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.