35: Lumbosacral plexopathy

Question 1

What nerve root are the iliohypogastric and ilioinguinal nerves derived from?

Answer 1

L1

Question 2

What is the most common non-structural cause of lumbosacral plexopathy?

Answer 2

DM (diabetic amyotrophy)

Question 3

What part of the lumbar plexus tends to get affected with retroperitoneal hemorrhage?

Answer 3

Femoral nerve

Question 4

Postpartum lumbosacral plexopathy tends to affect which nerves? What factors could predispose someone to this?

Answer 4

Peroneal fibers of sciatic nerve, superior gluteal, lumbosacral trunk (L4-5);
large fetal head with small maternal pelvis, small mother, prolonged or difficult labor

Question 5

Underlying pathology for diabetic amyotrophy? What nerves are most commonly affected?

Answer 5

Microscopic vasculitis leading to nerve ischemia;

femoral and obturator nerves

Question 6

What is underlying pathology in most cases of meralgia paresthetica?

Answer 6

Entrapment at inguinal ligament

Question 7

What is key for differentiating plexus from radic?

Answer 7

SNAP’s and EMG eval of the paraspinal muscles