cluster headaches

Hi I am hoping that someone can shed some light on this matter.

I have been a sufferer of Cluster Headaches for over 35 years.  This is immense pain and up to 6 attacks a day.  They love to creep in during the night - the night attacks are excrutiating, because by the time one wakes up - its toooo late, the pain has dug in.

I have had acupuncture a number of times over the years, by different acupuncturist.

Why is it that once the needles are inserted I will have a viscious attack within 5 to 10 mins?

  I know a little about acupuncture.  I understand that CH's are rare and difficult to treat, and they involve the hypothalamus, the pineal gland, trochlear nerve,trigeminal nerve and probably the oculamotor  nerve. But what would the needles be stimulating to bring on an attack.  I am too scared to try it again.