근골격계 두통과 경추통에 대한 2004년 통증 세미나 - 읽어야

[문형철]

정리해보자.

cervicogenic headache; 

cervical myofascial pain and headache;

and temperomandibular dysfunction

세가지 관점으로 이해!!

panic bird...

ABSTRACT

Musculoskeletal head and neck pain is an extremely common clinical syndrome in outpatient pain practice. Cervical structures are a frequent cause of headache and must be differentiated from primary headache disorders. Convergence of cervical and trigeminal nociceptive pathways in the upper part of the cervical spinal cord is the neurophysiologic basis of this connection. An interdisciplinary pain management approach that addresses psychosocial factors, pharmacologic and interventional pain management and incorporates progressive exercise training is most likely to be effective. This review discusses the comprehensive eval‎uation and management of musculoskeletal head and neck pain with a focus on cervicogenic headache, cervical myofascial pain, and temperomandibular dysfunction. 

- 근골격계 두통과 경추통은 임상현장에서 너무도 흔한 질환.

- 경추구조는 흔히 두통의 원인이 되고, 반드시 두개질환에 의한 두통과 감별해야 

- 경추 척수의 상부에서 경추와 삼차신경 통각전도로의 만남은 이 연결의 신경생리학적 연결성임. 

- 통증치료의 조합은 사회심리학요소, 약물치료적 요소 .... 다양한 접근으로 치료해야 효과적

- 이 논문은 경추성 두통, 근막통증후군, TM 기능부전의 조합으로 토의함. 

 Musculoskeletal head and neck pain syndromes are common in outpatient musculoskeletal pain practice. The underlying neurologic and musculoskeletal causes of pain are variable and can overlap in any one individual. In the management of these patients, it is important to accurately identify and treat these pain generators to optimize patient outcome. It is the purpose of this review to discuss three main categories of musculoskeletal head and neck pain: 

cervicogenic headache; 

cervical myofascial pain and headache;

and temperomandibular dysfunction.

Cervicogenic headache  is defined as a chronic hemicranial pain in which the source of the pain is the cervical structures. The exact pathophysiology and pain source are debated but may include articular, discogenic, ligamentous, neurogenic, and muscular structures. Cervicogenic headache may be the primary cause of headache or may coexist with other primary headache diagnoses.1

Cervical myofascial pain and headache  refers to pain derived from myofascial trigger points that are small, highly sensitive areas in muscle. They are characterized by hypersensitive, palpable taut bands of muscle that are painful to palpation, reproduce the patient’s symptoms, and cause referred pain. Other head and neck symptoms that may be associated with cervical myofascial pain include cervicogenic dizziness, disequilibrium, and tinnitus.2

Temperomandibular dysfunction  (TMD) is a clinical syndrome of pain in the region of the temperomandibular

joint. Etiology is often multifactorial and can be related to local mechanical, inflammatory, or arthritic processes of the joint itself. Alternatively, pain can be referred from cervical structures to the region. Myofascial pain of the masticatory muscles is often involved as well.3

Epidemiology

 The precise incidence of cervicogenic headache is unknown; however, preval‎ence estimates range from 0.4% to 2.5% of the general population to 15% to 20% of patients with chronic headache.1  Myofascial pain has a high preval‎ence among patients with regional pain complaints. The preval‎ence is 30% in a general medical clinic and 85% to 93% in patients presenting to specialty pain management centers.4,5  

Cervical trauma in whiplash patients is followed by neck pain in 62% to 100% of cases and headache in  66% to 87% of patients. Twenty percent to 58% of patients who sustain whiplash or closed head injury may have late-onset symptoms of dizziness, vertigo, and dysequilibrium.6  Cervical osteoarthritis is a common fi nding in the senior population.

Neuroanatomic Basis of Cervical Pain and Headache

 There are good neuroanatomic and neurophysiologic studies in animal models that establish the convergence of cervical sensory and muscle afferent input onto trigeminal subnucleus caudalis nociceptive and non-nociceptive neurons. The trigeminocervical nucleus is a region of the upper cervical spinal cord where sensory nerve fibers in the descending tract of the trigeminal nerve converge with sensory fibers from the upper cervical roots. This convergence of upper cervical and trigeminal nociceptive pathways allows the referral of pain signals from the neck to the trigeminal sensory fields of the face and head.

For example, stimulation of the supraorbital nerve and the infraorbital nerve elicits responses in splenius and trapezius motor neurons.7,8  There are neurons in the spinal cord that respond to electrical stimulation of the trigeminal nerve and of the cervical nerves. In particular, overlap between terminals of the upper three cervical segments and terminals of the trigeminal nerve provide the neuroanatomic basis for cervical myofascial pain causing headache.

Some of the muscles commonly involved include the sternocleidomastoid (supplied by C-1, C-2), the trapezius

(supplied by C-1, C-2), the splenius capitus and the cervicus (supplied by C-2, C-3), and the semispinalis capitus and cervicus (supplied by C-2, C-3).9

 The cervical zygoapophyseal (facet) joints have well-established referral pain patterns that involve the head. Bogduk developed maps of the neuroanatomic referral pattern of C-1/C-2, C-2/C-3, and C-3/C-4, which refer specifically to the head and proximal cervical region.10

 The cervical disks have also been studied and have referral patterns to the head. Several investigators have described referral patterns for cervical discogenic pain.11-13

 In addition, the cervical ligaments may refer pain to the head and proximal axial cervical spine. Hackett and colleagues described pain radiation to the head from the suboccipital, interspinous, supraspinous, and intertransverse ligaments.14

 Finally, one must consider the neuroanatomy of the cervical nerve roots. Either a C-2 or C-3 radiculopathy can result in headache pain and associated weakness in the distribution of the nerve root. The occipital nerve, derived from the C-2/C-3 nerve roots, can become entrapped or injured and may cause lateral cranial pain.15

Pathophysiology of Myofascial Pain

 Current concepts of chronic myofascial pain generally incorporate a complex interplay between peripheral

nociception and central sensitization.16  At the level of the motor endplate, it is hypothesized that there is a pathologic increase in the release of acetylcholine (ACh) by the nerve terminal.17-22  This increased ACh release in turn is proposed to result in sustained depolarization of the post junctional membrane of the muscle fiber and produce sustained

sarcomere shortening and contracture.23

 A consequence of a chronically sustained sarcomere shortening may be increased local energy consumption and reduction of local circulation, a combination that may produce local ischemia and hypoxia.24  This localized muscle ischemia then stimulates the release of neurovasoactive substances that sensitize afferent fibers in muscle and account for

local tenderness.18

 The referred pain resulting from myofascial trigger points stems from central convergence and facilitation. Convergent connections from deep muscle afferent nociceptors to dorsal horn neurons are facilitated, amplified, and referred to adjacent spinal segments. In addition, neuroplastic changes are seen in the dorsal horn and trigeminal nuclei, accounting for central sensitization.25-27

 The sympathetic nervous system presumably plays a role in the commonly described findings of painful skin rolling, hypersensitivity to touch, temperature and blood flow changes, abnormal sweating, reactive hyperemia, dermatographia, and altered pilomotor responses that are associated with myofascial pain.28

Clinical Characteristics

Cervicogenic Headache

 Patients with cervicogenic headache often report the onset of symptoms associated with sustained cervical postures, movement of the neck, or cervical trauma. The pain may be of insidious onset or may occur after a specific local trauma. The pain is often unilateral in the head or face, but occasionally may be bilateral. The pain is moderate to severe, intermittent or constant, and of a deep, aching quality. 

Pain is often triggered by neck movement or digital pressure to the suboccipital, C-2, C-3, or C-4 regions, or over the greater occipital nerve. There is often restricted cervical range of motion and neck stiffness.7  Patients with cervical facet pain, osteoarthritis, and spondylosis may complain of pain and limited range of motion. They often report a sensation of joint crepitus and difficulty looking up, as cervical extension exacerbates symptoms. 

Cervical discogenic pain may present with axial cervical pain, worse with sitting, sneezing, or cough. Cervical radiculopathy will follow the relevant dermatome. On physical examination, patients with cervicognic headache may have restricted range of cervical motion. Pain on palpation of the facet joint capsule, ligaments, or associated musculature that reproduces the patient’ s complaints is a helpful fi nding. Sensory testing of the upper cervical dermatomes as well as

strength testing of the myotomes is important. Diagnostic injection with 1% lidocaine may help to establish the pain generator. This may be done with a selective nerve-root block, intraarticular facet injection, or injection of the ligament.29

Myofascial Pain

 Patients with myofascial pain report a deep regional ache that is often accompanied by a sensation of pulling or tightness. The intensity can vary from mild to severe. Cervical myofascial pain may be associated with autonomic dysfunction, abnormal sweating, lacrimation, dermal fl ushing, and vasomotor and temperature changes. Neuro-otologic symptoms may include imbalance, dizziness, or tinnitus.

Functional complaints include impaired muscle coordination, stiffness, muscle fatigue, and weakness. On physical examination, the patient may demonstrate abnormal cervical posture, biomechanics, joint function, muscle strength, and imbalances. The physician should be able to identify active trigger points in one or several muscles. Four of the most common muscles that manifest trigger points in patients with headache include the temporalis, upper trapezius, splenius capitus, and sternocleidomastoid (Fig 1).2

 The trigger point should be identifi ed by gentle palpation across the direction of the muscle fibers. The examiner appreciates a “ rope-like”  nodularity to the taut band of muscle. Palpation of the area is painful and reproduces the patient’ s local and referred pain pattern.

Temperomandibular Dysfunction

 Patients with TMD complain of pain with mastication in the region of the angle of the jaw. This is often accompanied by a clicking sensation upon opening and closing of the mouth. There is often spreading of pain into the side of the face and to the ear.

On physical examination there may be limited opening of the mouth, associated with tenderness to palpation along the joint line. Muscle tenderness and trigger points may be found in the muscles of mastication and face, including the masseter, pterygoid, temporalis, and buccinator. Patients often have pain and dysfunction in the cervical spine as well. Dental eval‎uation may reveal occlusal malalignment, and abnormal wear pattern of the dentition reflecting chronic clenching and bruxism.30,31

Differential Diagnosis

 The differential diagnosis of musculoskeletal head and neck pain includes:

1. Other headache types: chronic tension-type headaches with pericranial tenderness.

2. Migraine, cluster, and hemicrania continua.

3. Cervical synovial facet joint pain.

4. Occipital neuralgia.

5. Head pain associated with temporomandibular disorders.

6. Infl ammatory disorders: polymyositis; polymyalgia rheumatica; temporal arteritis; and rheumatoid arthritis.

7. Neurologic disorders: radiculopathy and entrapment neuropathy.

8. Discogenic disorders: degenerative disk disease; annular tears; protrusion; and herniation.

9. Mechanical stresses: postural dysfunction and poor ergonomic worksite.

10. Ligamentous sprain.

Diagnostic Testing

 Laboratory testing may include complete blood

count (CBC) with erthyrocyte sedimentation rate

(ESR) if there is a suspicion of infl ammatory joint

disorders or polymyalgia rheumatica/temporal arteritis.

Chemistry panel and thyroid testing may be

indicated to search for systemic diseases that may

adversely affect muscle (ie, thyroid or parathyroid

disorders, and primary muscle disease).

Diagnostic imaging, such as radiography, single

photon emission computed tomography (SPECT)

bone scan, computed tomography (CT)/CT myelography,

and magnetic resonance imaging (MRI), cannot

provide the diagnosis in isolation, but can lend  support to the clinical impression.7,32  Imaging is important

to exclude lesions that may require surgery,

such as Arnold-Chiari malformation, herniated intervertebral

disk, central or foraminal stenosis, vertebral

fracture, and spinal tumors.7,33  If structural or vascular

lesions of the brain are suspected clinically, then

brain imaging should be obtained.

Diagnostic anesthetic blockade is a valuable tool

to confi rm diagnostic impressions and guide further

corticosteroid, neuromodulatory, and neuroablative

pain management procedures. Flouroscopically

guided diagnostic anesthetic blockade of C-2 and

C-3 spinal nerves, third occipital nerve (dorsal ramus

C-3), medial branches supplying the zygapophyseal

joints, intraarticular z-joint injections, and greater

and lesser occipital nerves may be undertaken to

assure accurate and specifi c localization of the pain

source.29  Cervical discography can be performed to

identify discogenic pain; however, the interpretation

and clinical relevance remain debated.12,13  Diagnostic

trigger-point injections with lidocaine may have

therapeutic value as well.

Treatment of Musculoskeletal Head and Neck Pain

In general, the successful treatment of musculoskeletal

head and neck pain involves a multifaceted

approach. Often, a combination of pharmacologic,

nonpharmacologic, interventional, manipulative,

and behavioral medicine techniques are necessary.

The clinician must meticulously eval‎uate, diagnose,

and treat the pain generators. In addition, sleep disturbance,

mood disorders, central sensitization, and

deconditioning should be addressed so that the patient

will ultimately be restored to optimal function

and independence.

Pharmacologic Treatment

Pharmacologic treatments for cervicogenic headache,

cervical myofascial pain, and TMD are similar.

The medications reviewed here have not been approved

specifically by the U.S. Food and Drug Administration

(FDA) for these indications. Few randomized,

controlled trials exist. The medications

discussed in what follows are presented with currently

available medical evidence in combination

with the anectodal clinical experience of physicians

who treat these conditions.

Nonsteroidal anti-inflammatory drugs (NSAIDs). The

NSAIDs are indicated to treat underlying synovial

inflammation from osteoarthritis or neurogenic inflammation

secondary to cervical radiculopathy.

There is minimal literature supporting the use of

NSAIDs for the treatment of chronic muscle pain,

myofascial pain, or TMD.34,35

Tramadol. Tramadol is a combination of a weak

mu-opioid agonist and serves as an inhibitor or for

reuptake of serotonin and norepinephrine in the

dorsal horn. There are no published controlled trials

of tramadol as a treatment for myofascial pain; however,

several studies support its efficacy in the management

of fibromyalgia, chronic back pain, and

osteoarthritis, all of which are commonly associated

with musculoskeletal head and neck pain.36-39

Antidepressants. Tricyclic antidepressants (eg, amitriptylene)

have been found effective in the treatment

of chronic tension-type headache, fibromyalgia,

acute low back pain, and intractable syndromes

with muscle spasm.40 Selective serotonin reuptake

inhibitors have not been studied specifically for myofascial

pain, although efficacy has been documented

in fibromyalgia for improving pain, sleep, and providing

a global sense of well-being.41

Alpha-2-adrenergic agonists. The two major alpha-2-

adrenergic agonists available for clinical use are

clonidine and tizanidine. Tizanidine acts centrally at

the level of the spinal cord to inhibit spinal polysynaptic

pathways and to reduce the release of aspartate,

glutamate, and substance P.42 In addition, tizanidine

has supraspinal effects that increase nociceptive

thresholds and inhibit the responses of spinal neurons.

43 In one study of tizanidine, a mixed population

of patients with myofascial pain syndrome or

fibromyalgia were observed: tizanidine treatment reduced

pain.44

Anticonvulsants. There have been no controlled trials

focusing on anticonvulsants in the treatment of

myofascial pain, TMD, or cervicogenic headache.

One open-labeled study of gabapentin, used in the

treatment of chronic daily headache, found possible

efficacy.45 Administration of gabapentin and topiramate

may be considered in the treatment of coexistent

migraine or neuropathic pain.

Botulinum toxin. Botulinum toxin type A is emerging

as a promising (but expensive) new agent used to

treat chronic myofascial pain syndromes and chronic

headaches. In two recent studies of myofascial pain,

botulinum toxin injections provided greater relief of

pain symptoms compared with placebo.46,47 In studies

of migraine headache, chronic daily headache

(15 days of headache per month), tension-type

headache, and post-whiplash headache, patients reported

decreased pain after treatment with botulinum

toxin type A. A more recently available preparation,

botulinum toxin type B, has also been shown

to provide relief for patients with post-whiplash

headache.47 There may be a peripheral and central

mechanism that explains the apparent efficacy of

botulinum toxin in the treatment of chronic

pain.48,49

Nonpharmacologic Treatment

Postural, mechanical, and ergonomic modifications. 

Cervical muscle and skeletal dysfunction may be caused and perpetuated by abnormal postures, especially those related to poor ergonomics at home and in the workplace. Correction of awkward postures and ergonomic management is often an effective component of treatment.50,51

Stress reduction. 

Stress reduction techniques, including cognitive-behavioral programs, meditation, progressive relaxation training, and biofeedback, should be incorporated into chronic pain rehabilitation programs.52

Acupuncture. 

A growing body of evidence supports the efficacy of acupuncture in the treatment of myofascial pain, neck pain, and headache. The limited amount of high-quality data suggest that traditional   acupuncture is effective for relieving pain, improving global ratings, and reducing morning stiffness in chronic muscle pain.53  Birch and Jamison found relevant

acupuncture (over points relevant to myofascial neck pain) to be superior to NSAID treatment and irrelevant acupuncture (superfi cial needling over points not related to neck pain) in a group of 46 patients with chronic myofascial pain.54  Areas that need to be addressed in future randomized trials include the duration of benefi t of acupuncture, the optimal acupuncture techniques, and the value of booster treatments.

Exercise . 

Stretching forms the basis of exercise treatment

of myofascial pain. This treatment addresses

muscle tightness and shortening as well as restricted

motion associated with myofascial pain and osteoarthritis.

Patients should be encouraged to remain

active, but perform daily activities in a gentle, lightly

loaded manner. A graded stabilization and strengthening

program should be undertaken to maximize

the functional outcome.55,56  Aerobic exercise should

be included in the overall musculoskeletal and cardiovascular

fi tness program to prevent recurrence. In

TMD, a combination of specifi c active and passive

jaw movement exercises, correction of body posture,

and relaxation techniques are helpful.57

Nutrition/diet . There is no specifi c diet that is recommended

for chronic pain. Studies suggest that

omega-3 fatty acids have an anti-infl ammatory effect

equivalent to NSAIDs and thus may have some theoretical

value in patients with cervical osteoarthritis.

58  Patients with TMD benefi t from a softer mechanical

diet and avoiding repetitive activity such as

gum chewing.59

Manipulative and physical therapy . An experienced

and skilled physical therapist, osteopath, or chiropractor

often can reduce symptoms with manual

therapy such as mobilization, manipulation, and

myofascial release techniques. These may be directed

to the cervical spine, jaw, and surrounding soft tissue

structures. Although patients often report improvement

with a “ hands-on”  approach, there are few

well-done trials that support these anecdotal reports.

More research is needed in this area. Most importantly,

manual therapies should be combined with a

progressive conditioning and stabilization exercise

program.60-62

Therapeutic injections . Trigger point injection: Trigger

point injections are useful for areas of recalcitrant

myofascial pain. The patient should be informed that

this treatment has a limited role in the long-term

management of myofascial pain, but will reduce the

pain and facilitate an active exercise and self-management

program. Three consecutive injections are

often recommended in chronic myofascial pain, with

reassessment after the third injection to eval‎uate the

effi cacy of the injections and to determine whether

further injections are needed. The effectiveness of

needling depends on the needle-eliciting local twitch

responses.63

 Cervical zygoapophyseal (facet) joint injection

and radiofrequency neurotomy: Therapeutic intraarticular

z-joint injections can help alleviate pain related

to arthritic or traumatically injured joints. During

radiofrequency neurotomy, the medial branch of

the dorsal ramus of the spinal nerve, which supplies

the z-joint and midline structures, is lesioned. A

therapeutic neurotomy is considered only if diagnostic

anesthetic injection with control blocks is positive.

64  There is limited evidence that radiofrequency

denervation offers short-term relief for chronic neck

pain of cervicobrachial origin.65

 Selective nerve root injection: In the presence of

cervical radiculopathy, a corticosteroid-selective

nerve-root injection may be performed to reduce

radicular pain.66

 Ligament injection: Chronically injured, strained,

and painful ligaments of the cervical spine may respond

to local injection. Some clinicians report success

with corticosteroid ligament injections. Ligament

injection of proliferant solutions such as

hypertonic dextrose (known as prolotherapy or regenerative

injection therapy), presumably decreases

pain by improving ligament strength and promoting

healing; however, there have been no studies that

specifi cally address cervicogenic headache, TMD, or

cervical myofascial pain.67

Conclusions

 The management of chronic musculoskeletal head

and neck pain represents a common, yet formidable

challenge to the pain practitioner. The dense network

of connective tissue structures, in combination with

overlapping jaw and primary headache disorders,

makes the differential diagnosis complex. Often, an

interdisciplinary approach guided by a compassionate

provider can be successful. Further research to

guide diagnosis and treatment in this area is clearly

needed.

References

1. Haldeman S, Dagenis S: Cervicogenic headaches: A

critical review. Spine J 1:31-46, 2001

2. Borg-Stein J: Cervical myofascial pain and headache.

Curr Pain Headache Rep 6:324-330, 2002

3. Visscher CM, Lobbesoo F, et al: Preval‎ence of cervi- 

[정혜]

감사합니다

[참마음]

감사합니다~