The goal of this clinical trial is to compare two different types of occipital nerve stimulation (BurstDR (dorsal root) microdosing versus Tonic) in chronic refractory migraine. The main questions it aims to answer is whether BurstDR microdosing is effective in reducing moderate to severe headache days compared to Tonic stimulation (which is currently in use). Additionally, the safety of both types of stimulation will be studied.
Participants will be asked to keep a headache diary, then have the device implanted and programmed, and keep a subsequent headache diary to see if there is an improvement in their headaches after three moths of stimulation. If they don't respond to treatment, they will be allowed to swap to the other type of stimulation to see if this improves their symptoms.