Cervical Radicular Pain and Radiculopathy

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Written by: Dr Jeremy Steinberg – created: 20 August 2020; last modified: 23 April 2022

This page is probably complete!
It is awaiting peer review
Right C6-7 disc protrusion MRI axial.jpg
MRI T2 axial image showing right paramedian C6/7 disc protrusion compressing the right C7 nerve root
Cervical Radicular Pain and Radiculopathy
Definition
  • Cervical radicular pain: Pain perceived as arising in a limb or the trunk wall caused by ectopic activation of nociceptive afferent fibers in a spinal nerve or its roots or other neuropathic mechanisms.
  • Cervical Radiculopathy: Objective loss of sensory and/or motor function as a result of conduction block in axons of a spinal nerve or its roots.
Epidemiology Peak incidence 50-54 years old
Causes "Hard" and "Soft" processes. C6 and C7 nerve roots most commonly involved.
Pathophysiology
  • Radiculopathy: Nerve root compression
  • Radicular pain: Nerve root inflammation or dorsal ganglion compression
Risk Factors Diving, coughing, heavy lifting
Clinical Features Pain in dynatomal distribution; numbness in dermatomal distribution, weakness in myotomal distribution, hyporeflexia; positive special tests.
Tests MRI cervical spine
Treatment Conservative, physiotherapy, analegisa, epidural corticosteroid, decompression and fusion.
Prognosis Generally good

Cervical radicular pain is pain perceived as arising in a limb or the trunk wall caused by ectopic activation of nociceptive afferent fibres in a spinal nerve or its roots or other neuropathic mechanisms. Cervical radiculopathy is the objective loss of function in some combination of sensory loss, motor loss, or impaired reflexes, in a segmental distribution. Pain is not a component of radiculopathy, and so it can be helpful to distinguish it from cervical radicular pain.[1] (See also Cervical Spine Pain Definitions and Radicular Pain and Radiculopathy to be clear on taxonomy)

Pathophysiology

Less is known about the causes and mechanisms of cervical radicular pain compared to lumbar radicular pain.

Mechanism of Pain and Radiculopathy

See also: Radicular Pain and Radiculopathy, Cervical Discs

The literature often uses the term cervical radiculopathy, but radiculopathy and radicular pain are not synonymous.

Radiculopathy arises from either direct compression of a cervical spinal nerve or root, or by ischaemia from vascular injury to their blood supply. There is a conduction block along the affected axons which results in sensory or motor loss. Compression of axons, including those of the lumbar nerve roots, does not cause activity in nociceptive afferent fibres. Meanwhile, compression of a dorsal root ganglion does cause pain through activation of Aβ, Aδ, and C fibres. The causes of cervical radicular pain cannot therefore be attributed to the same causes as those of radiculopathy.

It is thought that inflammation of the cervical nerve roots is the underlying mechanism through which radicular pain occurs secondary to disc herniation. Pro-inflammatory molecules have been found in disc material, however unlike with lumbar radicular pain it hasn't been explicitly shown that cervical radicular pain is inflammatory in origin.

Meanwhile, inflammation cannot be the cause of pain in other causes of radicular pain when due to tumours, cysts, and osteophytes. In these conditions it must be through dorsal root ganglion compression that pain occurs, as these conditions are non-inflammatory in nature.[1]

"Hard" and "Soft" Processes

Soft protrusion are lesions in which the disc material, ostensibly the nucleus pulposus, is extruded into the vertebral canal. The extrusion can be medial or lateral. With medial protrusions the effect is primarily on the spinal cord and myelopathy may occur, while pain is uncommon or inconspicuous. With lateral protrusions there is impingement on the spinal nerve and its roots in the intervertebral foramen, and this is regularly associated with pain.

In cervical spondylosis there may be narrowing of the cervical vertebral canal and the cervical intervertebral foramina due to

  • Osteophytes of the zygapophysial joints or the uncinate process
  • Hard protrusions of the intervertebral discs. This consists of osteophytes from the margins of the vertebral bodies or fibrocartilaginous or osseous bars that protrude transversely across the back of the disc - i.e. "hard disc"

Aetiology

Possible causes of cervical radiculopathy (different to radicular pain)[1]
  • Disc
    • Protrusion
    • Herniation
    • Osteophytes
  • Facet joint
    • Osteophytes
    • Ganglion
    • Tumor
    • Rheumatoid arthritis
    • Gout
    • Ankylosing spondylitis
    • Fracture
  • Vertebral body
    • Tumor
    • Paget’s disease
    • Fracture
    • Osteomyelitis
    • Hydatid
    • Hyperparathyroidism
  • Meninges
    • Cysts
    • Meningioma
    • Dermoid cyst
    • Epidermoid cyst
    • Epidural abscess
    • Epidural hematoma
  • Blood vessels
    • Angioma
    • Arteritis, vasculitis with nerve root infarction
  • Nerve sheath
    • Neurofibroma
    • Schwannoma
  • Nerve
    • Neuroblastoma
    • Ganglioneuroma
    • Nerve root avulsion
  • Infectious or granulomatous
    • Herpes zoster
    • Tuberculosis
    • Syphilis
    • Brucelosis
    • CMV
    • Histiocytosis
    • Sarcoid
    • Lyme disease
  • Infiltration
    • Lymphoma
    • Carcinomatous meningitis
  • Acute demyelination
    • Early Guillain-Barré syndrome
  • Diabetes Mellitus

The most common cause of cervical radiculopathy is intervertebral disc herniation. It is not completely clear why some people with disc herniation develop radiculopathy while others don't but it appears that an inflammatory response can lead to neurophysiologic dysfunction.

The second most common cause is degenerative change. This includes ligamentous hypertrophy, hyperostosis, disc degeneration, facet joint hypertrophy, and uncovertebral joint hypertrophy. Hypertrophy of the latter two structures can lead to foraminal stenosis and nerve root compression. Osteophytosis can also be involved in compression.

Other causes are less common such as facet joint cysts, trauma, haematomas, fibroproliferation, and various tumours.[2]

Nondegenerative causes or cervical radiculopathy or polyradiculopathy includes diabetes mellitus, infection (especially herpes zoster) nerve root infarction, root avulsion, tumour or granulomatous tissue infiltration, and demyelination.

Epidemiology

The most commonly affected nerve roots are C6 and C7. The pre-test probability of C7 is 54%. C4 and C8 are rare. C5 is variable.

The incidence estimated as 5.5 per 100,000 population per year. The peak incidence is 50-54 years old.

Trauma is the alleged cause in fewer than 20% of cases.

Risk Factors associated with cervical disc prolapse are diving, coughing and heavy lifting. There is a trend with golfing, smoking, manual labour, driving, and using vibrating tools. There is no association with psychosocial factors.

Clinical Features

Radicular pain is strongly associated with neurological signs, such as numbness, weakness and hyporeflexia. Neck pain alone, or pain in the shoulder girdle or proximal regions of the upper arm is more likely to be somatic referred pain (see Acute Neck Pain and Chronic Neck Pain)

Summary of clinical symptoms in cervical radiculopathy.[3]
Symptom Proportion (%)
Arm pain 97–99
Sensory deficit 85–91
Reflex deficit 71–84
Neck pain 56–80
Motor deficit 64–70
Periscapular pain 37–52
Anterior chest pain 18
Headaches 10

Pain Pattern

Figure 1. Dynatomal pain patterns in cervical radicular pain.[4]
Figure 2. Referred scapula pain. (a)C5 and C8 cutaneous nerves traverse up and down the spine of the scapula, respectively, whereas the courses of C6 and C7 cutaneous nerves are not found.
(b) The site of radicular pain involving the C6 root overlaps with that of the C5 root, and also involves the posterior deltoid.[5]

The pattern of cervical radicular pain is not dermatomal, but rather dynatomal (figure 1). The pain is typically in the neck (89% in one surgical series[6]) and arm , but can also be felt in the head, shoulder girdle, and the anterior chest.[6]

  • With dorsal root pain the quality is described as lightning or electric-shocks, with radiation along the entire length of the upper arm. Proximally the pain is diffuse, but peripherally it is distinct where it typically involves the hand.
  • With ventral root pain the pain is never felt distally. It is deep and boring, and perceived over the scapula and/or dorsal arm.

Proximal pain in the scapula and shoulder girdle usually precedes pain in the arm and/or fingers (figure 2). This is analogous to the common finding of buttock pain with lumbar radicular syndrome. The reason it is not dermatomal is likely due to the pain not being restricted to cutaneous fibres, but there is also a deeper pain arising from the muscles and joints.

The segmental innervation of the skin (dermatomes) is different to that of the deeper tissues. The muscles of the shoulder girdle are supplied by C6 and C7, very different to their dermatomes. See C6 and C7 columns in the complete myotome chart, and note how for example latissimus dorsi receives innervation from C6-C8. As such, the segmental innervation of the muscles is more closely related to the radicular pain patterns than the segmental innervation of the skin (dermatomes). Dermatomes are more helpful for patterns of sensory loss in radiculopathy.[1][5]

The site of scapula pain may be a helpful data point in determining the affected level in cervical radicular pain (table 1). Mizutamari et al suspect that scapula pain occurs through the medial branches of the dorsal rami of the cervical nerves. They found that there was no cutaneous course of C6 and C7 and that these patients complained of deep scapula pain only. This is compared to patients with C5 and C8 lesions having both superficial and deep pain.[5]

Table 1. Mizutamari et al found the following pain referral pattern:
Nerve root Shoulder Girdle Region Deep or superficial
C5 Suprascapular region Superficial and deep pain
C6 Suprascapular to posterior deltoid region Deep pain
C7 Interscapular region Deep pain
C8 Interscapular and scapular regions Superficial and deep pain

Slipman and colleagues coined the term dynatomal pain to describe radicular pain patterns. They purposefully stimulated the nerve roots of patients with cervical radicular syndromes and diligently recorded the pain patterns (figure 1). They found that while there was overlap with dermatomes, symptoms frequently were perceived outside of dermatomal regions.

  • Pain in the lateral or posterior upper arm is most likely to be C7 radiculopathy, although C6 can also present with lateral limb posterior arm pain.
  • Pain or paraesthesia in lateral forearm is typically C6 or C7 (most likely C7), NOT C5 C8.
  • Pain or paraesthesia in medial or posterior forearm C7 or C8 (most likely C7), NOT C5 C6
  • Forearm pain or paraesthesia is most likely C7[4]

Neurological Examination

Figure 3. Sensory impairment in C6 and C7 radiculopathy. The asterix indicates the only area where there is a statistical difference, with impaired in the distal radial aspect of the dorsal forearm more common in C6 than C7 radiculopathy. Based off data from Rainville et al. [7]

Patients with cervical radicular pain often have a concomitant radiculopathy and so warrant a neurological examination. The neurological examination is used to determine the severity of the condition, identify signs of myelopathy, and potentially determine the location of the lesion.

Cervical radiculopathy is typically characterised by negative objective signs: sensory loss, motor loss, or impaired reflexes, which occur in a segmental distribution. It may be possible to determine the affected level based on the neurological examination.[8]

Sensory loss in surgically proven disc prolapse was present in 25% in one study (method of exam not defined)[8], and and 85% in another (pin prick).[6] The sensory loss occurs in the upper limbs, and classically has been described to be dermatomal in distribution.[1] The likelihood ratios can be calculated from Yoss's study: thumb sensory loss has a +LR of 8.5 for C6, middle finger loss is not significant for C7, and little finger sensory loss has a +LR of 41.4 for C8.[8] However a more recent study with better methodology found that C6 and C7 could not be differentiated based on dermatomes alone (figure 3).[7]

The reliability of sensory loss has a Kappa score of 0.45-0.64.

If a patient only has sensory signs then the weight of the evidence suggests that the segmental level can't be determined with any level of accuracy, perhaps with the exception of sensory loss of the little finger for C8. (See also Dermatomes).

Paraesthesias are present with or without pain in 90% of surgically proven radiculopathy due to disc prolapse.[8] None of the patterns of paraesthesias are pathognomonic. 45% of patients are unable to localise the paraesthesias with diffuse and/or non-dermatomal symptoms.[6] Some of these patients may have combined C6 and C7 radiculopathy further complicating matters.

The classic distribution of paraesthesias is as follows: [8]

  • C5: Generally no hand paraesthesias, however the lack of hand paraesthesias can also occur with C6 and C7.
  • C6: Thumb or index finger is C6. However C7 is also possible.
  • C7: Middle finger is generally C7 with or without the thumb, index, and middle fingers. Index finger alone is generally C7.
  • C8: Ring, little finger +/- the middle finger is generally C8. However C7 is also possible.

Weakness can be subjective or objective and occurs in a myotomal pattern. In patients with surgically proven radiculopathy, in one study subjective weakness was present in 34% and objective weakness in 75%,[8] while another study found objective weakness in 68%.[6]

  • Weakness of elbow flexion is suggestive of C5 radiculopathy with a +LR of 5.3[8]
  • Weakness of the wrist extension and/or elbow flexion is suggestive of C6[8] radiculopathy with a +LR of 2.3
  • Weakness of the elbow extension is suggestive of C7 radiculopathy with a positive LR of 4.0[8]
  • Weakness of finger flexion is suggestive of C8 radiculopathy with a positive LR of 3.8[8]

The myotomal pattern of innervation is different to the dermatomal pattern of innervation. Because of the myotomes also supply proximal shoulder girdle muscles this can be used to differentiate between a proximal lesion (spinal nerve or root) versus a lesion in a peripheral nerve (radial, ulnar, median, etc). A peripheral nerve lesion is not going to cause proximal motor weakness. So patients with cervical motor radiculopathy may have scapular winging in addition to distal weakness.

Hyporeflexia can occur with lateral protrusions, while hyperreflexia can occur with medial protrusions. Reflex loss is present in approximately three quarters of patients with surgically proven radiculopathy.[8] Reflex loss can aid in distinguishing the spinal level. (See also Reflex Testing).

  • A loss of biceps or brachioradialis reflex has a +LR of 14.2 for C6 radiculopathy (but can also occur in C5),
  • A loss of triceps reflex has a +LR of 3 for a C7 radiculopathy (but can also occur in C8).[9]

Myelopathy: It is important to examine for and document the presence or absence of any long tract signs suggesting cervical myelopathy, including gait, Hoffman's, Babinski, clonus, hyperreflexia, and spasticity. Enquiry should also be made as to bowel and bladder functoin.

Special Tests

Spurling's test (compression test) is a special test used to reproduce the patients radicular pain (see video). Cervical extension tends to cause posterior disc bulging, while lateral flexion and rotation tends to cause narrowing of the ipsilateral neural foramina.

It has good reliability with Kappa score of 0.4-0.77, and good validity if a positive test is taken as the reproduction of the arm pain not only the neck pain. It is highly specific but has poor sensitivity and so it isn't useful as a screening test.[10] Many patients with significant and symptomatic radiological changes do not have a positive compression test.

Shoulder abduction relief test is performed by asking the patient to lift their symptomatic arm above their head and rest the head on the top of their head. The test is positive with the reduction or elimination of radicular symptoms. Similar to Spurling's test it has good specificity but limited sensitivity.[11]

Sensitivity and specificity of special tests in cervical radiculopathy.[3]
Variable Sensitivity (%) Specificity (%)
Spurling 30–50 74–93
Shoulder abduction 17–78 75–92
Valsalva 22 94
Distraction 44 90–97
Upper limb tension test 72–97 11–33

Red Flags

Serious causes of radiculopathy are rare.

Red Flags
  • Spinal infection – fever – history of risk factor (body penetration).
  • Metastatic disease – history of cancer
  • Primary tumours of spinal nerves – may present with radicular pain, but normally profound sensory loss
  • Arteritis – fever and malaise (patient sicker than disc protrusion)
  • Sarcoidosis – profound sensory and motor loss
  • Apical tumours of the lung (Pancoast tumour) – involvement of C8 or T1 spinal nerves
  • Intracranial tumour – no valid alerting features if presenting features restricted to neck and upper limb – rapid progression of symptoms only feature


Differential Diagnosis

Differential Diagnosis of Neuropathic Arm Pain

The history and neurological examination can help to differentiate between radiculopathy, myelopathy, brachial plexopathy, and peripheral nerve lesions.

Brachial Plexus Lesions

Neuralgic Amyotrophy: In acute brachial-plexus neuritis, also known as Parsonage-Turner syndrome, or neuralgic amyotrophy, there is simultaneous weakness of muscles from two or more adjacent spinal segments and from two or more peripheral nerves. They typically affect either the upper plexus (C5 and C6) as a group which causes weakness of the shoulder and upper arm but spares the hand, or the lower plexus (C7 to T1) as a group which causes weakness of the hand but spares the shoulder and the upper arm.

There is an acute onset of pain in the neck, shoulder, and arm, followed by marked anaesthesia and weakness of the arm within a few days to week as the pain eases. In cervical radiculopathy usually the pain and neurologic deficits occur simultaneously.

Pancoast Syndrome: There is paraesthesias and weakness involving the intrinsic hand muscles, along with ipsilateral pstosis, miosis, and anhidrosis (i.e. Horner's syndrome)

Stinger: In sportspeople, traction injury to the upper trunk of the brachial plexus. Need to exclude C6 radiculopathy

Peripheral Nerve Lesions

In peripheral nerve lesions there is weakness of two or more muscles from a single peripheral nerve (which may belong to different spinal segments) and sparing of muscles from other nerves. The pattern of weakness varies depending on the location of injury. Finding hyporeflexia argues against a peripheral neuropathy. Importantly, it argues against both median and ulnar neuropathies as a cause for their symptoms because the median and ulnar nerves lack reflexes.

Nerve conduction studies can also help to discriminate between radiculopathy and peripheral nerve lesions. In radiculopathy they are normal, in peripheral neuropathy they are abnormal

Radial nerve injury: A complete radial nerve injury causes weakness of the brachioradialis muscle, elbow extension, wrist extension, and finger extension (C5-C8). However a radial nerve lesion at the elbow after the branch to brachioradialis will only weaken the wrist and finger extensors. In severe peripheral nerve lesions there may be a classic appearance in the position of the hand such as the wrist drop of radial neuropathy and claw-hand of ulnar neuropathy.

There is sparing of the brachioradialis and triceps reflexes because the nerve branches to these muscles diverge from the main trunk proximally in the axilla, and most radial nerve injuries occur distal to this point.[9]

Carpal tunnel syndrome: Carpal tunnel syndrome can mimic C6 radiculopathy. In C6 radiculopathy there may be pain or numbness that runs from the neck to the radial side of the arm, forearm, and dorsal web space of the hand between the 1st and 2nd digits. There may be weakness of the wrist extensors and biceps, and hyporeflexia of the biceps or brachioradialis. In Carpal tunnel syndrome there may be pain and numbness affecting the radial three and a half digits, along with thenar muscle atrophy, positive Tinel's, positive Phalens, or positive Durkan's tests.

Figure 4. Motor actions of the adductor pollicis (A), abductor pollicis brevis (B), lumbricals (C), flexor pollicis brevis (D), and opponens pollicis (E). Metacarpophalangeal joints are indicated by yellow circles in A and B. Copyrighted image.[12]

Cubital tunnel syndrome: C8-T1 radiculopathies can be differentiated from cubital tunnel syndrome through detailed examination of the motor function of the hand (figure 4). All but five intrinsic hand muscles are innervated by the ulnar nerve. The five remaining muscles are innervated by C8-T1 via the median nerve. The mnemonic AbOF can be used to remember which muscles are above the law in that they aren't innervated by the ulnar nerve: the abductor (Ab) and flexor (F) pollicis brevis, opponens pollicis (O), and lateral lumbricals (Law). In cubital tunnel syndrome the motor function of these muscles are intact, while in C8-T1 radiculopathies they may be weak. In cubital tunnel syndrome there should also only be sensory change to the lateral hand, not the forearm.[12]

Posterior interosseous nerve entrapment: This lesion can mimic C7 radiculopathy. In PIN entrapment there is weakness of triceps, wrist flexors, and flexor extensors. However there is no loss of sensation and triceps and wrist flexors have normal power.

Myelopathy

Myelopathy is a rare condition that can occur with a central disc protrusion. Symptoms and signs of myelopathy occur in the upper limbs, trunk, and lower limbs. The examination is used to determine whether long tract signs are present such as hyperreflexia, spasticity, and a positive Hoffman's sign. Patients may present with signs only in the upper limbs. There is the absence of lower motor neurone signs

Somatic Lesions

C5 radiculopathy can mimic shoulder pathology such as a rotator cuff tear where both can result in weak shoulder abduction. However C5 radiculopathy shouldn't cause pain during passive motion and impingement tests should be negative and reflexes may be impaired.

Investigations

Imaging

Plain films are routinely unhelpful diagnostically as a sole diagnostic test.

Previously myelography and CT were used but this has been replaced by MRI due to its technical superiority and better safety profile. MRI is slightly inferior for detection of bony impingement of nerve roots but this can be aided by also doing plain radiographs. Also newer MRI small slice sequence techniques can be used which are much better at showing bone.

Electrodiagnostic Studies

These are only potentially helpful if clinically a peripheral neuropathy is suspected.

Prognosis

The prognosis is generally good, although not as good as neck pain alone. One study found that recurrences were common at 31.7%, and 90.5% had minimal or no pain at a mean follow up of 5.9 years. A systematic review found that most patients improve within six months. Complete improvement took two to three years and was achieved by 83% of people. This recovery has radiographic correlation as half of cervical disc herniations decrease within the first six months, and 75% decrease by more than 50% within two years. Risk factors for poor outcome is an ongoing worker's compensation claim.[13]

Studies using CT and MRI over 1-30 months show cervical disc protrusions decrease as a rule

Treatment

Conservative

Conservative therapy includes measures such as oral medication, physiotherapy, traction, collar, bed rest, exercise, and TENS. Much of the comparative research on conservative therapy is quite old (?external validity), all of it showing no benefit for any particular conservative passive intervention, and that conservative therapy is effectively equal to sham therapy. A 1966 study found no difference between traction, sham traction, collar, heat, and placebo tablets.[14] A 1970 study found no difference between exercise, traction, and no treatment. A 1990 study found no clinically important difference between traction and placebo traction.[15] A 2009 study found that a wait and see approach was inferior to both a semi-hard collar with rest and physiotherapy with home exercises.[16]

Generally patients with cervical radicular pain should be offered some form of therapy, because no treatment results in a greater proportion of patients feeling that they haven't improved. However no specific therapy can be recommended as being superior to one another.

Medication can be considered such as TCAs, SNRIs, and gabapentinoids but there is limited evidence. Pregabalin is ineffective in lumbar radicular pain.[17] There is no role for oral steroids.

Injections

This refers to transforaminal or interlaminar epidural corticosteroid injections.

Some clinicians have a preference for an interlaminar approach due to possible less risk of a black swan catastrophic event that can occur with the transforaminal approach. The interlaminar approach is typically done at at C7/T1 level regardless of the site of the disc protrusion because the epidural space is largest at this level. In some cases it can be done at C6/7 but no more cranial than that. If there is minimal epidural space seen on MRI then the procedure should not be attempted.

The Pain Physician Epidural Guidelines found that there is level I evidence for cervical interlaminar epidural injections with strong recommendation for long-term effectiveness.[18]

Surgery

Surgery includes discectomy or foraminal decompression. There are two main approaches: anterior cervical discectomy and fusion and posterior laminoforaminotomy. Artificial disc replacement (cervical disc arthroplasty) is an emerging treatment that is currently controversial.[3]

Surgical approaches for cervical radiculopathy. Modified from Kang et al.[3]
Approach Application Advantages Disadvantages
ACDF Lateral and midline disc herniation and osteophytes Direct removal of anterior pathology; bone graft or cages; maintain cervical disc height and prevent kyphosis, less manipulation of the spinal cord and nerve roots. Pseudarthrosis; hardware failure; adjacent segment disease; small risk of damage to recurrent laryngeal nerve, carotid artery, trachea, oesophagus.
PCF Single lateral disc herniation Minimal invasiveness; no alteration of architecture of the spine; avoidance of fusion; preservation of neck motion and ASD; no risk of damage to anterior structures; cost effectiveness Incomplete decompression; deterioration of pathology at index level; facet violation
CDA ? Motion preservation; avoidance of non-union; prevention of adjacent segmental degeneration Ectopic ossification; progressive decrease of neck motion; no long-term follow-up

A randomised controlled trial using an active control found some improvement at 3-4 months over conservative therapy, but none at 12 months. Only 8% had complete relief, 19% improved, 42% unchanged and 31% worse.[19]

Surgery might be considered for chronic symptoms, progressive motor weakness, or cervical myelopathy, but it shouldn't be promoted as a cure for the majority of cases.

See Also

References

  1. 1.0 1.1 1.2 1.3 1.4 Bogduk. The anatomy and pathophysiology of neck pain. Physical medicine and rehabilitation clinics of North America 2011. 22:367-82, vii. PMID: 21824580. DOI.
  2. Manchikanti L, et al. Epidural Interventions in the Management of Chronic Spinal Pain: American Society of Interventional Pain Physicians (ASIPP) Comprehensive Evidence-Based Guidelines. Pain Physician. 2021 Jan;24(S1):S27-S208. PMID: 33492918.
  3. 3.0 3.1 3.2 3.3 Kang, Kyung-Chung; Lee, Hee Sung; Lee, Jung-Hee (2020-12). "Cervical Radiculopathy Focus on Characteristics and Differential Diagnosis". Asian Spine Journal. 14 (6): 921–930. doi:10.31616/asj.2020.0647. ISSN 1976-1902. PMC 7788378. PMID 33373515. Check date values in: |date= (help)
  4. 4.0 4.1 Slipman CW, Plastaras CT, Palmitier RA, Huston CW, Sterenfeld EB. Symptom provocation of fluoroscopically guided cervical nerve root stimulation. Are dynatomal maps identical to dermatomal maps? Spine (Phila Pa 1976). 1998 Oct 15;23(20):2235-42. doi: 10.1097/00007632-199810150-00019. PMID: 9802168.
  5. 5.0 5.1 5.2 Mizutamari et al.. Corresponding scapular pain with the nerve root involved in cervical radiculopathy. Journal of orthopaedic surgery (Hong Kong) 2010. 18:356-60. PMID: 21187551. DOI.
  6. 6.0 6.1 6.2 6.3 6.4 Henderson CM, Hennessy RG, Shuey HM Jr, Shackelford EG. Posterior-lateral foraminotomy as an exclusive operative technique for cervical radiculopathy: a review of 846 consecutively operated cases. Neurosurgery. 1983 Nov;13(5):504-12. doi: 10.1227/00006123-198311000-00004. PMID: 6316196.
  7. 7.0 7.1 Rainville et al.. Exploration of sensory impairments associated with C6 and C7 radiculopathies. The spine journal : official journal of the North American Spine Society 2016. 16:49-54. PMID: 26253986. DOI.
  8. 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 YOSS RE, CORBIN KB, MACCARTY CS, LOVE JG. Significance of symptoms and signs in localization of involved root in cervical disk protrusion. Neurology. 1957 Oct;7(10):673-83. doi: 10.1212/wnl.7.10.673. PMID: 13477342.
  9. 9.0 9.1 McGee, Steven R. Evidence-based physical diagnosis. Philadelphia, PA: Elsevier, 2018.
  10. Tong HC, Haig AJ, Yamakawa K. The Spurling test and cervical radiculopathy. Spine (Phila Pa 1976). 2002 Jan 15;27(2):156-9. doi: 10.1097/00007632-200201150-00007. PMID: 11805661.
  11. Rubinstein SM, Pool JJ, van Tulder MW, Riphagen II, de Vet HC. A systematic review of the diagnostic accuracy of provocative tests of the neck for diagnosing cervical radiculopathy. Eur Spine J. 2007 Mar;16(3):307-19. doi: 10.1007/s00586-006-0225-6. Epub 2006 Sep 30. PMID: 17013656; PMCID: PMC2200707.
  12. 12.0 12.1 Stoker, Geoffrey E.; Kim, Han Jo; Riew, K. Daniel (2014-02). "Differentiating c8-t1 radiculopathy from ulnar neuropathy: a survey of 24 spine surgeons". Global Spine Journal. 4 (1): 1–6. doi:10.1055/s-0033-1354254. ISSN 2192-5682. PMC 3908974. PMID 24494175. Check date values in: |date= (help)
  13. Cohen & Hooten. Advances in the diagnosis and management of neck pain. BMJ (Clinical research ed.) 2017. 358:j3221. PMID: 28807894. DOI.
  14. Pain in the neck and arm: a multicentre trial of the effects of physiotherapy, arranged by the British Association of Physical Medicine. Br Med J. 1966 Jan 29;1(5482):253-8. doi: 10.1136/bmj.1.5482.253. PMID: 5322503; PMCID: PMC1843524.
  15. Goldie I, Landquist A. Evaluation of the effects of different forms of physiotherapy in cervical pain. Scand J Rehabil Med. 1970;2(2):117-21. PMID: 5523822.
  16. Kuijper B, Tans JT, Beelen A, Nollet F, de Visser M. Cervical collar or physiotherapy versus wait and see policy for recent onset cervical radiculopathy: randomised trial. BMJ. 2009 Oct 7;339:b3883. doi: 10.1136/bmj.b3883. PMID: 19812130; PMCID: PMC2758937.
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