Abstract Body: Background and Purpose: We report short- and intermediate-term effects on headaches with intra-arterial injection of lidocaine in the middle meningeal artery in patients with severe headaches associated with subarachnoid hemorrhage.

Methods: We treated 7 patients with intra-arterial lidocaine in doses up to 50 mg in each middle meningeal artery via a microcatheter bilaterally (except in one patient). We recorded the maximum intensity of headache (graded by 11-point numeric rating scale) prior to procedure and every day for the next 10 days or discharge, whichever came first. We identified changes in the middle meningeal artery pre- and post-intra-arterial lidocaine administration and quantified from Grade 0 (no change) to Grade 5 (severe narrowing or near occlusion of anterior and posterior dural branches or proximal middle meningeal artery that precludes adequate imaging of distal branches).

Results: We observed improvement in severity of headaches of headache in all 7 subarachnoid hemorrhage patients. The resolution of headache was immediate and complete in 4 patients, unilateral immediate resolution in one patient, and delayed complete resolution in patient. Only one patient met the definition of severe headache (defined as 2 or more days with maximum pain scores of 8 or greater or need for 3 or more different analgesics for 2 or more days) post treatment on Days 4 and 5. One patient had a relapse in headache with the severity matching pre-treatment severity and required a second treatment. On analysis of angiographic data, there was consistent narrowing of middle meningeal arteries after administration of intra-arterial lidocaine and was graded as 5 in 2 arteries, 4 in 10 arteries, and 3 in 2 arteries.

Conclusions: We found that intra-arterial injection of lidocaine can result in consistent amelioration of headache in patients with subarachnoid hemorrhage. The therapeutic benefit may be related to vasoconstriction (reversal of vasodilation) in the middle meningeal arteries after administration of lidocaine.