Headache Side Switch

[CaptChaos]

Anyone have experience with your pain switching sides during an episode? I understand it happens but in my 22 years of dealing with left-side CH I've only had two episodes of right-side headaches. One was an entire episode and the other was classified as a MOH due to excessive Imitrex usage. The MOH was taken care of with a strong Prednisone taper.

Anyway, after 7 weeks of continuous left-side CHs I had one night pain free then an unexpected shift to my right side. It switched about 8 days ago and I've had one nightly. All the typical symptoms of CH but more frequent and rebounding faster after O2 treatment. Imitrex seems to successfully abort without rebound. 

Just seemed odd to me. I had only used 5 imitrex shots in the month prior to the change so I don't suspect MOH. I've been burning through E tanks at 10m/l flow to preserve. It successfully aborts the headache after a few minutes but they always rebound. Tried doing 25 mins last night and rebounded with the most severe one to date. Going to stick with short use 02 for the time being but curious if I should expect a new CH episode with the switch or if it's possibly a sign the episode is finally coming to an end. I have the necessary means to "bust" if that seems appropriate to try. Appreciate your thoughts. 

For context: taking Verapamil 120mg 2x/day, no other preventatives.