Cervical Plexus

plexus cervicalis

The cervical plexus is formed by the ventral rami of C1-C4 deep to the sternocleidomastoid in the posterior cervical triangle. Sensory branches emerge at Erb's point on the posterior SCM border (greater auricular, lesser occipital, transverse cervical, supraclavicular nerves) supplying the head, neck, and shoulder skin. Motor branches include the phrenic nerve (C3-C5), the ansa cervicalis (C1-C3 to strap muscles), and direct branches to prevertebral muscles.

Region: Neck

Clinical Relevance

Clinical Notes

Cervical plexus block at Erb's point anaesthetises the neck and shoulder for carotid endarterectomy (superficial block) and cervical node biopsy. Deep cervical plexus block at the C2-C4 transverse process level anaesthetises deeper structures for shoulder and neck surgery but carries risks of phrenic nerve block (bilateral blocks contraindicated), vertebral artery injection, and epidural/intrathecal injection. Cervical plexus nerve pain from triangle surgery or cervical pathology produces neck and occipital discomfort.

Pathology

Common Injuries & Conditions

Cervical Plexus Injury in Neck Dissection

Radical or modified radical neck dissection crossing the posterior cervical triangle sacrifices the cutaneous branches of the cervical plexus emerging at Erb's point, producing permanent numbness of the lateral neck, lower face, and shoulder skin that patients should be counselled about pre-operatively.