Home › Body Atlas › Nerves › Posterior Auricular Nerve

Posterior Auricular Nerve

nervus auricularis posterior

The posterior auricular nerve is the first extracranial branch of the facial nerve (CN VII), given off just below the stylomastoid foramen. It ascends between the mastoid process and the external auditory meatus to supply the occipitalis muscle (posterior belly of occipitofrontalis), the auricularis posterior, and the intrinsic muscles on the posterior surface of the auricle. A small sensory branch supplies the skin of the ear and mastoid region.

Region: Head & Skull

Clinical Relevance

Clinical Notes

The posterior auricular nerve is tested first in facial nerve electrophysiology studies, with stimulation at the mastoid tip and recording over the auricularis posterior muscle. Its preservation as the first branch from the stylomastoid foramen is an important landmark in parotid surgery and posterior facial dissection. In Bell palsy and other facial nerve palsies, the posterior auricular nerve is typically involved, and its early return of function on electromyography is a positive prognostic sign for facial recovery.

Pathology

Common Injuries & Conditions

Posterior Auricular Nerve Injury in Mastoid Surgery

Surgical dissection at the stylomastoid foramen during mastoidectomy or parotidectomy risks injury to the posterior auricular nerve as it leaves the facial nerve, contributing to partial facial palsy affecting the occipitalis and posterior auricular muscles.

Bell Palsy Assessment

Absence of the posterior auricular nerve compound muscle action potential on electroneurography in the first week of Bell palsy indicates severe axonal loss and predicts a higher rate of incomplete recovery, guiding clinical counselling and possible early antiviral or corticosteroid treatment decisions.