Scalp nerve blockade reduces pain after headframe placement in radiosurgery: A double blind, randomized clinical trial

Background: Patients undergoing stereotactic headframe placement for radiosurgery report that discomfort associated with the headframe often lasts for the duration of the treatment day (approximately 6 hours). We hypothesize that blockade of scalp nerves prior to headframe placement reduces the incidence of moderate to severe head pain during the entire treatment day. We describe a randomized, double-blind, placebo-controlled study of awake patients having radiosurgery for intracranial pathology that examines whether scalp nerve blockade and local anesthetic infiltration results in superior patient comfort versus infiltration alone. Methods: Twenty seven adult patients undergoing stereotactic radiosurgery were randomized to receive a nerve block with placebo or bupivacaine 0.5% with epinephrine. Supraorbital and greater occipital nerve blocks using blinded syringes were performed by the anesthesiologist in addition to subcutaneous infiltration of pin sites with lidocaine 1% by the surgeon. Pain was reported using 10 cm visual analog scales (VAS) at pre-specified time points during the treatment day. The primary outcome measure was the presence of pain scores classified as zero to mild pain (VAS <4) or moderate to severe pain (VAS ≥4). Results: 27 patients were randomized to placebo (n = 14) and nerve block (n = 13) groups. The proportion of moderate to severe pain measurements were significantly less in the nerve block group than the placebo group (4.9% vs. 24.1%; odds ratio, 0.166; 95% confidence interval 0.029- 0.955; p = 0.044). There were no adverse events. Conclusion: Scalp nerve block significantly decreased moderate to severe head pain in radiosurgery patients throughout the treatment day.