Meralgia paresthetica results from entrapment of which nerve?

Meralgia paresthetica results from entrapment of which nerve?

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

Answer: (B)

Meralgia paresthetica is caused by compression of a sensory nerve that supplies the skin of the lateral thigh. The lateral femoral cutaneous nerve runs near the anterior superior iliac spine and under the inguinal ligament, so tight clothing, obesity, or prolonged standing can compress it. When this nerve is compressed, you get burning, numbness, or tingling on the anterolateral thigh, but motor function is preserved because this nerve is purely sensory. This distinguishes it from entrapment of other nerves: the sciatic nerve would produce posterior thigh and leg symptoms with potential motor weakness; the femoral nerve would cause weakness of hip flexion and knee extension with sensory loss in the anterior thigh and medial leg; the obturator nerve would affect thigh adduction. Therefore, the nerve involved is the lateral femoral cutaneous nerve.

Meralgia paresthetica is caused by compression of a sensory nerve that supplies the skin of the lateral thigh. The lateral femoral cutaneous nerve runs near the anterior superior iliac spine and under the inguinal ligament, so tight clothing, obesity, or prolonged standing can compress it. When this nerve is compressed, you get burning, numbness, or tingling on the anterolateral thigh, but motor function is preserved because this nerve is purely sensory. This distinguishes it from entrapment of other nerves: the sciatic nerve would produce posterior thigh and leg symptoms with potential motor weakness; the femoral nerve would cause weakness of hip flexion and knee extension with sensory loss in the anterior thigh and medial leg; the obturator nerve would affect thigh adduction. Therefore, the nerve involved is the lateral femoral cutaneous nerve.