Welcome to the board Suzie. So glad to hear he's continuing with the diagnostic work ups. The fact the 02 works as well as it does, as well as the symptoms you've described, sure sounds like CH to me. But obviously, any sudden onset head pain necesitates a complete neuro work up. AWESOME the GP knew about 02, that's just unvelieveable good fortune. The fact is, there are hundreds of headache types, some which mimic CH, and it’s important to eliminate those before arriving at a firm diagnosis.
I’ve had CH for 33 years, they haven’t killed me yet! You need an organized approach to managing them so they don’t manage your life. I use a 3 pronged approach, many use a similar approach:
1: A good prevent med. A med I take daily, while on cycle, to reduce the number and intensity of my attacks. I use lithium, it blocks 60-70% of my attack. Verapamil is the most common first line prevent, topomax also has a loyal following. Some have to combine lithium and verapamil together to get relief.
2: A transitional med. Most prevents will take up to 2 weeks to become effective. I go on a prednisone taper, from 80 mg to zero over a two week period to give me a break while my prevent builds up. Prednisone will provide up to 100% relief for many CH’ers but is harsh on the system and should only be used for short periods of time.
3: An abortive therapy, the attack starts, now what? As he;s already discovered, oxygen is the closest thing to a miracle drug there is. It should be his first line abortive. Breathing pure 02 will abort an attack for me in less then 10 minutes, that’s completely pain free. Read this link when you get a chance as tweaking HOW he uses it will likely speed up his abort times:
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Imitrex nasal spray and injectables are very effective abortives. I use the injectables, they’re expensive, and I rarely use them, mostly just when I get caught away from the oxygen. The pill form generally works too slow to be effective for CH’ers.
For now, get some energy drinks. Rock Star, Monster, any containing the combo of caffeine and taurine, chug it down as fast as you can when you feel an attack starting. Many can abort or at least really reduce an attack using these. I drink one WITH my oxygen as it seems to speed up the abort time, AND it pushes back the re-attacks for me.
Great to hear he's already on the "Batch Regimen", the D-3. It's helping way too many people to just be coincidence.
Finally, visit our sister board for “alternative” treatment methods outside of mainstream medicine. As you’ll see from all the success stories on this board, there is something to it.
clusterbusters.com
Read everything you can on this board, if he is a CH’er, knowledge is his best ally. We’ll help you all we can. Bless your heart for being such an awesome supporter. I'd be dead without my wife!

Joe