Facial Nerve Block

Facial Nerve Block

A. Indications

Blockade of the facial nerve is occasionally indi-cated to relieve spastic contraction of the facial muscles, to treat herpes zoster involving the facial nerve, and to facilitate certain surgical procedures involving the eye.

B. Anatomy

The facial nerve can be blocked where it exits the cranium through the stylomastoid foramen. A small sensory component supplies special sensation (taste) to the anterior two thirds of the tongue and general sensation to the tympanic membrane, the external auditory meatus, soft palate, and part of the pharynx.

C. Technique

The entry point is just anterior to the mastoid pro-cess, beneath the external auditory meatus, and at the midpoint of the mandibular ramus. The nerve is approximately 1–2 cm deep and is blocked with local anesthetic just below the stylomastoid process.

D. Complications

If the needle is inserted too deeply past the level of the styloid bone, the glossopharyngeal and vagal nerves may also be blocked. Careful aspiration is necessary because of the proximity of the facial nerve to the carotid artery and the internal jugular vein.