A. Any new headache fulfilling criterion C
B. Radiosurgery of the brain has been performed
C. Evidence of causation demonstrated by both of the following:
1. headache has developed within 7 days after radiosurgery
2. headache has resolved within 3 months after radiosurgery
D. Not better accounted for by another ICHD-3 diagnosis.
Although de novo headache has been described after radiosurgery, most studies do not provide detailed descriptions of its clinical characteristics, neither is it usually clear whether headache occurring after radiosurgery represents an exacerbation of an underlying headache disorder or a new headache. In cases where a previous history of headache was not present, the headache syndrome was short-lived, occurred more than a year after the procedure, and resembled migraine or thunderclap headache. Therefore, causal relationships between these headaches and the radiosurgical procedures preceding them were highly doubtful. Carefully controlled prospective studies are necessary to determine whether A5.7 Headache attributed to radiosurgery of the brain exists as an entity and, if so, how it is related to the type and location of the lesion being irradiated and/or the dosage and radiation field employed.