Cervical Radiculopathy

Definition and Pathophysiology

1. Disk herniation - more common in patients under 45. An acute soft disk protrudes posterolaterally into the neural foramen.
2. Neuroforaminal stenosis from spondylosis - more common with increasing age. Osteophyte formation, facet joint arthropathy, and uncovertebral joint hypertrophy progressively narrow the foramen.

• Harrison's Principles of Internal Medicine 22E, p. 174
• Bradley and Daroff's Neurology in Clinical Practice, p. 2568

Clinical Presentation

• Pain originating in the neck radiating down the arm (radicular arm pain)
• Dysesthesias, paresthesias, numbness in a dermatomal distribution
• Limb weakness in the affected myotome
• Subscapular or interscapular pain (especially C6, C7, C8, T1)
• Pain worsens with Valsalva maneuver or coughing
• Neck pain alone (especially at C4 and above)

Cervical disk disease on imaging: (A) X-ray showing disk height reduction at C5/C6; (B) MRI showing herniated disk compressing spinal cord; (C-D) Spondylosis with osteophytic spurs and thickened ligamentum flavum - Harrison's Principles, Fig. 19-1

Root-Level Localization Table

Note: "Inverted" biceps reflex (absent biceps reflex with paradoxical finger flexor contraction) suggests coexisting myelopathy at C5-C6.

• Bradley and Daroff's Neurology in Clinical Practice, p. 2569

Physical Examination

• Spurling test (Spurling maneuver): Neck extension + ipsilateral rotation + axial compression reproduces or worsens arm pain. Highly specific for cervical radiculopathy. A 2025 systematic review and meta-analysis (PMID 39938056) confirmed its diagnostic value for subacute and chronic cervical radiculopathy.
• Shoulder abduction relief sign: Placing the ipsilateral hand on the head relieves pain (reduces root tension).
• Neck distraction test: Manual axial traction of the head reduces radicular symptoms.

Diagnostic Testing

Imaging

• Cervical plain films: Little value in diagnosing or excluding radiculopathy.
• MRI cervical spine: Study of choice - identifies nerve root compression in the neural foramina and assesses for myelopathy. Must be interpreted cautiously, as degenerative changes are common in asymptomatic individuals.
• CT myelography: Sometimes more sensitive than MRI; preferred in patients with MRI incompatibility (pacemakers, spinal cord stimulators), severe claustrophobia, or prior hardware from cervical fusion. Better for distinguishing osteophytes from soft disk herniation and for detecting lateral foraminal pathology missed by MRI.

Electrodiagnostics (EMG/NCS)

• Key NCS pattern: Reduced amplitude of compound muscle action potential (CMAP) with preserved sensory nerve action potential (SNAP). This dissociation occurs because the dorsal root ganglion (DRG) lies distal to the site of intraspinal compression - the sensory axon remains in continuity with its cell body, so antidromic sensory conduction is preserved.
• Needle EMG: Denervation (fibrillations, positive sharp waves) in muscles of the affected myotome, including paraspinal muscles.
• Bradley and Daroff's Neurology, p. 2569-2570

Differential Diagnosis

• Brachial plexopathy (Parsonage-Turner syndrome / brachial neuritis) - acute onset severe pain, patchy neurologic signs, EMG confirms
• Thoracic outlet syndrome - vague shoulder pain, C8/T1 distribution, positional provocation
• Peripheral nerve entrapment (carpal tunnel, cubital tunnel) - distal sensory symptoms, NCS distinguishes
• Shoulder pathology (rotator cuff disease, calcific tendinitis) - may coexist; local anesthetic injection helps differentiate
• Cervical myelopathy - bilateral symptoms, hyperreflexia below the lesion, Babinski sign, bladder dysfunction
• Firestein & Kelley's Textbook of Rheumatology, p. 8888-8904

Management

Conservative (First-Line)

• Activity modification: Avoid postures and movements that exacerbate symptoms.
• Analgesics: NSAIDs, acetaminophen; short-course opioids if needed.
• Muscle relaxants: May help with associated cervical muscle spasm.
• Oral corticosteroids: A 7-10 day course of methylprednisolone or prednisone is commonly prescribed for acute radiculopathy, though efficacy has not been definitively demonstrated in controlled trials.
• Cervical collar: Soft or hard collar use is controversial - no clear evidence for or against.
• Physical therapy: Cervical traction, McKenzie exercises, postural correction. A 2025 systematic review (PMID 40576779) found both articular and neural mobilization techniques effective for managing cervical radicular pain, with neural mobilization showing network meta-analysis superiority.

Interventional

• Epidural steroid injections (ESI): Effective for chronic cervical radiculopathy when other treatments have failed. Transforaminal or interlaminar approach under fluoroscopic guidance.
• Selective nerve root block: Both diagnostic and therapeutic.

Surgical

• Progressive neurological deficit (especially progressive motor weakness)
• Refractory, disabling pain unresponsive to conservative treatment (typically after 6-12 weeks)
• Acute or progressive signs of myelopathy

• Anterior cervical discectomy and fusion (ACDF): Most common approach; addresses ventral pathology.
• Total disk arthroplasty (TDA): Alternative to fusion at single levels, preserves motion.
• Posterior cervical laminoforaminotomy: Effective for foraminal stenosis, preserves motion, avoids anterior approach.

• Tintinalli's Emergency Medicine, p. 1925
• Rheumatology 2-Volume Set (Elsevier 2022), p. 1574-1581
• Bradley and Daroff's Neurology, p. 2570-2571

Indications for Urgent/Emergent Referral

• Progressive upper extremity weakness (especially C7 distribution)
• Acute or progressive signs of myelopathy (bilateral weakness, gait disturbance, hyperreflexia, Babinski, bladder/bowel involvement)
• Intractable radicular pain unresponsive to treatment
• Red flags suggesting malignancy or infection (constitutional symptoms, history of cancer, fever, weight loss)

Key Points Summary

Normal MRI in Suspected Cervical Radiculopathy: What to Do

Why MRI Can Be Normal

• Prior cervical hardware/fusion implants (metal artifact)
• Motion artifact in anxious or uncooperative patients
• Field strength (1.5 T vs. 3 T)
• Protocol gaps (missed dedicated coronal foraminal cuts)

• Bradley and Daroff's Neurology in Clinical Practice, p. 2570

Step-by-Step Approach

Step 1 - Proceed to EMG/NCS (Most Important Next Step)

"Root compression resulting in intermittent ischemia or mechanical deformation may result in isolated root demyelination without secondary axonal loss. In this scenario, a patient may experience classical radicular symptoms without any objective evidence of the disease."

• Bradley and Daroff's Neurology in Clinical Practice, p. 2570

Step 2 - Consider Alternative Imaging

• CT myelography: Sometimes more sensitive than MRI for bony foraminal stenosis, osteophyte-mediated compression, and lateral pathology. Particularly useful if prior cervical hardware is degrading MRI quality. Better at distinguishing calcified vs. soft disk herniation.
• Flexion-extension or dynamic views: May reveal instability contributing to intermittent root compression that is not evident on static MRI.
• Higher-field MRI (3 T) or dedicated foraminal protocol: If the original scan was 1.5 T or lacked dedicated foraminal imaging, upgrading the technique is worthwhile.
• MRI brachial plexus: If the clinical picture is more consistent with plexopathy than radiculopathy (patchy, multi-root distribution; no paraspinal EMG changes), dedicated plexus MRI to exclude structural plexus lesion.
• Goldman-Cecil Medicine, Ancillary Testing section
• Bradley and Daroff's Neurology, Diagnostic Testing

Step 3 - Revisit the Differential Diagnosis

• Radiculopathy: fibrillations present in paraspinal muscles (proximal to DRG)
• Plexopathy: paraspinal muscles normal (lesion is distal to DRG)
• Bradley and Daroff's Neurology, p. 2614-2615

Step 4 - Treat Clinically If Diagnosis Fits

• Proceed with conservative management - there is no harm in treating the clinical syndrome. Most cervical radiculopathy improves in 4-8 weeks regardless of treatment.
• NSAIDs, short-course oral steroids (7-10 days), physical therapy, activity modification.
• Epidural steroid injection can be both diagnostic and therapeutic - reproduction of symptoms + relief confirms the level.

"Patients with a typical clinical presentation and little or no neurological deficit usually can be managed with these noninvasive approaches without imaging or EDX studies."

• Bradley and Daroff's Neurology in Clinical Practice, p. 2571

Step 5 - Red Flags Requiring Urgent Escalation

• Progressive weakness - myelopathy or motor neuron disease must be excluded regardless of MRI
• Constitutional symptoms (fever, weight loss, night sweats) - spinal infection or malignancy; MRI can have up to a 17% false-negative rate for spinal metastases
• Bilateral symptoms or long-tract signs - do not accept a normal standard MRI; request gadolinium-enhanced MRI and specialist review
• Bladder/bowel involvement - emergency evaluation

Summary Algorithm

Cervical Radiculopathy Suspected
           ↓
       MRI NORMAL
           ↓
    ┌──────────────────────────────────────────────┐
    │ 1. Timing? → Wait ≥2 weeks from onset for EMG│
    │ 2. EMG/NCS → Confirm root level, exclude      │
    │    plexopathy/peripheral nerve                │
    │ 3. Reconsider differential diagnosis          │
    │ 4. If MRI suboptimal → CT myelography         │
    │    or higher-field/protocol MRI               │
    │ 5. Treat conservatively if clinical fit       │
    │ 6. Epidural steroid: diagnostic + therapeutic │
    │ 7. Red flags? → Urgent specialist referral    │
    └──────────────────────────────────────────────┘