Cluster headache and the sympathetic nerve

Objective.-To determine the effect of a sympathetic block at C7 on cluster headache. Backround.-Eleven patients presenting to a pain control unit with cluster headache were included in the study after giving informed consent. Methods.-In all patients, a mixture of 5 mL of 0.5% bupivacaine hydrochloride and I cc of methylprednisolone acetate was injected onto the base of the C7 transverse process. Results.-The injection was applied during the acute phase of headache in 6 patients and all experienced immediate and complete relief. The other 5 patients received the injection between attacks. Of the 11 patients treated, 8 went into remission by aborting the cluster. In some patients, repeated injections were given before the cluster was aborted. Three patients did not respond to treatment. One patient with chronic paroxysmal hemicrania experienced pain relief of the acute attack after treatment, but the procedure did not abort the subsequent attacks. A surgical sympathectomy removing the stellate ganglion rendered him pain-free for 15 months after which he was lost to follow-up. Conclusion.-Blocking the sympathetic nerve aborts an acute attack of cluster headache and may play a major role in aborting the cluster. Although only one patient with chronic paroxysmal hemicrania responded to surgical sympathectomy, this procedure may be considered as an alternative if there is poor response to oral medication or a sympathetic block.