Cervicogenic headache: Location and source

By Jan Willem Elkhuizen

Where is the headache located?

The exact location of the headache can be an indication of where the cause is located. There are three types of experiences that provide an image of this:

• Experiments where headache patients are treated with local injections of an anesthetic. The place where the pain subsides is marked and linked to the tissue that is anesthetized.
• Experiments where healthy people are injected with a stimulating substance. The pain that then arises is linked to the injection site.
• Experiences of doctors and therapists in treating headache patients. If the pain subsides after treatment of, for example, a muscle or joint, this can be an indication that the source of the pain was indeed identified. Of course, there are placebo and other effects, but in the long term and with sufficiently large numbers, these practical experiences lead to more insight.

Based on the available data, the following picture can be sketched.

A. Pain stimuli from the soft tissues (muscles, tendons, attachments, etc.)

Explanation:
C0-1: Between the skull and the 1st vertebra (the atlas)
C1-2: Between the 1st and 2nd vertebra (atlas and axis)
C2-3: Between the 2nd and 3rd vertebra
C3-4: Between the 3rd and 4th vertebra

There is much overlap. Roughly, the trend is: The higher the source, the higher the pain ('higher' = more towards the forehead). The pain is basically one-sided, unless multiple muscles etc. are affected.

N.B.: The above image is derived from experimental research on healthy individuals where a pain-inducing substance was injected.

B. Pain stimuli from the joints

The projection area of the pain depends on the severity and the duration of the stimulation. As the complaints persist longer, the affected area often gradually expands.

With mild stimulation by injection of pain-provoking substance into the upper neck joints in healthy subjects, the expansion area is limited:

With persistent stimulation, the pain in patients can increase significantly and the area where the pain is felt becomes larger. This applies to all three segments. Below are some examples of pain areas reported by patients with chronic headache-from-the-neck:

Pain from the neck joints is basically one-sided, unless both joints (left and right) of a certain segment are affected.

C. Combinations of pain areas

There appears to be a lot of overlap in the pain areas from the different sources. This makes diagnosing based on the nature and location of the headache difficult. Additionally, a functional disorder within the C0-2 complex can also lead to functional disorders in the other joints within that complex, with the associated complaints. This makes it even less clear.

On top of that are the soft tissues. Functional disorders lead to changes in muscle tension, which can cause irritation of muscles, tendons, attachments, etc. When the patient visits a healthcare provider with their complaints, it is often a combination of tissues that together form the source of the complaints.

Underlying causes of cervicogenic headache

(Para)medics have traditionally been used to tracing a complaint back to the anatomical source. This can be, for example, a tendon (inflammation), a muscle (tear), an intervertebral disc (hernia), etc. Given the above, it is often difficult, if not impossible, to trace cervicogenic headache back to just one specific source. This is not surprising; experience shows that often multiple tissues are irritated simultaneously.

More useful than knowing exactly which muscle or joint is irritated is knowing what caused that irritation. By stepping back further than the 'anatomical source', a better understanding of cause-effect relationships can be gained. Muscles do not just become hard, joints do not just become stiff.

Although the anatomical source varies, a general connection can be made between some common stressful situations and the clinical picture that results.

I Overuse of C0-2 complex

A. In forward direction

This occurs with:

• schoolchildren who read bent forward a lot
• incorrect working postures
• watching TV slouched on the couch
• watching TV in bed
• reading in bed or lying back on the couch
• sleeping on the back with a pillow that is too high

This often leads to:

• Symmetrical complaints (approximately equal complaints on the left and right)
• Pressure in the head
• Band around
• Gradual increase of pressure in the head leading to chronic severe headache
• Looking upwards is often somewhat difficult and unpleasant
• Dizziness

Two examples of pain areas (if bilateral) that match these complaints:

In the initial phase, there is not much headache yet and the sensation is sometimes difficult to describe. Words used then include: a vague, dull feeling in almost the entire head. Notably, mobilization of the C0-2 complex, especially of C0-1, often has an immediate effect on the complaints. The headache usually quickly subsides, but sometimes there is a temporary worsening. After some time, the complaints return if the underlying causes are not resolved.

B. In lateral direction

.

This occurs with:

• Reading on the side with hand under the head
• Watching TV in side position
• Pillow too high or too low in side position

This leads to a less clear symptom picture than that of IA and II. Both symmetrical and asymmetrical symptoms can result. The type of symptoms also varies and cannot be easily summarized. It is notable that mobilization of the C0-2 complex, especially the lateral movement, quickly temporarily improves the symptoms. However, if the underlying causes are not resolved, the symptoms return quickly.

II Overuse of C2-3

This occurs with:

• Sleeping in the stable side position
• Pillow too high (in combination with the stable side position)

This often leads to:

• Asymmetrical symptoms (one-sided or one side clearly worse than the other)
• Pain 'shoots' from high in the neck up to above the eyes
• Pain above the eyes, with only minor and sometimes no neck symptoms at all
• Turning is sometimes slightly limited and a slight 'pulling sensation' occurs in the neck muscles

It is notable that the symptoms usually respond immediately to mobilization of C2-3. It also applies here that the symptoms return quickly if the underlying causes are not resolved.

Two examples of pain areas that match these symptoms:

The article 'Anatomical perspective on sleeping positions' goes deeper into the anatomical consequences of incorrect sleeping positions and provides more insight into the outlined symptom picture.

See also the pdf of the article about cervicogenic headache.