1416 - Third Occipital Nerve Block and Cooled Radiofrequency Ablation for Managing Hemicrania Continua: A Case Report

Hemicrania continua (HC) is a rare primary headache disorder characterized by persistent, unilateral pain that responds to indomethacin. This case describes a 26-year-old female with refractory HC who experienced sustained pain relief following third occipital nerve (TON) block and cooled radiofrequency ablation (RFA). The patient’s headaches began at age 8 after a mononucleosis-like illness. Over the years, she developed continuous right-sided headache with autonomic symptoms. She was diagnosed with HC, initially responding completely to indomethacin, but long-term use led to treatment failure and intolerance. Conservative and interventional treatments, including botulinum toxin injections, sphenopalatine ganglion blocks, occipital nerve stimulation, and vagal nerve stimulation, were ineffective (baseline VAS 10/10). After two diagnostic TON blocks provided pain relief, cooled RFA of the right C2–C3 medial branch was performed under fluoroscopic guidance. Pain decreased immediately to VAS 0/10, with sustained improvement (VAS 2/10) at three months and marked enhancement in quality of life.

Discussions: HC is to treat when indomethacin is contraindicated or ineffective. The TON's role in cervicogenic and headache pain makes it a viable interventional target. Thermal and cooled RFA disrupt nociceptive pathways, potentially providing greater and longer-lasting relief than nerve blocks alone. Cooled RFA allows for internal electrode cooling, which reduces peak tissue temperatures and minimizes charring, producing more consistent lesion shapes and volumes. These factors are important when targeting a small, anatomically complex sensory branch such as the TON.

Conclusions: The targeted TON block with subsequent cooled RFA provided significant, durable pain relief for a patient with refractory HC. This interventional approach may serve as an alternative for patients unresponsive to conventional treatments. Further studies are needed to validate this approach and expand its applicability to a broader patient population.