Third occipital nerve
Nervus occipitalis tertius
- Latin synonym: Ramus posterior medialis nervi cervicalis tertii
- Synonym: Medial branch of posterior ramus of third cervical nerve
Definition
The third occipital nerve is the medial branch of the posterior ramus of the C3 spinal nerve. It provides sensory innervation to the skin of the lower occiput and upper cervical region, and motor innervation to the semispinalis capitis muscle.
Emerging between the C2 and C3 vertebrae, the third occipital nerve ascends and pierces the semispinalis capitis and splenius capitis muscles. It then continues superiorly, piercing the trapezius muscle before becoming subcutaneous. Potential entrapment points along its course include the C2-C3 intervertebral space and the points where it pierces the semispinalis capitis, splenius capitis, and trapezius muscles.
The third occipital nerve is closely related to the greater occipital nerve, which is the medial branch of the posterior ramus of the C2 spinal nerve. Both nerves contribute to the sensory innervation of the scalp and can be involved in occipital neuralgia. Understanding their anatomical pathways is essential for the diagnosis and management of related pain conditions, including nerve blocks and surgical interventions.
References
Drake, R.L., Vogl, A.W., and Mitchell, A.W.M. (2010). ‘Chapter 8: Head and Neck’, in Gray’s anatomy for students. (2nd ed.) Churchill Livingstone Elsevier, Philadelphia PA 19103, pp.875.
Saglam L, Coskun O, Kale A, Gayretli O. A Comprehensive Study of the Potential Compression Points of the Third Occipital Nerve and Its Possible Clinical Interests. Plast Reconstr Surg. 2024 Dec 1;154(6):1220e-1228e.
Tubbs RS, Mortazavi MM, Loukas M, D'Antoni AV, Shoja MM, Chern JJ, Cohen-Gadol AA. Anatomical study of the third occipital nerve and its potential role in occipital headache/neck pain following midline dissections of the craniocervical junction. J Neurosurg Spine. 2011 Jul;15(1):71-5.
