As a surgeon with seasonal cluster headaches for six years, this season was by far the most severe and long lasting. No response to high dose steroids, Verapamil, Vit D 3, etc.
I had 82 Imitrex injections in 8 weeks. (I learned to cut them in half as per an old blog on this site.)
Out of desperation, my neurologist suggested I try a sub-occipital injection. This is not just an occipital nerve injection but an injection at under the base of the skull by a knowledgeable interventional radiologist. I was very skeptical.
While one case means nothing in medicine and while testimonials are frowned upon in medicine, I have to say it worked. I have had no headaches for two weeks. I still have some background shadow headaches which tells me my season is not over, but no further killer CH's as I was having having 2-4 a day.
Just one beggar telling another where he found help.
Consider asking your neurologist to review the literature on a sub-occipital injection.

When I read that nothing works I suggest exploring:

Link to: cluster-LIKE headache:

IN: "Medications, Treatments, Therapies --> "Important Topics" --> "Cluster-LIKE headache"

Bob Johnson wrote on Mar 23^rd, 2015 at 3:53pm:

When I read that nothing works I suggest exploring: Link to: cluster-LIKE headache: IN: "Medications, Treatments, Therapies --> "Important Topics" --> "Cluster-LIKE headache"

Oh good gosh - YES!

Hey Doc,

Bob has given you some good info on cluster-LIKE headache... 

There's also a good probability you're experiencing an allergic reaction to Spring pollen...  The pollen count is particularly onerous this year.

We've found allergic reactions can dump so much histamines into the bloodstream they make nearly all methods of CH intervention ineffective at best, and more likely, totally ineffective...

Check your PM inbox...  I've sent you some information you might find useful.

It's always a treat to have a physician in our midst so please take care and keep us posted...   

V/R, Batch