Target:

• -Arnold’s nerve origin origin
• -between posterior arches of C1 and C2, at the level of the bony facet
• -immediately next to the atlas-axis facet joint

Procedure:

• - Patient is placed prone on the CT table.
  - Axial scan from C0 - C3 for targeting and vertebral artery delineation.
  - Paramedial posterior puncture with a 25 gauge spinal needle.
  - CT fluoroscopic guidance for fast and correct needle tip placement at the level of the C2 bony facet (trigger zone).
  - 1 ml of contrast media may be injected to demonstrate correct positioning (optional).
  - Steroid injection.
  

Differential Diagnosis: if needle contact with bony facet does not trigger neuralgia, pain may be due to atlas-axis spondylosis (pseudo Arnold's neuralgia).

Danger:

• -Vertebral artery puncture : CT fluoroscopic guidance enables avoiding the artery in all cases. Always stay medial to the lateral border of the bony facet and below the artery.
• -Dural sac perforation: always stay lateral to the medial border of the facet joint.