Refractory occipital neuralgia: preoperative assessment with CT-guided nerve block prior to dorsal cervical rhizotomy.

BACKGROUND AND PURPOSE Occipital neuralgia syndrome can cause severe refractory headaches. In a small percentage of people, these headaches can be devastating and debilitating, with the potential for complete relief following surgical rhizotomy. We describe CT fluoroscopy-guided percutaneous C2-C3 nerve block for the confirmation of diagnosis of occipital neuralgia and for demonstrating to patients the sensory effects of intradural cervical dorsal rhizotomy before the definitive surgical procedure. METHODS Seventeen patients with occipital neuralgia underwent 32 CT fluoroscopy-guided C2 or C2 and C3 nerve root blocks. Of the 17 patients, nine had occipital neuralgia following prior neck or skull base surgeries. On the basis of the positive results of the nerve blocks in terms of temporary pain relief, all 17 patients underwent unilateral (n = 16) or bilateral (n = 1) intradural C1 (n = 9), C2 (n = 17), C3 (n = 17), or C4 (n = 7) dorsal rhizotomies. All patients were followed up for a mean of 20 months (range, 5-37 months) for assessment of pain relief. Sixteen patients were assessed for degree of satisfaction with and functional state after surgery. RESULTS All patients had temporary relief of symptoms after percutaneous CT-guided block (positive result) and felt that occipital numbness was an acceptable alternative to pain. Immediately after surgery, all patients had complete relief from pain. At follow-up, 11 patients (64.7%) had complete relief of symptoms, two (11.8%) had partial relief, and four (23.5%) had no relief. Seven of eight (87.5%) patients without prior surgery had complete relief of symptoms and one (12.5%) patient had partial relief, as opposed to complete relief in four of nine (44.4%), partial relief in one of nine (11.2%), and no relief in four of nine (44.4%) patients with a history of prior surgery. Because of the small number of patients, this difference was not statistically significant (P =.110). Eleven of 16 (68.8%) patients stated that the surgery was worthwhile. Eight of 16 (50%) patients felt they were more active and functional after surgery, whereas 25% felt they were either unchanged or less functional than before surgery. None of the patients without a history of prior surgery reported a decreased sense of functional activity following rhizotomy. CONCLUSION CT fluoroscopy-guided percutaneous cervical nerve block is useful for the confirmation of occipital neuralgia, for demonstrating to patients the sensory effects of nerve sectioning, and possibly as a guide for selection of patients for intradural cervical dorsal rhizotomy. Although not statistically significant, there was a trend toward better response to rhizotomy in patients without prior head or neck surgery.