Deep Cervical Plexus Block for the Treatment of Cervicogenic Headache

Abstract

Background: Cervicogenic headache descriptors include its unilateral nature, “signs and symptoms linking it to the neck,” and trauma of the neck. Since the pain often occurs over the C2 or C3 nerve root, we used a modification of the deep cervical block technique for treatment of this refractory type headache. Objective: To determine the efficacy of a modified deep cervical block for treatment of cervicogenic headache. Design: Prospective case study. Methods: Thirty-nine patients referred to our pain clinic participated in this study. All patients had undergone extensive screening/diagnostic testing. The blocks were performed unilaterally, without inducing a risk of invading the neural foramen, and repeat injection of the contra-lateral side occurred at >1 week after initial injection. Patients were followed for a 6-month period using a pain diary and questionnaire. Pain was assessed pre- and post-injection and 3 and 6 months post treatments. Results: The mean treatment period was 59 ± 61 days. The mean values for pre- and post-injection series pain scores (0–10 pain scale) were 9.54 ± 1.53 and 6.75 ± 3.23 respectively (p < 0.001). Thirty-three percent (33%) of the patients reported pain scores of ≤ 4 on the 0-10 pain scale after their last treatment. Effectiveness of the therapy following the injection procedure was rated to be 42% effective for all first injections and 40% effective for last injections (p =NS). Six months evaluations showed that return of moderate to severe pain took 6.62 ± 8.1 weeks. At the 3 and 6 months follow up evaluations, mean pain scores had returned to 8.41 ± 2.96 and 8.83 ± 2.78, respectively. Ten patients (24%) had pain scores ≤ 4 at the 3-month evaluation while 7 of the patients (18%) had pain scores ≤ 4 at the 6-month evaluation. Conclusions: These results showed that for some patients this series of blocks provided effective pain relief for 3 months post treatment but by 6 months the pain had returned to pre-treatment levels. This block technique significantly diminished pain after the initial as well as the last treatment. These clinically significant changes in pain relief suggest that more aggressive selective therapy targeting these nerve routes might provide longer lasting relief. Key words: Cervicogenic headache, deep cervical block, chronic pain