CERVICOGENIC HEADACHE

Samer Narouze, MD, MSc, DABPM, FIPP

Cervicogenic headache was initially defined as unilateral

headache that is provoked by neck movement or pressure

over tender points in the neck with associated reduced

range of movement of the cervical spine. The headache

occurs in nonclustering episodes and is usually nonthrob-

bing in nature, originating from the neck, and spreading

over the head.'? It is sometimes difficult to differentiate

among cervicogenic headache, migraine, and tension-type

headache based only on the clinical presentation.+¢ How-

ever, diagnostic blockade of the nerve supply of these

cervical structures or intra-articular injection of local anes-

thetic into the affected joint help establish the diagnosis; in

fact, this is now considered a major criterion for the diag-

nosis of cervicogenic headache.’ Also, it was long thought

that cervicogenic headache should be only unilateral, but

recent reports state that cervicogenic headache can be

either unilateral or bilateral.’

These clinical findings prompted the development of the

new diagnostic criteria for cervicogenic headache by the

International Headache Society (IHS) in 2004, as follows:*

A. Pain, referred from a source in the neck and per-

ceived in one or more regions of the head and/or

face, fulfills criteria C and D.

B. Clinical, laboratory, and/or imaging evidence of

a disorder or lesion within the cervical spine or soft

tissues of the neck is known to be, or generally

accepted as, a valid cause of headache.

C. There is evidence that the pain can be attributed to

the neck disorder or lesion based on at least one of

the following:

1. Demonstration of clinical signs that implicate a

source of pain in the neck.

2. Abolition of headache following diagnostic block

of a cervical structure or its nerve supply using

placebo or other adequate controls. Abolition of

headache means complete relief of headache,

indicated by a score of 0 on a visual analog scale.

D. Pain resolves within 3 months after successful treat-

ment of the causative disorder or lesion.

Clinical signs acceptable for criterion C1 must have dem-

onstrated reliability and validity. Clinical features such as neck

pain, focal neck tenderness, history of neck trauma, mechani-

cal exacerbation of pain, unilaterality, coexisting shoulder

pain, and reduced range of motion in the neck are not unique

to cervicogenic headache. These may be features of cervico-

genic headache, but they do not define the relationship be-

tween the disorder and the source of the headache.

ETIOLOGY

Cervicogenic headache is referred pain from cervical

structures innervated by the upper three cervical spinal

nerves. Thus possible sources of cervicogenic headache

278

are: atlanto-occipital joint, atlantoaxial (AA) joints, C2—C3

zygapophysial joint, C2—C3 intervertebral disc, and upper

cervical spinal nerves and roots. Other serious causes

of occipital headaches should be ruled out, such as poste-

rior cranial fossa lesions and vertebral artery dissection

or aneurysm.?

‘Tumors, fractures, infections, and rheumatoid arthritis

of the upper cervical spine have not been validated for-

mally as causes of headache, but are nevertheless accepted

as valid causes in individual cases.

Cervical spondylosis and osteochondritis are not ac-

cepted as valid causes of cervicogenic headache. Also, when

myofascial tender points are the cause, the headache

should be coded under tension-type headache.

NEUROANATOMY

AND NEUROPHYSIOLOGY

The spinal nucleus of the trigeminal nerve extends cau-

dally to the outer lamina of the dorsal horn of the upper

three to four cervical spinal segments. This is known as the

trigeminocervical nucleus, which receives afferents from

the trigeminal nerve as well as the upper three cervical

spinal nerves. Convergence between these afferents ac-

counts for the cervical-trigeminal pain referral. Therefore,

pain originating from cervical structures supplied by the

upper cervical spinal nerves could be perceived in areas

innervated by the trigeminal nerve branches such as the

orbit and the frontotemporoparietal region (Fig. 41-1).

The concept of the trigemiocervical convergence was

well demonstrated by showing that noxious stimulation of

the greater occipital nerve increases central excitability

of supratentorial afferents,!? and stimulation of the dura

mater increases trigeminocervical neuron responsiveness

to cervical input.!!

COMMON SOURCES

OF CERVICOGENIC HEADACHE

ATLANTOAXIAL JOINT

The lateral atlantoaxial joint (AAJ) may account for up to

16% of patients with occipital headache.!’ Distending the

atlantoaxial joint with a contrast agent was shown to pro-

duce occipital pain, and injection of local anesthetic into

the joint relieves the pain.!?" Clinical presentations sug-

gestive of pain originating from the lateral atlantoaxial

joint include occipital or suboccipital pain, focal tender-

ness over the suboccipital area, restricted painful rotation

of Cl on C2, and pain provocation by passive rotation of

C1. These clinical presentations are not specific and there-

fore cannot be used alone to establish the diagnosis.’ The

only means of establishing a likely diagnosis is a diagnostic

block with intra-articular injection of local anesthetic."

The pathology of lateral atlantoaxial joint pain is usually

Supraorbital N. Occipital N.

Trigeminal X

Nucleus Caudalis \

& 1

SY)

C, Spinal N.

Co Spinal N.

G3 Spinal N.

FIGURE 41-1 The trigemino-cervical complex. (Reprinted with

permission from Cleveland Clinic)

post-traumatic or osteoarthritis.'+!5 However, the pres-

ence of osteoarthritic changes on imaging studies does not

mean that the joint is necessary painful. On the other

hand, the absence of abnormal findings on imaging studies

does not preclude the joint from being painful.

Intra-articular steroids are effective in the short-term

pain relief originating from the lateral atlantoaxial joint.!6!7

One report showed favorable long-term outcome after

both pulsed and thermal radiofrequency lesioning of the

AAJ capsule.!® In intractable cases not responsive to more

conservative management, arthrodesis of the lateral atlan-

toaxial joint may be indicated.!°

Atlantoaxial joint intra-articular injection has the poten-

tial for serious complications, so it is crucial to be familiar

with the anatomy of the joint in relation to the surrounding

vascular and neural structures (Fig. 41-2). The vertebral

artery is lateral to the atlantoaxial joint as it courses through

the C2 and C1 foramina. Then it curves medially to go

through the foramen magnum crossing the medial poste-

rior aspect of the atlanto-occipital joint (Fig. 41-2). The C2

dorsal root ganglion and nerve root with its surrounding

dural sleeve crosses the posterior aspect of the middle of

the joint. Therefore, during atlantoaxial joint injection, the

needle should be directed toward the posterolateral aspect

of the joint. This will avoid injury to the C2 nerve root

medially or the vertebral artery laterally (Figs. 41-3 through

41-5).-"" Meticulous attention should be paid to avoid in-

travascular injection because the anatomy may be variable.

Injection of a contrast agent should be performed under

real-time fluoroscopy, preferably with digital subtraction,

prior to the injection of the local anesthetic, as negative

aspiration is of low sensitivity. Inadvertent puncture of the

C2 dural sleeve with CSF leak or high spinal spread of the

local anesthetic may occur with atlantoaxial joint injection

if the needle is directed a few millimeters medially. Spinal

cord injury and syringomyelia are potential serious compli-

cations if the needle is directed farther medially.”°

Recently, ultrasound-assisted AAJ injection was reported

in an effort to add more safety to the procedure because

ultrasound can identify the relevant soft tissue structures

CHAPTER 41

Cervicogenic Headache 279

Atlanto-occipital joint

Vertebral artery

Lateral Atlanto-

axial joint

C2 dorsal

root ganglion

FIGURE 41-2 Illustration showing the relationship of the atlantoaxial

and atlanto-occipital joints to the vertebral artery. (Reprinted with

permission from Cleveland Clinic)

FIGURE 41-3 Anteroposterior view showing the needle in a tunnel

view inside the lateral part of the lateral atlantoaxial joint. (Reprinted

with permission from Obio Pain and Headache Institute)

FIGURE 41-4 A, The lateral atlantoaxial joint. B, The tip of the

needle and the contrast agent within the lateral atlantoaxial joint.

(Reprinted with permission from Obio Pain and Headache Institute)

280 SECTION VI Chronic Pain Syndromes

FIGURE 41-5 Lateral view showing the tip of the needle and the

contrast agent within the lateral atlantoaxial joint. (Reprinted with

permission from Ohio Pain and Headache Institute)

near the joint (e.g., vertebral artery and C2 dorsal root

ganglion).”!

C2-C3 ZYGAPOPHYSEAL JOINT AND THIRD

OCCIPITAL HEADACHE

The C2-C3 zygapophyseal joint is innervated by the third

occipital nerve, which is the superficial medial branch of

the dorsal ramus of C3.?? Pain stemming from this joint

(named third occipital headache) is seen in 27% of patients

presenting with cervicogenic headache after whiplash in-

jury.’> Tenderness over the C2—C3 joint is the only sugges-

tive physical examination finding and a diagnostic third

occipital nerve block is mandatory to confirm the diagno-

sis. Earlier reports showed that radiofrequency neurotomy

of the third occipital nerve was not effective.?+ However,

with improved radiofrequency technique, complete pain

relief was obtained in 88% of patients with third occipital

headache (Fig. 41-6).?* On the other hand, Barnsley et al.”°

reported the lack of efficacy of intra-articular steroids for

chronic pain stemming from the cervical zygapophyseal

joints.

THIRD OCCIPITAL NERVE NEUROLYSIS

The third occipital nerve is the superficial medial branch of

C3 dorsal ramus. It supplies the C2—C3 zygapophysial joint

while crossing the joint laterally. Also it supplies part of the

semispinalis capitis muscle, and its cutaneous branch supplies

a small area of skin below the occiput.*! Third-occipital

radiofrequency ablation (RFA) was shown to be effective in

the treatment of headache stemming from the C2—C3 joint.

There is usually incomplete lesioning of the third occipital

nerve because of its variable anatomy.” The use of the three

needles technique to accommodate all variations in the

anatomy of the third occipital nerve from just lateral to the

joint line to above or below the joint and creating consecu-

tive lesions no more than one electrode width from adjacent

lesions markedly improve the results?’ (Fig. 41-6).

Numbness in the cutaneous distribution of the third oc-

cipital nerve is very common after RFA, whereas dysesthe-

sia and hypersensitivity (typically at the border of the area

FIGURE 41-6 Lateral view showing three radiofrequency needles

appropriately placed, at the equator of the C2—C3 joint, above and

below the joint line. (Reprinted with permission from Obio Pain and

Headache Institute)

of numbness) occur in up to 50% of cases. These are tem-

porary complications that usually persist for only a few

days to weeks.?3"+ Temporary ataxia has been reported in

most patients as third occipital neurotomy partially dener-

vates the semispinalis capitis muscles with the resultant

interference of the tonic neck reflexes.?3°+

OCCIPITAL NEURALGIA

According to the second edition of the International Classi-

fication of Headache Disorders (CHD), occipital neuralgia

is coded separately under cranial neuralgias.* It is discussed

because of its close relevance to cervicogenic headaches. The

diagnostic criteria include the following:

A. Paroxysmal stabbing pain, with or without persis-

tent ache between paroxysms, in the distribution(s)

of the greater, lesser, and/or third occipital nerves.

B. ‘Tenderness over the affected nerve.

C. Pain eased temporarily by local anesthetic block of

the nerve.

Occipital neuralgia was long thought to be the result of

entrapment of the greater occipital nerve as it emerges

from the trapezius muscle. However, surgical nerve release

gives only short-term relief in about 80% of cases, whereas

nerve excision provides short-term relief in about 70% of

patients.?’°> Occipital neuralgia must be distinguished

from occipital referral of pain from the atlantoaxial or up-

per zygapophyseal joints or from tender trigger points in

neck muscles or their insertions.®

The greater occipital nerve is the terminal branch of the

dorsal ramus of C2 with contribution from C3, whereas

the lesser occipital nerve is a branch of the dorsal ramus of

C3 with contributions from C2. Segmental nerve blocks at

C2 and C3 may be necessary to make the diagnosis in

some cases.?° Cryoneurolysis, radiofrequency ablation, and

more permanent neuroablative approaches such as dorsal

rhizotomy at C1-C3 and partial posterior rhizotomy at

C1-C3 showed variable responses.°°

OCCIPITAL NEUROSTIMULATION

Percutaneous occipital nerve stimulation, unlike other

neuroablative techniques, offers the potential for a mini-

mally invasive, low-risk, and reversible approach to man-

aging occipital neuralgia and some types of intractable

primary headache.**>> PET scan studies showed increased

regional cerebral blood flow in areas involved in central

neuromodulation in chronic migraine patients treated

with occipital nerve electrical stimulation.*° A percutane-

ous trial of peripheral nerve stimulation is performed

using subcutaneous electrodes placed superficial to the

cervical muscular fascia in the suboccipital area. If effec-

tive, a permanent implant may be carried out using the

same electrode lead type or paddle-type surgical lead and

attached to a pulse generator implanted in the infracla-

vicular area, flank, upper buttock, or abdomen (Figs. 41-7

and 41-8).

The most frequent complication of the subcutaneous

techniques of neurostimulation is lead migration necessi-

tating revision the electrodes placement. Various anchor-

ing techniques have been described to improve lead stabil-

ity; however, the problem persists.*”

In one review, lead migration was found to be 33%

and 60% 6 months and | year postimplant, respec-

tively® The use of self-anchoring leads (e.g., tined

leads) looks promising. In a series of 12 patients, only

one patient had a few millimeters of lead migration with

little change in the stimulation pattern, and no loss of

efficacy®? (Fig. 41-9).

The other potential problem with ONS is a painful

stimulation-induced muscle contraction that is related to

the depth of the implanted lead (e.g., deep placement at

the level of the suboccipital muscles). Subcutaneous im-

plant of the ONS lead with ultrasound guidance looks very

FIGURE 41-7 Anteroposterior view showing bilateral occipital

surgical leads. (Reprinted with permission from Obio Pain and Headache

Institute)

CHAPTER 41

Cervicagenic Headache 281

FIGURE 41-8 Anteroposterior view showing right occipital

percutaneous lead. (Reprinted with permission from Obio Pain and

Headache Institute)

FIGURE 41-9 Anteroposterior view showing bilateral occipital

self-anchoring leads. (Reprinted with permission from Obio Pain and

Headache Institute)

attractive, as the lead can be placed under direct vision in

the correct plane superficial to the muscles.?!

C2 NEURALGIA

C2 neuralgia is a distinctive type of occipital neuralgia

caused by lesions affecting the C2 nerve root or dorsal

ganglion, such as neuroma, meningioma, or anomalous

282 SECTION VI Chronic Pain Syndromes

vessels.°*! The C2 root lies posterior to the lateral at-

lantoaxial joint; thus, disorders or inflammation of this

joint may lead to irritation or entrapment of the nerve

root.” C2 neuralgia manifests as intermittent lancinating

occipital pain that is associated with lacrimation, ciliary

injection, and rhinorrhea. Abolition of pain by selective

C2 nerve root block is essential to make an accurate di-

agnosis. Thermocoagulation, decompression, or C2 gan-

glionectomy may be indicated in intractable cases that

respond poorly to pharmacotherapy and other conserva-

tive management.”

CERVICAL MYOFASCIAL PAIN

‘Trigger points in the posterior neck muscles, especially the

trapezius, sternocleidomastoid, and the splenius capitis,

have been proposed as a cause of headache.*?4 According

to the second edition of the International Classification of

Headache Disorders (CHD), headaches causally associ-

ated with cervical myofascial tender spots are coded as

episodic or chronic tension-type headache associated with

pericranial tenderness.®

Moreover, these tender points usually overlie the zyg-

apophyseal joints, so it is difficult to distinguish them

from underlying painful joints.? Needling therapies in the

management of myofascial pain showed no efficacy be-

yond that of placebo.* The use of botulinum toxin is

controversial. It might be effective in the management of

migraine and chronic daily headaches; however, its effi-

cacy in myofascial pain and cervicogenic headaches is still

debatable.****

CERVICAL DISCOGENIC PAIN

C2-C3 provocative discography, but not at the lower lev-

els, can reproduce cervicogenic headache.” Radiofre-

quency lesioning was shown to be effective in obtaining

some pain relief for a few months in one study.*° However,

cervical disc interventions are not commonly performed

because of the potential for esophageal penetration leading

to discitis or vascular injury.

SUMMARY

In summary, cervicogenic headache is one of the most

debatable and challenging areas in headache medicine.

Patients usually benefit the most from a multidisciplinary

approach incorporating physical therapy, pharmacother-

apy, psychotherapy (biofeedback and relaxation therapy),

alternative medicine (acupuncture), and the judicious utili-

zation of interventional pain management modalities.

KEY POINTS

® Cervicogenic headache is referred pain from cervical

structures innervated by the upper three cervical nerves.

@ The diagnostic criteria of cervicogenic headache,

according to the International Headache Society,

include the following: (1) pain referred from a source

in the neck, (2) evidence of a disorder within the cer-

vical spine or soft tissues of the neck as a cause of the

headache, (3) abolition of the headache following a

diagnostic block, and (4) resolution of the pain after

successful treatment of the causative disorder.

e Pain from the C2—C3 zygapophyseal joint is called

third occipital headache. The improved success rate of

neurolysis of the third occipital may be secondary to

improved technique. This includes the use of three

needles to accommodate variations in the anatomy of

the third occipital nerve.

e@ The criteria for occipital neuralgia include pain in the

distribution of the occipital nerves, tenderness over the

affected nerve, and relief from local anesthetic block-

ade of the occipital nerve.

® Occipital nerve stimulation may have central neuro-

modulatory effects in chronic migraine patients. The

most frequent complication of subcutaneous placement

is lead migrations.

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CERVICOGENIC HEADACHE