What are the symptoms and treatment options for nerve root compression?

Symptoms of Nerve Root Compression

Nerve root compression presents with radiculopathy—a triad of radiating pain in a dermatomal distribution, sensory dysfunction (numbness/tingling), and motor weakness with diminished reflexes in the affected nerve root distribution. 1

Core Clinical Features

Pain Characteristics

• Sciatica (lumbar): Pain radiating down the leg below the knee in the sciatic nerve distribution, indicating nerve root compromise from mechanical pressure or inflammation 1
• Cervical radiculopathy: Arm pain radiating in a dermatomal pattern, often accompanied by neck pain 2
• Pain is the predominant symptom and the primary indication for treatment, more so than weakness 3

Sensory Symptoms

• Dermatomal sensory impairment: Numbness, tingling, or paresthesias following specific nerve root distributions 1
• Sensory symptoms are often diffuse and overlap between adjacent nerve roots (e.g., C6 vs C7 radiculopathy symptoms are not distinctly different) 4
• Caution: Symptom location alone has limited value for predicting specific root involvement due to significant overlap 4

Motor Dysfunction

• Weakness in muscle groups corresponding to the affected nerve root 1, 2
• Diminished deep tendon reflexes in the nerve root distribution 1
• Only 41% of patients report subjective weakness, and specific weakness complaints have limited diagnostic value for differentiating between nerve root levels 4
• Younger patients with lesser weakness for shorter duration respond better to treatment than older patients with greater, longer-standing weakness 3

Special Syndrome: Cauda Equina

Cauda equina syndrome is a surgical emergency resulting from compression of sacral and lumbar nerve roots, presenting with: 1

• Bladder, bowel, or sexual dysfunction (urinary retention or incontinence from sphincter loss)
• Saddle anesthesia (perianal or saddle numbness)
• Bilateral lower extremity motor weakness
• Absent lower limb reflexes
• Back pain with or without radicular symptoms is the most common physical finding 1

Spinal Stenosis-Specific Symptoms

• Neurogenic claudication: Leg pain and occasionally weakness with walking or standing, relieved by sitting or spinal flexion 1
• Results from bony constriction of the cauda equina and emerging nerve roots 1

Pathophysiology

Compression affects nerve root structure and function through: 5

• Direct mechanical pressure on nerve fibers
• Impaired blood flow and nutrition to the nerve root
• Edema formation in the nerve root
• Interaction between biomechanical and microvascular mechanisms 6

Diagnostic Approach

Physical Examination

• Straight-leg-raise test (lumbar): Hip flexion with knee extended reproduces sciatica between 30-70 degrees, indicating nerve root tension 1
• Crossed straight-leg-raise: Reproduction of sciatica when lifting the unaffected leg is highly specific 1
• Document specific dermatomal sensory loss, myotomal weakness, and reflex changes 7

Imaging

• MRI without contrast is the gold standard for evaluating nerve root compression, accurately depicting soft-tissue pathology and assessing spinal canal patency 1, 2
• Urgent MRI is required for suspected cauda equina syndrome 1
• CT offers superior bone visualization and is complementary for assessing osseous causes of compression 2
• Critical pitfall: MRI findings must correlate with clinical symptoms—false positives and negatives are common, as disc abnormalities appear in 20-28% of asymptomatic patients 1, 2

Treatment Framework

Conservative Management (First-Line)

• 75-90% of patients achieve symptomatic improvement with non-operative treatment 2, 3
• Minimum 6 weeks of conservative therapy required before considering surgery, including physical therapy, anti-inflammatory medications, activity modification, and possible cervical collar immobilization 2, 7
• At 12 months, physical therapy achieves comparable outcomes to surgery, though surgery provides more rapid relief (3-4 months) 2

Surgical Indications

• Persistent symptoms despite 6+ weeks of conservative treatment 2, 7
• Significant functional deficit impacting quality of life 2
• Progressive neurological deficits 2
• Cauda equina syndrome (immediate surgical emergency) 1
• Pain is the main indication for surgery, not weakness alone 3

Surgical Outcomes

• 80-90% success rate for arm pain relief in cervical radiculopathy 2
• 90.9% functional improvement following surgical intervention 2
• Younger patients with shorter symptom duration have better surgical outcomes 3