Headaches that are caused by head or neck trauma are classified under 5. Headache attributed to trauma or injury to the head and/or neck. This is true in particular for post-whiplash headache, despite the likely possibility that these headaches are attributable to pathology in the neck. Neuralgiform headaches manifesting with facial, neck and/or head pain are classified under 13. Painful cranial neuropathies and other facial pains.
Primary or secondary headache or both?
When a headache occurs for the first time in close temporal relation to a cranial, cervical, facial, neck, eye, ear, sinus, dental or mouth disorder known to cause headache, it is coded as a secondary headache attributed to that disorder. This remains true when the new headache has the characteristics of any of the primary headache disorders classified in Part One of ICHD-3 (beta). When a pre-existing headache with the characteristics of a primary headache disorder becomes chronic, or is made significantly worse (usually meaning a two-fold or greater increase in frequency and/or severity), in close temporal relation to a cranial, cervical, facial, neck, eye, ear, sinus, dental or mouth disorder, both the initial headache diagnosis and a diagnosis of 11. Headache or facial pain attributed to disorder of the cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other facial or cervical structure (or one of its subtypes) should be given, provided that there is good evidence that that disorder can cause headache.
Disorders of the cervical spine and of other structures of the neck and head have not infrequently been regarded as common causes of headache, since many headaches seem to originate from the cervical, nuchal or occipital regions or are localized there. Degenerative changes in the cervical spine can be found in virtually all people over 40 years of age. However, large-scale controlled studies have shown that such changes are equally widespread among people with and people without headache. Spondylosis or osteochondrosis are therefore not conclusive as the explanation of headache. A similar situation applies to other widespread disorders: chronic sinusitis, temporomandibular disorders and refractive errors of the eyes.
Without specific criteria it would be possible for virtually any type of headache to be classified as 11. Headache or facial pain attributed to disorder of the cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other facial or cervical structure. It is not sufficient merely to list manifestations of headaches in order to define them, since these manifestations are not unique. The purpose of the criteria in this chapter is not to describe headaches in all their possible subforms, but rather to establish specific causal relationships between headaches and facial pain and the disorders of the cranium, neck, eyes, ears, nose, sinuses, teeth, mouth and other facial or cranial structures where these exist. For this reason it has been necessary to identify strict specific operational criteria for cervicogenic headache and other causes of headache described in this chapter. It is not possible here to take account of diagnostic tests that are unconfirmed or for which quality criteria have not been investigated. Instead, the aim of the revised criteria is to motivate the development of reliable and valid operational tests to establish specific causal relationships between headaches and craniocervical disorders.
For these reasons, and because of the variety of causative disorders dealt with in this chapter, it is difficult to describe a general set of criteria for headache and/or facial pain attributed to them. However, in most cases there is conformity with the following:
A. Headache or facial pain fulfilling criterion C
B. Clinical, laboratory and/or imaging evidence of a disorder or lesion of the cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other facial or cervical structure known to be able to cause headache
C. Evidence that the pain can be attributed to the disorder or lesion
D. Not better accounted for by another ICHD-3 diagnosis.