I have been diagnosed with reversible vasoconstriction syndrome, I was told it would subside around three months,it has now been going on your nearly 6 months. I am being treated with isoptin, the doctor was slowing reducing the dose over a 3weeks period. I was down too 180mg every second day. I have had another attack of severe headache, nothing like the thunderclap headaches I had earlier. The doctor has put be back on 280mg Isoptin and 12mg ended...I had had shingles to the head 1 month prior to having the Thunderclap headaches.My question is would having shingles bought this condition on?