Headache causally associated with cervical myofascial pain sources (myofascial trigger points) may, if it meets other criteria, be coded as 2.1.1 Infrequent episodic tension-type headache associated with pericranial tenderness, 2.2.1 Frequent episodic tension-type headache associated with pericranial tenderness or 2.3.1 Chronic tension-type headache associated with pericranial tenderness. It seems appropriate to add an Appendix diagnosis A11.2.5 Headache attributed to cervical myofascial pain, and await evidence that this type of headache is more closely related to other cervicogenic headaches than to 2. Tension-type headache. Clearly, there are many cases which overlap these two categories, for which diagnosis can be challenging.
Headache caused by a disorder of the cervical spine and its component bony, disc and/or soft tissue elements, usually but not invariably accompanied by neck pain.
A. Any headache fulfilling criterion C
B. Clinical, laboratory and/or imaging evidence of a disorder or lesion within the cervical spine or soft tissues of the neck, known to be able to cause headache
C. Evidence of causation demonstrated by at least two of the following:
1. headache has developed in temporal relation to the onset of the cervical disorder or appearance of the lesion
2. headache has significantly improved or resolved in parallel with improvement in or resolution of the cervical disorder or lesion
3. cervical range of motion is reduced and headache is made significantly worse by provocative manœuvres
4. headache is abolished following diagnostic blockade of a cervical structure or its nerve supply
D. Not better accounted for by another ICHD-3 diagnosis.
Features that tend to distinguish 11.2.1 Cervicogenic headache from 1. Migraine and 2. Tension-type headache include side-locked pain, provocation of typical headache by digital pressure on neck muscles and by head movement, and posterior-to-anterior radiation of pain. However, while these may be features of 11.2.1 Cervicogenic headache, they are not unique to it, and they do not necessarily define causal relationships. Migrainous features such as nausea, vomiting and photo/phonophobia may be present with 11.2.1 Cervicogenic headache, although to a generally lesser degree than in 1. Migraine, and may differentiate some cases from 2. Tension-type headache.
Tumours, fractures, infections and rheumatoid arthritis of the upper cervical spine have not been validated formally as causes of headache, but are nevertheless accepted as such when demonstrated to be so in individual cases. Cervical spondylosis and osteochondritis may or may not be valid causes fulfilling criterion B, depending on the individual case. When cervical myofascial pain is the cause, the headache should probably be coded under 2. Tension-type headache. However, awaiting further evidence, an alternative diagnosis of A11.2.5 Headache attributed to cervical myofascial pain is included in the Appendix.
Headache caused by upper cervical radiculopathy has been postulated and, considering the now well-understood convergence between upper cervical and trigeminal nociception, this is a logical cause of headache. Pending further evidence, this diagnosis is found in the Appendix as A11.2.4 Headache attributed to upper cervical radiculopathy.