Headaches in patients with radiosurgically treated occipital arteriovenousmalformations

Object. The goal of this study was to determine the prevalence, characteris tics, and radiosurgical outcomes of headaches associated with occipital art eriovenous malformations (AVMs). Methods. The authors reviewed the medical records of 37 consecutive patient s with occipital AVMs who had been treated by radiosurgery to identify the radiological features of the AVMs before and after treatment and the clinic al features and outcomes of headaches described in accordance with the crit eria of the International Headache Society (IHS). Thirty-six patients (97.3%) were followed for a mean period of 46.6 months. The median volume of the AVMs was 1.9 cm(3), to which a mean radiation dos e of 21.6 Gy was delivered. In the entire study group, periodic headaches w ere found in 17 patients (45.9%), of whom seven (18.9%) suffered from migra ines with the characteristic visual aura. Migraine was predominantly found in patients with right-sided (p = 0.038) or laterally located (p = 0.025) A VMs. Factors associated with a higher incidence of any type of headache inc luded larger nidus volume (p = 0.02), tortuous change of feeding artery (p = 0.036), and cortical drainage with reflux in the superior sagittal sinus (p = 0.032). The actuarial rate of angiographic obliteration was 71.6% at 3 years. Headaches resolved or improved in 12 (70.6%) of 17 patients, includ ing six (85.7%) of seven with migraine. The outcome of headache closely cor related with the obliteration results of the AVM (p = 0.002). Conclusions. A portion of occipital AVMs do cause headaches that satisfy th e current IHS criteria for migraine, and the prevalence varies by the topog raphy of the lesion. Radiosurgery can resolve headaches in the majority of treated patients.