What is the origin of radicular pain from the top of the inner left shoulder to the mid forearm on the radial side of the arm?

Origin of Radicular Pain from Inner Left Shoulder to Mid Forearm on Radial Side

Radicular pain from the top of the inner left shoulder to the mid forearm on the radial side of the arm is most likely caused by cervical nerve root irritation or compression, specifically involving the C6 nerve root. 1, 2

Clinical Anatomy and Pathophysiology

The pattern of pain described follows a specific cervical dermatome distribution:

• C6 nerve root involvement is the most likely culprit, as it innervates:
  • The lateral aspect of the arm
  • The radial forearm
  • The thumb and index finger

This radicular pain pattern results from:

• Irritation or compression of the cervical spine nerve root or dorsal root ganglion 3
• Pathophysiology involving both mechanical compression and chemical inflammation 3
• Commonly caused by cervical disc herniation, cervical spondylosis, or foraminal stenosis 1, 2

Diagnostic Considerations

Key Clinical Tests

• Spurling test: Extension and rotation of the neck toward the affected side reproduces radicular symptoms 3
• Shoulder abduction test: Relief of symptoms when the arm is placed on top of the head 3
• Neurological examination: Assessment for motor weakness, sensory changes, and reflex abnormalities in the C6 distribution 2

Imaging Studies

• MRI without contrast is the gold standard for assessing cervical radiculopathy 1, 2
  • Provides detailed visualization of nerve roots, discs, and surrounding soft tissues
  • Should be obtained prior to any interventional treatments 3
• CT scan (94-100% sensitivity) is superior for evaluating:
  • Bony foraminal narrowing
  • Ossification of posterior longitudinal ligament (OPLL)
  • Spinal canal dimensions 2
• Plain radiographs may serve as an initial screening tool but have limited sensitivity (49-82%) 2

Laboratory Assessment

• ESR and CRP should be obtained to assess for inflammatory processes 2
• WBC count with differential helps detect infection 2
• Blood cultures if infection is suspected 2

Differential Diagnosis

Important to differentiate cervical radiculopathy from:

• Shoulder pathology (rotator cuff disease, impingement) 4
• Brachial plexopathy 1
• Thoracic outlet syndrome 1
• Peripheral nerve entrapment syndromes

Treatment Approach

First-Line Management

1. Conservative therapy (effective in 75-90% of cases) 2:

   • NSAIDs at lowest effective dose for shortest duration
   • Activity modification
   • Physical therapy with neck-specific exercises
   • Patient education and reassurance

2. Exercise therapy (2-3 times weekly) 2:

   • Scapular resistance exercises
   • Neck-specific exercises
   • Postural correction exercises
   • General physical activity

Second-Line Interventions

For persistent symptoms after 6-12 weeks of conservative treatment:

• Interlaminar cervical epidural steroid injection for subacute cervical radicular pain 3, 5

  • Note: Transforaminal approach is NOT recommended due to safety concerns 5

• Pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for chronic cervical radicular pain 3, 5

  • If effect is insufficient, conventional radiofrequency treatment may be considered 5

Surgical Considerations

Indicated for:

• Severe symptoms with evidence of cord compression 2
• Progressive or profound motor weakness 2
• Persistent radicular pain after 6-12 weeks of conservative treatment 2

Surgical options include:

• Anterior Cervical Discectomy with Fusion (ACDF) for severe foraminal narrowing 2
• Posterior laminoforaminotomy for lateral disc herniations 2

Common Pitfalls and Caveats

1. Misdiagnosis: Cervical radiculopathy is often confused with shoulder pathology due to similar pain patterns 4

   • Careful neurological examination is essential for differentiation

2. Overreliance on imaging: MRI findings may not correlate with the patient's symptoms 3

   • Clinical correlation is crucial for accurate diagnosis

3. Premature invasive treatment: Most cases (75-90%) improve with conservative therapy 2

   • Interventional procedures should be reserved for persistent symptoms

4. Inadequate pain control: Radicular pain may require specific neuropathic pain medications, though evidence for their efficacy is limited 3

5. Overlooking "red flags": Important to identify signs of serious pathology requiring urgent intervention:

   • Fever with elevated inflammatory markers
   • Progressive neurological deficits
   • Signs of spinal cord compression

By following this structured approach to diagnosis and treatment, most patients with cervical radicular pain can achieve significant improvement in symptoms and quality of life.