A rare case of bifurcated lesser occipital nerve in the posterior triangle of the neck

Abstract

The origin of the lesser occipital nerve (LON) may vary, but variations in its pattern are rare. We report here a case of LON, bifurcated into superior and inferior roots in the posterior triangle of the neck. Bifurcation of the LON formed about 1.5 cm above the nerve point of the neck, near the posterior border of the sternocleidomastoid muscle. Both roots ascended obliquely upwards, and later united to form a single trunk in the upper part of the posterior triangle of the neck. It then entered the scalp where its distribution was normal. Since the cutaneous nerves of the cervical plexus are anesthetized for pain relief, as with cervicogenic headache, exceptional morphological variations of these nerves should be taken into consideration before any anesthetic procedures are performed in this region.