Postoperative headache following acoustic neuroma resection: occipital nerve injuries are associated with a treatable occipital neuralgia.

OBJECTIVE: To demonstrate that occipital nerve injury is associated with chronic postoperative headache in patients who have undergone acoustic neuroma excision and to determine whether occipital nerve excision is an effective treatment for these headaches.
BACKGROUND: Few previous reports have discussed the role of occipital nerve injury in the pathogenesis of the postoperative headache noted to commonly occur following the retrosigmoid approach to acoustic neuroma resection. No studies have supported a direct etiologic link between the two. The authors report on a series of acoustic neuroma patients with postoperative headache presenting as occipital neuralgia who were found to have occipital nerve injuries and were treated for chronic headache by excision of the injured nerves.
METHODS: Records were reviewed to identify patients who had undergone surgical excision of the greater and lesser occipital nerves for refractory chronic postoperative headache following acoustic neuroma resection. Primary outcomes examined were change in migraine headache index, change in number of pain medications used, continued use of narcotics, patient satisfaction, and change in quality of life. Follow-up was in clinic and via telephone interview.
RESULTS: Seven patients underwent excision of the greater and lesser occipital nerves. All met diagnostic criteria for occipital neuralgia and failed conservative management. Six of 7 patients experienced pain reduction of greater than 80% on the migraine index. Average pain medication use decreased from 6 to 2 per patient; 3 of 5 patients achieved independence from narcotics. Six patients experienced 80% or greater improvement in quality of life at an average follow-up of 32 months. There was one treatment failure. Occipital nerve neuroma or nerve entrapment was identified during surgery in all cases where treatment was successful but not in the treatment failure.
CONCLUSION: In contradistinction to previous reports, we have identified a subset of patients in whom the syndrome of postoperative headache appears directly related to the presence of occipital nerve injuries. In patients with postoperative headache meeting diagnostic criteria for occipital neuralgia, occipital nerve excision appears to provide relief of the headache syndrome and meaningful improvement in quality of life. Further studies are needed to confirm these results and to determine whether occipital nerve injury may present as headache types other than occipital neuralgia. These findings suggest that patients presenting with chronic postoperative headache should be screened for the presence of surgically treatable occipital nerve injuries.