Ultrasound Guided Block of Stellate Ganglion Versus Greater Occipital Nerve in Resistant Migraine and Correlation to Calcitonin Gene Related Peptide

40 Patients diagnosed with Chronic resistant migraine to 2 anti-migraine drugs for 3 months will be evaluated for inclusion and exclusion. Eligible patients with resistance or intolerability to 2 drugs or more will be classified into two groups by using simple randomization methods through Using a computer-generated random number sequence. Each group will contain 20 patients one group will undergo ultrasound guided bilateral Greater Occipital nerve Block and the other group will undergo ultrasound guided bilateral Stellate Ganglion Block