Lesser occipital nerve

The lesser occipital nerve, also known as the small occipital nerve, is a cutaneous branch of the cervical plexus that innervates the skin of the neck and scalp posterior and superior to the auricle.

Gross anatomy

Origin

The lesser occipital nerve arises from the ventral ramus of C2, although it often receives fibers from C3 as well.

Course

After branching from the ventral ramus of C2 the lesser occipital nerve hooks around the accessory nerve and emerges along the posterior aspect of the sternocleidomastoid muscle at the punctum nervosum (Erb’s point). The nerve then travels superiorly along the posterior border of the sternocleidomastoid muscle. At the occiput the lesser occipital nerve pierces the deep fascia and arborises. The terminal branches of the lesser occipital nerve communicates with lateral branches of the greater auricular nerve.

Branches and supply

• the lesser occipital nerve supplies the skin of the scalp, posterior third of the temporal fossa and neck posterior and superior to the auricle
• terminal branches of the small auricular nerve communicate with many other nerves including the greater auricular nerve, greater occipital nerve and the posterior auricular nerve

Relations

The lesser occipital nerve can be identified easily along the posterior border of the sternocleidomastoid muscle. It should be noted that the sensory fibers of C1 provide a branch to the meninges.

Along with the other cutaneous branches of the cervical plexus the lesser occipital nerve passes posterior to the sternocleidomastoid muscle at the punctum nervosum (Erb’s point) roughly midway between the origin and insertion of the muscle.

Related pathology

The lesser occipital nerve is implicated in occipital neuralgia along with the greater occipital nerve, both of which are derived from the C2 nerve root. It is also postulated that the lesser occipital nerve is often involved in atypical headaches and occipital origin migraines.