Meralgia Paresthetica
Meralgia Paresthetica is an entrapment neuropathy of the Lateral Femoral Cutaneous Nerve (LFCN). It causes burning pain, numbness, and tingling in the outer thigh.
1. Anatomy
- Nerve: Lateral Femoral Cutaneous Nerve (L2, L3).
- Entrapment Site: Usually where the nerve passes under the Inguinal Ligament, near the ASIS.
2. Causes ("Skinny Jean Syndrome")
- Tight clothing (belts, jeans).
- Obesity (Panniculus pressing on the ligament).
- Pregnancy.
- Seatbelt injury.
3. Clinical Features
- Sensory ONLY: The LFCN is purely sensory. No motor weakness.
- Pain: Burning/stinging on the anterolateral thigh. Worsened by standing/walking (hip extension stretches the nerve).
- Tinel's Sign: Positive over the ASIS/Inguinal ligament.
4. Management
- Conservative: Remove compression (loose clothes, weight loss). NSAIDs. Nerve blocks.
- Surgery: Neurolysis or Neurectomy (if intractable).
25 Practice MCQs
Q1. Meralgia Paresthetica affects which nerve?
Answer: A). Purely sensory nerve.
Q2. The root value of LFCN is:
Answer: A). From the lumbar plexus.
Q3. The most common site of entrapment is:
Answer: A). Compression against the iliac crest.
Q4. Motor weakness in the quadriceps rules out Meralgia Paresthetica. True/False?
Answer: A). LFCN is strictly sensory. Motor loss suggests Femoral nerve or L3/L4 radiculopathy.
Q5. Typical symptoms include:
Answer: A). Paresthesia = Tingling/Numbness.
Q6. Which lifestyle factor is a common cause?
Answer: A). Anything compressing the waistline.
Q7. Symptoms are often relieved by:
Answer: A). Flexion reduces tension on the nerve.
Q8. Tinel's sign is elicited by tapping:
Answer: A). Produces electric shock down the thigh.
Q9. Differential diagnosis includes:
Answer: A). Radiculopathy usually involves back pain and motor signs; MP does not.
Q10. Weight loss is effective because:
Answer: A). A hanging belly puts traction on the inguinal region.
Q11. "Reverse Lasegue" or Femoral Stretch Test may be positive due to:
Answer: A). Extends the hip, tightening the nerve path.
Q12. Is surgery the first line of treatment?
Answer: B). >90% resolve conservatively.
Q13. Neurectomy involves:
Answer: A). Last resort. Numbness is better than burning pain.
Q14. Can diabetes cause this?
Answer: A). Double crush phenomenon.
Q15. What type of clothing aggravates it?
Answer: A). Direct external compression.
Q16. The sensory distribution involves:
Answer: A). Medial is Obturator/Femoral; Posterior is Sciatic.
Q17. Nerve conduction studies (NCS) are:
Answer: A). Often a clinical diagnosis.
Q18. Bernhardt-Roth syndrome is synonymous with:
Answer: A). Eponym.
Q19. Iliacus muscle spasm can contribute by:
Answer: A). Soft tissue release may help.
Q20. Does it affect the knee reflex?
Answer: B). Reflex is mediated by Femoral nerve (L3-L4), not LFCN.
Q21. Pregnancy-related MP usually resolves:
Answer: A). Once abdominal pressure decreases.
Q22. Lidocaine injection test is diagnostic if:
Answer: A). Confirms the site of entrapment.
Q23. Is it bilateral?
Answer: A). Usually affects the dominant side or both.
Q24. Neurolysis means:
Answer: A). Preserves sensation.
Q25. Kinesio taping can help by:
Answer: A). Symptomatic relief.
No comments:
Post a Comment