The treatment of chronic incisional pain and headache after retromastoid craniectomy

BACKGROUND: A seldom emphasized complication of retromastoid craniectomy is chronic postcraniectomy incisional pain or headache. Although hypotheses have been proposed to explain this problem, there have been few attempts to treat patients in a delayed fashion. The results of postoperative treatments for chronic postretromastoid craniectomy pain and their rationales are discussed in a preliminary number of patients. METHODS: Eight patients with chronic postretromastoid craniectomy pain who did not have placement of a cranioplasty at their initial operation underwent placement of a methylmethacrylate cranioplasty as a separate procedure. Three additional patients who did have a cranioplasty, but who had chronic pain underwent selective blocking of the ipsilateral second cervical nerve. If blocks resulted in relief of pain they then underwent a dorsal rhizotomy or ganglionectomy. RESULTS: Two of the eight patients undergoing a cranioplasty had excellent results and one partial improvement while five failed at last follow-up. The three patients with a cranioplasty representing four symptomatic sides underwent a dorsal rhizotomy or ganglionectomy after a positive selective cervical nerve blocking. All four operations resulted in excellent relief with one side failing 3 months postop after a motor vehicle accident. CONCLUSION: Chronic headache or incisional pain after retromastoid craniectomy remains a significant complication of the operation. The patients presented here support the contention that multiple etiologies may play a role. Pain caused by scalp to dura adhesions can be treated effectively with a simple cranioplasty while occipital nerve injury can be identified using selective second cervical nerve blocking, and long-term relief obtained with a dorsal rhizotomy or ganglionectomy.