Insights – Anatomy of Headaches: Part 4 – The Upper Cervical Spine

The upper cervical spine is in the box seat to, at the very least be a major contributor to the over activity in the brainstem, if not to be the underlying cause, but is largely ignored by mainstream medicine.

Through the first 3 parts of this anatomy series we have shown the symptoms of headache and migraine are predominantly related to the trigeminal system. We also learned that the upper 3 cervical nerves intermingle with the trigeminal nerves in the trigemino-cervical nucleus (TCN) – the “relay station” for the information coming in from these nerves to the brain. In the last part we saw clear evidence that this relay station is overactive, not just in migraine, but also tension-type headache, menstrual migraine, cervicogenic headache and cluster headache.

All of this is well understood throughout the neurological community, and the anatomical pathways are accepted. What is a matter of debate is how much contribution the neck makes to headache and migraine. Up until the 1990 International Headache Society (IHS) classification of headache, cervicogenic headache was not recognized as an “official” headache type. At some levels of the neurological world, there is still debate as to whether cervicogenic headache really exists at all.

Since being recognised, the official prevalence rate has been reported as between 0.4-4% of the population, compared to migraine (15%) and tension type headache (30%). We believe cervicogenic headache is under-diagnosed and represents closer to 80% of headache sufferers. We are not alone in this view. Dr Peter Rothbart, director of a large headache treatment facility in Ontario Canada suggest the same rate:

“Approximately 800 new headache patients per year are examined at our clinic.  An estimated 80% of these patients are diagnosed with cervicogenic headache.  Of these patients, almost none are referred with this diagnosis.  Physicians are not taught to consider or explore neck structures when investigation headaches. This results in a rarely diagnosed but common condition” (1)

Is it a coincidence that around the same number, 81% are looking for more effective treatment?

The reason for the difference is that cervicogenic headache is not permitted to exist based on its outward symptoms the way migraine and tension headache do. It can’t. Clinically it often looks exactly the same as tension type headache or migraine. Even the president of the IHS admits:

“Headache of cervical origin and migraine often shows similar clinical presentations” (2) 

So migraine is classified and diagnosed on the way it looks.

In the clinic it can look identical to the headaches accepted to come from the cervical spine.

So how can doctors or neurologists know the difference without excluding the cervical spine?

Based on this alone I would argue that is sufficient cause to “Check your neck”.

For cervicogenic headache to prove its existence it must demonstrate clinical signs that implicate a source of pain in the neck (none have been sufficiently validated for the IHS to accept), or the headache is abolished following diagnostic blockade of pain referring structures in the upper cervical spine. Diagnostic blockades are not practical in the clinical setting, and it is extremely difficult to block every pain sensitive structure.

Firstly, each spinal nerve supplies two spinal joints, the segment above and below where it exits the spine. Secondly each joint has sensory nerves that originate from two spinal levels and there can be intermingling of levels for up to 3 spinal levels. It is possible that sensory information including pain can intermingle with the trigeminal nerve from as low as the C7 nerve root. (3)

So unless you block almost all the cervical nerves, this doesn’t appear a valid diagnostic tool for cervicogenic headache either.

Effectively, it becomes impossible to diagnose cervicogenic headache in anything but a laboratory – and even then, it’s debatable whether the methods are valid. Little wonder it barely exists – officially.

Even more confusing is that certain areas of neurology are now treating upper cervical nerves (Greater occipital nerve – branch of C2) with electrical stimulators and having some effect with migraine. In a recent podcast on the ABC Andrew Charles – Professor of Neurology at UCLA explained: (4)

"There is quite intense interest in the occipital nerves because they feed directly into some of these brain pathways we think are responsible for migraine. So there are actually now stimulator devices some people find helpful"

"There is growing recognition that the upper cervical nerve roots may actually be playing an equally important role and many, many migraine sufferers get neck pain before, during or after an attack."

On face value this might seem that the call of Dr Shevel is being heeded and the source of pain is being recognised, but unfortunately Professor Charles then goes on to say:

"This leads many people to seek chiropractic treatment or massage when in fact really this is just a symptom of their migraine, and if you effectively treat the migraine, the neck pain goes away."

Actually, it’s not a fact. That would suggest there is proof that the neck doesn’t refer headaches. There is no such proof. He also just finished saying treating the occipital nerve (C2 spinal nerve) with a stimulator was helpful for some?

To me this sounds half pregnant.

If you had leg pain and numbness in your foot that coincided with back pain, the first place to look would be your back. If your therapist said “we are going to treat the pain and numbness in the leg, and the back pain will just go” that you may well seek a second opinion.

Yes, it is possible for foot and leg problems to cause back pain, but it is far more common in the other direction – at the very least you wouldn’t rule the back out without checking it. That is exactly what Professor Charles would like you to do………81% continue to search for more effective treatment.

So without any supporting evidence to rule out the neck it is, again, brushed aside as irrelevant. Despite the obvious anatomical links, despite the overwhelming number of pain producing structures in the cervical spine, and despite the tick of approval for "stimulators" treating cervical nerves, any other form of neck treatment should not be considered.

Seriously? This makes no sense to me. If it does to you please post and let me know.

Little wonder we are sitting at under 20% satisfied with their current treatment when such an obvious source of pain referral is ignored.

The evidence is clear.

Check your neck with an expert at a dedicated clinic. The sooner the better.

I would like to note that I don’t believe ALL headache or migraine arises from the neck. I’ll agree with Dr Rothbart and settle for 80%.

(1) Rothbart P. The cervicogenic headache: A pain in the neck. Can J Diagnos 1996; 13: 64–71.

(2) Goadsby PJ, Bartsch T  Anatomy and physiology of pain referral patterns in primary and cervicogenic headache disorders.  Headache Currents 2005;10:42-48.

(3) Antonaci, F. Cervicogenic Headache: Consideration of pathogenesis. Chapter 11, in Tension Type and Cervicogenic Headache; pathophysiology, diagnosis and management.

(4) http://www.abc.net.au/radionational/programs/healthreport/migraine-research/4039834