What is the likely diagnosis for a patient with a history of chronic heavy lifting, presenting with lumbar pain, weakness, and paresthesia in the lower limbs?

Lumbar Disc Herniation with Radiculopathy

Your patient most likely has lumbar disc herniation with radiculopathy, given the classic triad of chronic heavy lifting history, lumbar pain, and lower extremity weakness with paresthesia. 1

Clinical Diagnosis

The combination of lumbar pain radiating to the lower limbs with weakness and paresthesia has high sensitivity for herniated disc causing nerve root compression. 1 This presentation is distinct from other causes:

• More than 90% of symptomatic lumbar disc herniations occur at L4-L5 and L5-S1 levels, making these the most likely locations in your patient 2, 1
• The history of chronic heavy lifting is a classic risk factor for disc herniation 3
• Radiculopathy presents as back pain radiating down the leg in a typical nerve root distribution, which your patient demonstrates 1

Key Examination Findings to Assess

Perform a focused neurological examination to localize the affected nerve root:

• Assess knee strength and reflexes (L4 nerve root) 1
• Test great toe and foot dorsiflexion strength (L5 nerve root) 1
• Evaluate foot plantarflexion and ankle reflexes (S1 nerve root) 1
• Map the distribution of sensory symptoms to determine which dermatome is affected 1
• Perform straight leg raise test: 91% sensitivity but only 26% specificity for disc herniation 4, 1
• Consider crossed straight leg raise: more specific (88%) but less sensitive (29%) 1

Differential Diagnosis to Exclude

Spinal Stenosis

• Spinal stenosis typically presents with pseudoclaudication that improves with forward flexion, not the pattern your patient likely has 4, 1
• Pain in stenosis improves with sitting/forward flexion because this position increases spinal canal diameter 4
• More common in patients over 65 years (positive likelihood ratio 2.5) 4

Cauda Equina Syndrome (Red Flag)

Immediately assess for urinary retention, fecal incontinence, and saddle anesthesia - these require urgent MRI and surgical evaluation 5, 1

Initial Management Approach

Do NOT order immediate imaging unless red flags are present. 2, 1 Most patients improve within the first 4 weeks with conservative management 2, 1.

Conservative Treatment (First 4-6 Weeks)

Pharmacologic interventions:

• NSAIDs are first-line with good evidence for moderate pain relief - optimize dosing to 600-800mg three times daily rather than subtherapeutic twice-daily dosing 2, 1
• Add skeletal muscle relaxant for short-term use if muscle spasm is present 4, 1
• Acetaminophen as adjunctive therapy (fair evidence) 1

Non-pharmacologic interventions:

• Advise patient to remain active - bed rest is less effective than staying active 4, 2
• Superficial heat has good evidence for moderate benefits 1
• Physical therapy including exercise therapy shows effectiveness 4, 1
• Spinal manipulation by appropriately trained providers for small to moderate short-term benefits 4, 1

Critical Pitfall to Avoid

Do NOT rush to epidural steroid injections - the most recent high-quality BMJ guideline provides a strong recommendation AGAINST epidural injection of local anesthetic, steroids, or their combination for radicular spine pain 1

When to Order MRI

MRI lumbar spine without IV contrast is indicated only if:

1. Symptoms persist beyond 4-6 weeks despite conservative management AND the patient is a candidate for surgery or epidural steroid injection 5, 2, 1
2. Severe or progressive neurological deficits develop (progressive motor weakness, particularly knee extension for L4 or foot drop for L5) 2, 1
3. Red flags are present: suspected cauda equina syndrome, cancer (history of cancer, unexplained weight loss, age >50, failure to improve after 1 month), infection (fever, IV drug use), or compression fracture (osteoporosis, steroid use) 1

MRI is the imaging study of choice because it accurately depicts soft-tissue pathology, assesses vertebral marrow, and evaluates spinal canal patency. 5

Surgical Referral Timing

Refer for surgical evaluation if:

• Persistent radicular symptoms after 4-6 weeks of conservative treatment with significant functional limitations 4
• Progressive neurological deficits (worsening weakness) 4, 2
• Concordant MRI findings showing significant stenosis or disc herniation that correlate with clinical presentation 4

At least 6 weeks of conservative therapy is recommended before considering surgery unless severe or rapidly progressive neurological deficits are present 1

Follow-up Plan

Reassess in 1 month if symptoms persist without improvement. 2 Earlier reevaluation is warranted if:

• Neurological deficits develop or worsen 2
• Pain becomes severe and refractory to treatment 2
• Any red flag symptoms emerge 1