Jeebs,
My recollection is that my daughter's first bad cycle followed a tooth extraction, when she had only had occasional "bad headaches" before that time. The extraction itself was difficult, and for a long time we were blaming the dentist for having caused her CH (which at that time (and for much too long thereafter) was diagnosed as trigeminal neuralgia). I don't remember specifically whether she was having those "headaches" at the time of the extraction, so I'm not fully answering your question, but the shift in severity was very large.