Greater occipital nerve

The greater occipital nerve is the medial branch of the posterior ramus of the second cervical nerve (C2). It ascends obliquely between the obliquus capitis inferior and semispinalis capitis muscles, then pierces the semispinalis capitis and trapezius muscles near their attachments to the occipital bone. It may receive a communicating branch from the medial branch of the posterior ramus of the third cervical nerve (C3) at this point.

The greater occipital nerve continues to ascend on the back of the head alongside the occipital artery. It communicates with the lesser occipital nerve and supplies the skin of the scalp as far forward as the vertex of the skull.

Muscular branches: The greater occipital nerve provides motor innervation to the semispinalis capitis muscle. While less common, it may also contribute some fibers to the trapezius muscle, which is primarily innervated by the third and fourth cervical nerves (C3, C4), and the accessory nerve.

Knowledge of the greater occipital nerve's anatomy is crucial when performing nerve decompression surgeries to alleviate pain in patients suffering from migraines, cervicogenic headaches, and occipital neuralgia.