A new review article "Peripheral Nerve Blocks and Trigger Point Injections in Headache Management - A Systematic Review and Suggestions for Future Research." (PubMed abstract below) discusses the use of peripheral nerve blocks and trigger point injections in the treatment of headaches.
It is widely accepted that almost all headaches wether classified as vascular, neurogenic , hormonal or muscular in orgins are caused primarily by the Trigeminal Nervous system.
A study in the November issue of Headache concluded that migraineurs believe that having their physicians explain what physician what causes their headaches is extremely important. They also believe it is essential that they have the pathophysiology and triggers explained to them in lay terms by their physicians.