I don’t want to type for ages here, but as someone who has been a sufferer and then medical patient for chronic daily migraines for decades; it actually is pretty nuanced.
For people like me, their chronic migraines are triggered as a secondary effect from the primary source. My headaches are called cervicogenic headaches, and migraine abortives like Obrelvy or Triptans are often used to arrest the storm. However, they are caused in origin from the occipital nerve, of which there are 3 branches in the neck.
An occipital nerve block is one commonly used tool, but it is often down blind without ultrasound. It is effective as hell at stopping migraine pain, and headache pain from what is the irritation or entrapment of occipital nerves. It has been common practice for several neuro and pain clinics I have seen for the last 2 decades. Problematically, they are not often offered in the emergency room setting because they are rather specialized procedures that usually are done by a neurology or trained pain physician. So that makes the emergency department a place that you go when the pain has overwhelmed all your other medications and resources, only to be met by not being able to get the one procedure that offers guaranteed relief for up to 2 weeks if given the block with steroids as well as local anesthetic. Frustrating to say the least, since you can plan on when you will get a massive headache, but you have to schedule to procedure weeks to months out with specialists.
Other migraine or occipital neuralgia triggering migraine treatments include other more invasive procedures to the nerves called ablations. Because cutting he nerve or surgically modifying them would result in scar tissue that would cause more problems or block regrowth, occipital ablations involve a needle slowly guided into the nerve under ultrasound imaging, and then they push electrical current into the needle while it is moved around by the provider. These can’t be numbed because you have to give feedback on where the currents are flowing in order to get it properly placed. Hurts like medieval torture. Then once placed they turn in ultrasonic pulses that heat the tip of the needle inside the nerve. This gets the tip hot enough to denature the nerve cells and kill them without harming the nerve sheath and allowing regrowth without nerve pain. It’s torture though and must be scheduled every 6-12 months. It doesn’t treat acute attacks, and can’t help with all types of headaches.
So offerings in the medical community pushed from specialized scheduled care to the responsive emergency providers as accepted medical interventions can be a massive improvement in accessibility to a treatment that can offer relief when no other physical interventions are reasonably possible for rapid abortive relief.