Posterior meningeal artery DMSO injection resulting in reproducible asystole prior to Onyx therapy of a dural arteriovenous fistula: a previously undescribed variant of the trigeminocardiac reflex or a new phenomenon?

We describe a case of reproducible asystole during endovascular treatment of a posterior fossa dural arteriovenous fistula. Catheterisation of the posterior meningeal artery, a branch of the vertebral artery in this patient, followed by dimethyl sulfoxide injection prior to Onyx administration resulted in two episodes of asystole.To the best of our knowledge, this is the first reported case of asystole occurring during endovascular intervention in the posterior meningeal artery.