NeuroTeach 43 - Cervical plexus

 Cervical plexus!

illustrated in Quain’s Anatomy

2) Formation

“anterior rami of C1-C4” - anastomosis CN XI, CN XII, and sympathetic trunk

3) Components

Cutaneous branches: GLAST Ansa cervicalis: innerv infrahyoid & geniohyoid musc Phrenic nerve: only motor nerve to innerv diaphragm Contributions to CN XI: innerv sternocleidomastoid & trapezius musc Direct muscular branches: supply prevertebral muscles of the neck

4) Superficial & deep branches

Superficial - initially pass posteriorly - cutaneous (sensory) branches - innervate the skin Deep - pass anteromedial - motor branches - innervate muscles of the neck

5) Drawing cervical plexus

1st Remember ANSA Loop 2nd Draw every letter

6) There are a total of 15 branches

1+2+3+4+5 = 15

7) Mnemonic

AH GT SO4 OATS Phrenic

8) Cutaneous branches

GLAST Greater auricular nerve (C2&C3) Lesser occipital nerve (C2) Supraclavicular nerve (C3&C4) Transverse cervical nerve (C2&C3)

9) Clinical significance

Cervical plexus block - regional anesthesia - surgery in neck region Laryngeal re-innervation - using ansa cervicalis Supraclavicular n. damage - clavicle fractures Diaphragm refers to C3-C5 dermatome - phrenic&supraclavicular n. share same roots

10) Technique

Insert the needle at the midpoint of the posterior border of the SCM to approximately half the depth of the muscle. Inject 3-4mL of local anesthetic. Also perform a subcutaneous injection of additional local anesthetic cephalad and caudad along the SCM post border

11) Summary