What are radiculopathy and spinal stenosis, and how are they diagnosed and treated?

Radiculopathy and Spinal Stenosis: Diagnosis and Testing

MRI is the preferred diagnostic imaging for patients with persistent symptoms of radiculopathy or spinal stenosis who are potential candidates for surgery or epidural steroid injection. 1

Definitions

Radiculopathy

• Radiculopathy refers to pain or sensorimotor deficit secondary to nerve root impingement and/or irritation 1
• Characterized by pain radiating along the distribution of a specific nerve root, often accompanied by sensory changes, motor weakness, or reflex changes 1
• Can be caused by herniated discs, osteophytes, or other compressive lesions 1

Spinal Stenosis

• Spinal stenosis refers to narrowing of the spinal canal, lateral recesses, or neural foramina 2
• Can be central (affecting the spinal canal), lateral (affecting the lateral recesses), or foraminal (affecting the neural foramina) 2
• Often associated with degenerative changes, spondylolisthesis, or scoliosis 2

Clinical Diagnosis

History and Physical Examination

• A focused history and physical examination should help categorize patients into one of three categories: nonspecific back pain, pain potentially associated with radiculopathy or spinal stenosis, or pain potentially associated with another specific spinal cause 1
• Assessment should include psychosocial risk factors, which predict risk for chronic disabling back pain 1

Key Clinical Features of Radiculopathy

• Pain radiating into an extremity along a dermatomal pattern 1
• Upper or lower limb pain with varying degrees of sensory or motor deficits 1
• Cervical radiculopathy presents with neck and/or upper limb pain 1
• Lumbar radiculopathy presents with low back and/or lower limb pain 1

Key Clinical Features of Spinal Stenosis

• Neurogenic claudication (pain with walking or standing that improves with sitting or flexion) 2
• Bilateral lower extremity symptoms 2
• Symptoms may worsen with extension of the spine 2

Diagnostic Testing

When to Order Imaging

• Imaging should not be routinely obtained for nonspecific back pain 1
• Imaging is indicated when:
  • Severe or progressive neurologic deficits are present 1
  • Serious underlying conditions are suspected (cancer, infection, cauda equina syndrome) 1
  • Symptoms persist despite 4 weeks of conservative treatment and patient is a candidate for surgery or epidural steroid injection 1

Preferred Imaging Modalities

• MRI is the preferred imaging modality for suspected radiculopathy or spinal stenosis 1
• MRI provides better visualization of soft tissue, vertebral marrow, and the spinal canal compared to CT 1
• CT may be used when MRI is contraindicated or unavailable 1
• Plain radiography cannot visualize discs or accurately evaluate the degree of spinal stenosis 1

Cautions with Imaging

• Imaging findings often correlate poorly with symptoms - many asymptomatic individuals have disc bulges or stenosis on imaging 1
• MRI alone should not be used to diagnose symptomatic radiculopathy and should always be interpreted in combination with clinical findings 1
• A systematic review found limited evidence for correlation between physical examination findings and MRI evidence of cervical nerve root compression 1

Special Considerations

Cervical Radiculopathy

• Most cases of acute cervical radiculopathy resolve spontaneously or with conservative treatment 1
• Cervical radiculopathy is frequently self-limiting, with 75-90% of patients achieving symptomatic relief with nonoperative conservative therapy 1
• CT offers superior depiction of bony elements but is less sensitive than MRI for evaluation of nerve root compression 1

Lumbar Radiculopathy and Stenosis

• The natural history of lumbar disc herniation with radiculopathy is improvement within the first 4 weeks with noninvasive management in most patients 1
• In degenerative lumbar scoliosis, radicular symptoms are attributed mainly to nerve roots exiting from the concavity of the lumbosacral curve 3
• L4 and L5 nerve roots are most commonly affected in lumbar spinal stenosis 4, 3

Common Pitfalls

• Relying solely on imaging findings without clinical correlation can lead to unnecessary interventions 1
• Failing to recognize that findings on MRI (such as bulging disc without nerve root impingement) are often nonspecific 1
• Not considering that radiculopathy may originate from a level different than expected based on symptoms 5
• Overlooking that 60-85% of properly selected patients have satisfactory symptomatic improvement with surgical treatment for lumbar spinal stenosis 2