intra-arterial sphenopalatine ganglion block for patients with refractory headache

Conditions: Chronic Migraine; Cluster Headache; Trigeminal Neuralgia

Summary: the purpose of this study is to evaluate the safety and efficacy of intra-arterial (ia) delivery of dexamethasone and ketorolac into the arteries supplying the sphenopalatine ganglion (spg) - a collection of neurons that plays an important role in headache disorders - in patients with refractory migraine, cluster headache and trigeminal neuralgia. all patients must fail standard treatments prior to enrollment in the trial.

the investigators propose an outpatient, minimally invasive method to deliver dexamethasone and ketorolac to the spg via the intra-arterial route. a microcatheter will be advanced via the radial (preferably) or the femoral artery (in case the radial approach is not feasible) using fluoroscopic guidance and standard interventional techniques, into the distal internal maxillary artery. this artery is a branch of the external carotid artery and supplies the territory of the sphenopalatine ganglion. the microcatheter will be advanced to the ostium of the distal small branches that supply the spg (i.e. small arteries feeding the vasa nervosum). once the microcatheter is in a good position, 15 mg dexamethasone sodium phosphate and 15 mg of ketorolac tromethamine will be infused over 30 minutes. the procedure will be performed with local anesthetic at the arterial puncture site. conscious sedation will be used for anxious participants. after the procedure, the participant will be observed for 5 hours in icu setting and then discharged to home. the procedure will be performed unilaterally for participants with cluster headache and trigeminal neuralgia. the procedure could be performed bilaterally for participants with migraine.

Eligibility criteria:
inclusion criteria: * established diagnosis of one of the three following headache or facial pain disorders as defined by the ichd-329 \[chronic migraine, cluster headache, trigeminal neuralgia\] and failure to respond to two or more preventive therapies a. chronic migraine failure to respond to two or more preventive therapies including onabotulinumtoxin a, erenumab, fremanezumab, galcanezumab, topiramate, valproic acid, metoprolol, propranolol, timolol, atenolol, nadolol, amitriptyline, nortriptyline, venlafaxine, duloxetine. this will include status migrainosus. b. cluster headache failure to respond to verapamil, and one other preventive treatment including prednisone, dexamethasone, galcanezumab, lithium, valproic acid, topiramate, external vagus nerve stimulation c. trigeminal neuralgia failure to respond to two or more preventive therapies, including: oxcarbazepine or carbamazepine, and one of the following: gabapentin, pregabalin, baclofen, lamotrigine, phenytoin exclusion criteria: * patients with malignant neoplasm of the pterygopalatine fossa * pregnancy, lactation * severe allergic reaction to dexamethasone * severe allergic reaction to nsaid * renal failure * active systemic infection or fever * known cerebral vascular disease * drug or alcohol abuse * opioid dependency (stable doses ok) * triptans within 48 hours from the procedure