My 18 year old son has had 2 episodic cluster periods ( march 2016 x 3 weeks and sept 2016 x 2 weeks ) He was treated with prednisone and verapamil at onset. Oxygen was helpful the first time and not the second. He is allergic to triptans. He had sphenopalatine ganglion (SPG) block with 4% cocaine drip intranasal 10 days into the last cluster period. The SPG block did cut in half the length ( 25-30 min down to 15-18 min) in each of the final four headaches of his cluster period . The intensity was unchanged but each headache was absolutely shorter (He had 9:30 AM and 9:30 PM headaches so we could clearly track the length). As I anticipate he will have a new cluster period start in the next 2-3 week we will begin SPG blocks on day one or two and assess. I will report back when we see if this plan is helpful.