Migraine

There may be muscle soreness and tension on that same side, and a patient's neck and head mobility will be restricted. "They felt that the relationship was primarily associated with C2 and C3 facet joints in the neck-not in the disc," Dr. McClelland continues. "Their conclusions were strongly supported by the work of Nicholai Bogduk, a researcher and neurologist in Australia, who found that injections into the C2/C3 facet joints could actually block suboccipital headache in 70 percent of the trials he conducted. The IHS ranked cervicogenic headache as occurring much less frequently than tension or migraine headaches."

New Research, New Relationships

More recent work by neurologist Dr. Peter Rothbart, however, proposes that many tension and migraine headaches have a much more common relationship to the cervical spine.' Rothbart found that as many as 80 percent of the headaches he saw in his neurology center were neck-related headaches that had been previously diagnosed as tension or migraine headaches. Rothbart recently helped found the North American Cervicogenic Headache Society to further pursue these studies.
Dr. McClelland reports that findings such as these are prompting new attitudes about the source and treatment of migraine headaches. "There appears to be a discrepancy now developing between cervicogenic and what we might call vertebrogenic headaches that appear to be different from this C2/C3 facet-joint involvement." Dr. McClelland says that there is a trend developing among researchers to look at different aspects of neck involvement with headache-other than just the cervicogenic involvement.

The Tension - Migraine Mechanism

A current concept relative to tension - migraine headaches holds that they are not two separate kinds of headaches, but that they lie, instead, along a continuum. In other words, what were previously referred as two different types of headaches, and therefore treated differently, are more related than previously thought.
Intriguing new findings suggest other relationships between the neck and the tension - migraine mechanism and the central nervous system. "A relationship has been determined where nerve processes coming from either the trigeminal system or the cervical spine, especially the upper levels, Cl-C3, seem to tie together in the trigeminal nucleus and the posterior horn," Dr. McClelland says. "In turn, they send a second-order neuron structure that runs up and down the spinal cord and are functionally indistinguishable.

Researchers now believe there is such a close relationship to these two tie-ins that it is impossible at times to determine whether it is coming from the facial area or the neck area."

A new muscle relationship involving the rectus capitis posterior minor (RCPM) was inadvertently discovered in 1996 while Dr. Gary Hack, DDS, was performing cadaveric dissection in the posterior base of the skull-between the occiput and the first vertebra in the neck. "They found that there seemed to be some type of tissue relationship between that muscle, which attached from the occiput down to C1, with a 'bridge' to the dura mater," Dr. McClelland explains. "When people are sitting at their computers for long periods of time, with heads tilted forward, they are constantly stretching that muscle, which creates a potential tension build-up in the muscle that also has a relationship with the dura mater because of its tissue 'bridge.' They reasoned that perhaps the headache is more mechanical in nature because of constant stress to the muscle that causes a stress or tension on the dura mater-and that could bring about the headache."

"They have also learned," says Dr. McClelland, "that there may be other tie-ins, such as with the rectus capitis major and the obliquus capitis inferior, located betxveen Cl and C2. Researchers are starting to question the number of tie-ins to the central nervous system relative to perivertebral muscles. When you start looking at these relationships, you realize that anything that changes the mechanics of that upper part of the neck or base of the skull can have a dynamic relationship to headache control."

Effectiveness of Spinal Manipulation

Research to date has established that spinal manipulation does alleviate headaches, especially those of the tension -migraine variety. While manipulation may not be able to immediately reduce all the inflammatory changes and effects that the headache has caused, that condition frequently will stabilize enough overnight to show improvement the following day. There is also evidence that the use of cervical manipulation may offer a more lasting impact on keeping headaches under control.

Additionally, recent research contains evidence that manipulation has a prophylactic effect on headache development by apparently restoring normal joint function and muscle relaxation in the neck and upper back area. Drs. Pat Boline and Craig Nelson at Northwestern Chiropractic College have conducted two studies on tension and migraine detailed in the article below. "Researchers at the RAND Corporation performed a meta-analysis4 on the existing randomized controlled trials (RCTs) that pertain to treatment of neck pain and headache," Dr. McClelland adds. "They evaluated 14 RCTs and ranked the Boline study on tension headache highest, relative to the quality of the research."

Dr. McClelland reports that other studies of note include "Roentgenographic Findings of the Cervical Spine in Tension-Type Headaches" by Dr. A. Nagasawa.5 Dr. Nagasawa found a significant prevalence of the loss of the lordotic curve in people with chronic tension migraine headaches. Another ongoing study by Dr. Niels Nilsson, published in the Journal of Manipulative anJ Physlogtcal Therapeuti,' showed that when he compared the treatment of cervicogenic headache using spinal manipulation (SMT) versus softtissue massage and other interventions, the use of analgesic medications decreased 36 percent in five weeks with the SMT patients, whereas the soft tissue patients had no decrease. The headache intensity also decreased 36 percent versus 17 percent, and the headache hours per day decreased as much as 69 percent versus 37 percent.

Dr. McClelland asserts that research is bringing a better understanding of how spinal manipulation relieves migraine headaches.

"When a patient comes in with an acute tension or migraine headache that has been pounding for three or four days," Dr. McClelland continues, "after he is manipulated, he may feel a little better before leaving the office, and by night or the next morning the headache is gone. Was that a coincidence, or did I make a change for that patient? If so, what was