import { HighYieldBox, ExamCheatSheet, Tabs, Tab, ComparisonTable, VivaScenario, ContentSection, SpecialTestCard , MedicalImage} from '@/components/content' # Lumbar Disc Herniation Examination Lumbar disc herniation examination requires systematic neurological assessment and provocative testing. Examiners expect you to perform the straight leg raise correctly, recognize the difference between L4, L5, and S1 radiculopathy, and always screen for cauda equina syndrome. ## Quick Reference One-Pager ## Anatomy and Pathophysiology **Lumbar Root Anatomy:** - Roots exit BELOW their numbered vertebra - L4 root exits at L4-5 foramen - L5 root exits at L5-S1 foramen **Disc Herniation Patterns:** - **Posterolateral** (most common): Compresses traversing root - L4-5 posterolateral disc → L5 root - L5-S1 posterolateral disc → S1 root - **Far lateral/Foraminal**: Compresses exiting root - L4-5 far lateral disc → L4 root - **Central**: May affect multiple roots, cauda equina risk **Prevalence:** - L5-S1: Most common level - L4-5: Second most common - Higher levels less common **Cauda Equina Syndrome - Surgical Emergency:** Screen EVERY patient with lumbar symptoms: - **Saddle anesthesia** (perineal numbness) - **Bladder dysfunction** (retention, incontinence) - **Bowel dysfunction** (incontinence) - **Bilateral leg symptoms** - **Progressive motor weakness** If present → URGENT MRI and neurosurgical referral ## Clinical Assessment **Typical Disc Herniation:** - Leg pain greater than back pain - Pain radiating below knee (sciatica) - Dermatomal distribution - Worse with sitting, flexion, Valsalva - Better with standing, extension, lying flat **Aggravating Factors:** - Sitting (increases disc pressure) - Forward bending (flexion) - Coughing, sneezing, straining (Valsalva) **Relieving Factors:** - Standing, walking - Lying flat - Extension ## Provocative Tests **SLR Interpretation:** - **Positive**: Leg pain (below knee) between 35-70° - **Negative**: Back pain only, or leg pain above 70° or below 35° - Pain at less than 35° suggests malingering or sciatic nerve tumor - Pain at greater than 70° is likely hamstring tightness, not root tension - Must reproduce the patient's typical radicular symptoms ## Neurological Examination by Root **Quick Root Differentiation:** - **L4**: "Kick out" (quad) + knee jerk + medial leg - **L5**: "Big toe up" (EHL) + NO reflex + dorsum foot - **S1**: "Stand on toes" (calf) + ankle jerk + sole/lateral foot **Memory Aid:** - L4 = 4-headed muscle (quads) + knee jerk - L5 = 5 toes (great toe up) - S1 = Stand (on toes), S for Soleus ## Motor Testing **L4 - Quadriceps (Knee Extension):** - Patient seated, extends knee against resistance - Also test hip adductors **L5 - Extensor Hallucis Longus (Great Toe Extension):** - "Bend your big toe up toward your head" - Most sensitive for L5 (isolated muscle) - Also test ankle dorsiflexion (tibialis anterior shares L4/L5) **S1 - Gastrocnemius/Soleus (Plantarflexion):** - Single heel raise test (can they stand on toes?) - Plantar flexion against resistance - Also test hip extension (gluteus maximus) ## Cauda Equina Examination **Always test in suspected disc herniation:** **Saddle Sensation:** - Test perianal sensation (S2-5) - "Is this numb compared to your thigh?" - Compare both sides **Anal Tone:** - Digital rectal examination - Note resting tone and voluntary squeeze - Document in all cases of bilateral symptoms **Bladder Function:** - Ask about retention (can't void), incontinence - Check for palpable bladder (distended) - Post-void residual if available ## Differential Diagnosis back, dermatomal", slr: "Positive 35-70°", motor: "Myotomal weakness", reflex: "Decreased at level" }, { condition: "Lumbar Stenosis", pain: "Both legs, neurogenic claudication", slr: "Usually negative", motor: "May be normal", reflex: "May be decreased" }, { condition: "Piriformis Syndrome", pain: "Buttock to leg", slr: "May be positive", motor: "Normal", reflex: "Normal" }, { condition: "Hip OA", pain: "Groin, anterior thigh", slr: "Negative", motor: "Normal", reflex: "Normal" }, { condition: "Spondylolisthesis", pain: "Back > leg", slr: "Variable", motor: "May be affected", reflex: "Variable" }, { condition: "Tumor/Infection", pain: "Constant, night pain", slr: "Variable", motor: "May be progressive", reflex: "Variable" } ]} /> ## Summary Presentation ## Examination Sequence 1. **Observation**: Posture, antalgic lean, muscle wasting 2. **Gait**: Antalgic, foot drop (L5), heel walk (L5), toe walk (S1) 3. **Active ROM**: Flexion, extension, lateral flexion 4. **SLR**: Both sides, note angle and distribution 5. **Crossed SLR**: If SLR positive 6. **Bowstring**: If SLR positive and want confirmation 7. **Femoral stretch**: If upper lumbar symptoms 8. **Motor**: Quads (L4), EHL (L5), calf (S1) 9. **Sensory**: Dermatomal distribution 10. **Reflexes**: Knee (L4), ankle (S1) 11. **Cauda equina screen**: Saddle, bladder, bowel ## L4 vs L5 vs S1 Quick Reference ## Examiner Tips