Which nerve is commonly associated with meralgia paresthetica when compressed?

Which nerve is commonly associated with meralgia paresthetica when compressed?

• A. Obturator nerve
• B. Femoral nerve
• C. Ilioinguinal nerve
• D. Lateral femoral cutaneous nerve

Answer: (D)

Meralgia paresthetica happens when the lateral femoral cutaneous nerve, a purely sensory branch from the lumbar plexus, is compressed as it passes under the inguinal ligament near the ASIS. This nerve supplies sensation to the anterolateral thigh, so compression produces numbness, tingling, or burning in that area while motor function remains intact because there are no motor fibers involved. The lateral thigh distribution with preserved leg strength is a key clue, and factors like tight belts or obesity can trigger it. The other nerves have different roles and territories: the obturator nerve serves the medial thigh and adductors; the femoral nerve handles the anterior thigh muscles and sensation to the medial leg; the ilioinguinal nerve supplies the groin and upper medial thigh. Therefore, compression of the lateral femoral cutaneous nerve best explains meralgia paresthetica.

Meralgia paresthetica happens when the lateral femoral cutaneous nerve, a purely sensory branch from the lumbar plexus, is compressed as it passes under the inguinal ligament near the ASIS. This nerve supplies sensation to the anterolateral thigh, so compression produces numbness, tingling, or burning in that area while motor function remains intact because there are no motor fibers involved. The lateral thigh distribution with preserved leg strength is a key clue, and factors like tight belts or obesity can trigger it. The other nerves have different roles and territories: the obturator nerve serves the medial thigh and adductors; the femoral nerve handles the anterior thigh muscles and sensation to the medial leg; the ilioinguinal nerve supplies the groin and upper medial thigh. Therefore, compression of the lateral femoral cutaneous nerve best explains meralgia paresthetica.