Ultrasound Guided Infratemporal Sphenopalatine Ganglion Supravoltage Versus Standard Voltage Pulsed Radiofrequency for Pain Alleviation in Chronic Refractory Migraine.

Inclusion Criteria: * 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 Exclusion Criteria: * Medication Overuse Headache per ICHD-3: Simple analgesics (acetaminophen, NSAIDs, non-opioid analgesics) used on ≥15 days per month for \>3 months, OR Triptans, ergot derivatives, opioids, or combination analgesics used on ≥10 days per month for \>3 months. * Any secondary headache disorder ( cluster headache, hemiplegic migraine, migraine with brainstem aura (distinct pathophysiology); chronic tension-type headache \>10 days/month. * Any prior SPG block, PRF, radiofrequency thermocoagulation, chemical neurolysis, or neurostimulation of SPG/trigeminal system within 6 month. * No prior occipital or supra-orbital nerve radiofrequency, cryotherapy, or chemical neurolysis within 3 months * Use of botulinum toxin (Botox) within 3 months or CGRP monoclonal antibodies within 3 months prior to enrollment. * Active psychosis, bipolar disorder (current manic/depressive episode), severe depression with suicidal ideation, dementia, or substance use disorder (DSM-5 criteria) within 12 months; PHQ-9 ≥20 or cognitive impairment affecting reporting reliability. * Cardiac pacemaker, ICD, neurostimulator, or cochlear implant; or ECT. * Chronic uncontroled hypertension ; history of stroke, intracranial aneurysm, or high risk for cardiovascular events. * Pregnancy or lactation, Initiation, discontinuation, or modification of hormonal contraceptive therapy within 3 months prior to enrollment. Coagulopathy (platelets \<100,000 or INR \>1.5) or ongoing anticoagulation not safely withheld. -Patient refusal.