Ultrasound Guided Sphenopalatine Ganglion Supravoltage Versus Standard Voltage Pulsed Radiofrequency for Pain Alleviation in Chronic Refractory Migraine. Randomized Double Blind Study
* PRF performed on the sphenopalatine ganglion level under ultrasound guidance. * Standard voltage PRF parameters: 45 V, 5 Hz frequency, 5 ms pulse width, 360 seconds duration, electrode temperature ≤42°C. * Supravoltage PRF parameters: Higher voltage than standard (e.g., 60-70 V), with same frequency, pulse width, and duration, maintaining temperature ≤42°C to avoid nerve damage.
• Diagnosis of chronic migraine according to International Classification of Headache Disorders criteria (≥15 headache days/month for \>3 months, including ≥8 migraine days/month) documented by Completion of 4-week prospective baseline headache diary immediately preceding randomization
‣ Failure of ≥2 classes of preventive pharmacological migraine medications (e.g., beta-blockers, antiepileptics, antidepressants...) to get clinically meaningful response ( defined as ≥50% reduction in monthly migraine days), at standard therapeutic doses (Beta-blockers (e.g., propranolol ≥160 mg/day, metoprolol ≥100 mg/day, Antiepileptics (e.g., topiramate ≥100 mg/day, valproate ≥500 mg/day, Tricyclic antidepressants (e.g., amitriptyline ≥50 mg/day, SNRIs (e.g., venlafaxine ≥150 mg/day ) for at least 8 weeks or ≥12 weeks in case of CGRP ).
⁃ Stable preventive migraine therapy for at least 4 weeks prior to enrollment.
⁃ MIDAS score ≥11 indicating moderate to severe disability.
⁃ Ability and willingness to maintain a daily headache diary throughout the study period.
⁃ Ability to provide written informed consent. Positive response (≥50% pain reduction within 30-60 minutes) to diagnostic INFRATEMPORAL sphenopalatine ganglion block using 2% lidocaine (2 mL) infrazygomatic approach