C2 and Greater Occipital Nerve: The Anatomic and Functional Implications in Spinal Surgery

CT-Guided C2 Dorsal Root Ganglion Radiofrequency Ablation for the Treatment of Cervicogenic Headache: Case Series and Clinical Outcomes

Cervicogenic headache is a secondary headache syndrome attributable to upper cervical spine pathology. Osteoarthritis of the lateral atlantoaxial joint with resultant C2 dorsal root ganglion irritation is an important and potentially treatable cause of cervicogenic headache. In this case series, we present 11 patients with cervicogenic headache who underwent C2 dorsal root ganglion thermal radiofrequency ablation. Radiologists should be familiar with this efficacious procedure and technical considerations to avoid complications.

A Prospective, Single-Blinded, Bicentric Study, and Literature Review to Assess the Need of C2-Ganglion Preservation - SAVIOUR's Criteria

Objective

Joint manipulation for craniovertebral junction instability is often hindered by the C2-ganglion (C2G). Our study aims to compare the surgical outcome among patients with or without C2G preservation and discuss the technical nuances.

Methods

We did a prospective, bicentric study and included all the operated patients with craniovertebral junction anomaly. The outcome was assessed by the Pain Numeric Rating Scale, Patient Satisfactions Score, and Stony Brook Scar Evaluation Scale. The fusion was assessed using Lenke fusion grade.

Results

One hundred seventy-one patients (88 in group A and 83 in group B) were included. The most common symptom was spastic quadriparesis (n = 165, 96.5%) with median Nurick grade 3.3. Thirteen patients had suboccipital numbness and 12 patients had paraesthesia. Mean blood loss in group A was 490 ± 96.2 mL and group B was 525 ± 45.7 mL; median operative time was 217.9 and 162.2 minutes in the groups A and B, respectively (p < 0.05). At the follow-up (median, 46.8 months), Lenke fusion grade A was achieved in 92.4% and grade B in 7.6%. A trend suggesting better functional outcomes (numbness, parestheisa, scar outcome, and postoperative ulcer formation) in group A was seen with all 6 patients, who underwent O-C2 fixation, developed pressure sore.

Conclusion

Our results support ganglion preservation, especially in the subset of patients where occipital plating is required. Although the study fails to show any statistical significance, we suggest that one should always start with an ‘intent’ of preservation as the functional outcome is better.

CT-Guided Block and Radiofrequency Ablation of the C2 Dorsal Root Ganglion for Cervicogenic Headache

The purpose of this report is to describe the technical aspects of CT-guided C2 dorsal root ganglion diagnostic block and radiofrequency ablation for refractory cervicogenic headache. CT guidance allows precise and safe positioning of a needle adjacent to the C2 dorsal root ganglion. At-risk neural and vascular structures can be avoided with CT, and it can provide a thorough understanding of upper cervical neuroanatomy.