation for all the laryngeal intrinsic muscles with the exception of the cricothyroid muscle and the sensory innervation of the subglottic laryngeal mucosa.
The surgical importance of the nonrecurrent inferior laryngeal nerve began to be considered from the publication by Pemberton & Beaver (1932), after its finding in a cervical surgery.
It was not until 1935 that reports began of nonrecurrent left inferior laryngeal nerves, generally associated with situs inversus (Coady et al.).
Ozan, "Detailed investigation of the relationship between the inferior laryngeal nerve including laryngeal branches and ligament of Berry," Journal of the American College of Surgeons, vol.
Meuer, "Course and branches of the recurrent laryngeal nerve, inferior thyroid artery and inferior laryngeal artery," Gegenbaurs Morphologisches Jahrbuch, vol.
The presence of a nonrecurrent inferior laryngeal
nerve (NRILN) is a significant risk factor for nerve injury during thyroid, parathyroid, and vascular surgeries involving the paratracheal area of the head and neck.
Paludetti, et al., "Voice and Swallowing Changes After Thyroidectomy in Patients Without Inferior Laryngeal
Nerve Injuries," Surgery 140, no.
There are numerous causes leading to paralysis of superior and/or inferior laryngeal
nerves, particularly of the inferior laryngeal
or recurrent nerve on its "long way" .
The safety of thyroid operations mainly depends on complete anatomic knowledge of the inferior laryngeal nerve (ILN) including all its variations.
Ozan, "Laryngeal branching pattern of the inferior laryngeal nerve, before entering the larynx," Surgical and Radiologic Anatomy, vol.
D'Alatri et al., "Voice and swallowing changes after thyroidectomy in patients without inferior laryngeal
nerve injuries," Surgery, vol.
Some reports refer to the intralaryngeal portion of the nerve as the inferior laryngeal
nerve, but we will continue to employ the term RLN.