What is the most appropriate next step for a 45-year-old man with acute lower back pain radiating to the left leg and foot, numbness, and tingling, exacerbated by coughing or sneezing, with a positive straight leg raising test, and no relief from Tylenol (acetaminophen)?

Management of Radiculopathy in a 45-Year-Old Man

The most appropriate next step for this patient with signs and symptoms of lumbar radiculopathy is to obtain an MRI of the lumbar spine, as he is presenting with persistent neurological symptoms that may require surgical intervention. 1

Clinical Assessment and Diagnosis

This patient presents with classic signs of lumbar radiculopathy:

• Sharp pain in lower back for 2 weeks
• Pain radiating down left buttock to foot
• Pain exacerbated by coughing/sneezing (positive Valsalva)
• Numbness and tingling radiating down left leg to big toe
• Positive straight leg raising test on the left
• Failure to respond to acetaminophen

These symptoms strongly suggest lumbar disc herniation with nerve root compression, most likely affecting the L5 nerve root (based on big toe involvement).

Diagnostic Approach

According to the American College of Physicians and American Pain Society guidelines, MRI is the preferred imaging modality for patients with:

• Persistent symptoms of radiculopathy
• Positive neurologic findings (as in this case)
• Failure to respond to conservative management 1

The guideline specifically states: "Clinicians should perform diagnostic imaging and testing for patients with low back pain when severe or progressive neurologic deficits are present" and "evaluate patients with persistent back and leg pain who are potential candidates for invasive interventions—plain radiography cannot visualize discs or accurately evaluate the degree of spinal stenosis." 1

Why MRI is Superior to Other Options

1. MRI vs. Nerve Conduction Studies:

   • MRI directly visualizes disc herniation and nerve root compression
   • Nerve conduction studies may help confirm radiculopathy but don't identify the anatomical cause that may require surgical intervention 1

2. MRI vs. Duloxetine Therapy:

   • Starting medication without confirming diagnosis could delay appropriate treatment
   • The patient already failed first-line therapy (acetaminophen)
   • Treatment should target the underlying cause, not just symptoms

Treatment Algorithm

1. Obtain MRI to confirm diagnosis and assess severity of disc herniation
2. Based on MRI findings:
   • If severe disc herniation with significant nerve compression: consider surgical referral
   • If moderate disc herniation: consider epidural steroid injection
   • If mild disc herniation: optimize conservative management

Conservative Management Options (after MRI)

• NSAIDs (if no contraindications) 2
• Muscle relaxants for acute symptoms 2
• Consider gabapentin for neuropathic pain component 3
• Physical therapy with specific exercises
• Limited course of opioid/acetaminophen combination for severe pain 4

Important Caveats

• Avoid delaying appropriate imaging in patients with progressive neurological symptoms
• The natural history of lumbar disc herniation with radiculopathy is improvement within 4 weeks with noninvasive management in most patients 1
• If symptoms persist despite conservative management, surgical options like discectomy may be considered 1
• Routine imaging is not recommended for nonspecific back pain, but this patient has clear radicular symptoms with neurological findings

Conclusion

This patient's presentation with persistent radicular symptoms, neurological findings, and failure of conservative management warrants MRI imaging to guide further treatment decisions and determine if he is a candidate for surgical intervention or epidural steroid injection.