Nerve Palsies in the Limbs

Question 1

What is a dermatome?

Answer 1

Sensory area of skin supplied by a single spinal nerve

Question 2

What are the S’s of Sacral dermatomes?

Answer 2

Stand on S1
Sleep on S2
Sit on S3
Shit on S4

Question 3

What is Hilton’s Law?

Answer 3

Nerves crossing a joint supply the muscles acting on it and the joint itself

Question 4

What is the innervation of the hip joint?

Answer 4

OBTURATOR NERVE
Femoral nerve
Lateral femoral cutaneous nerve

Question 5

What is a myotome?

Answer 5

Group of muscles supplied by 1 segment of spinal cord

Question 6

What is the structure of the brachial plexus?

Answer 6

Roots
Trunks
Divisions
Cords
Branches

Question 7

How do downward traction Brachial plexus lesions typically present?

Answer 7

Downward traction (fall onto shoulder)
C5, 6 damage
Waiter’s tip

Question 8

How do upward traction Brachial plexus lesions typically present?

Answer 8

Upward traction (breech delivery)
T1 damage (intrinsic muscles of hand)
Clawed hand (Klumpke's paralysis)

Question 9

Axillary Nerve injury is commonly due to what?

Answer 9

Humeral neck surgery
Shoulder dislocation
Saturday night palsy

Question 10

How does axillary nerve injury present?

Answer 10

Motor deficit - loss of shoulder abduction

Sensory Deficit - badge area

Question 11

What are the roots of the radial nerve?

Answer 11

C5 - T1

Question 12

In the arm, the Radial nerve is closely associated with what?

Answer 12

Profunda brachii

Question 13

Where does the radial nerve enter the forearm?

Answer 13

Pass between brachioradialis and brachialis

Question 14

What is saturday night palsy?

Answer 14

Falling asleep with arm over chair - compression of the posterior cord of the brachial plexus

Question 15

At what point is the radial nerve at risk?

Answer 15

Spiral groove of the humerus & lateral intermuscular septum

Question 16

Radial nerve injury is a complication of?

Answer 16

Humeral shaft break

Saturday night palsy

Question 17

What deficit is associated with radial nerve palsy?

Answer 17

Motor - wrist drop (extensors)

Sensory - 1st web space dorsally (space between thumb, 1st finger)

Question 18

What are the root values of the median nerve?

Answer 18

C7, 8

T1

Question 19

The median nerve is associated with what in the arm?

Answer 19

Brachial artery

Question 20

Where does the median nerve enter the forearm?

Answer 20

Passes between the two heads of pronator teres

Question 21

At which point is the median nerve at risk?

Answer 21

Volar aspect of the wrist

Cubital fossa

Question 22

Median nerve damage is a complication of what?

Answer 22

Wrist lacerations

Carpal tunnel syndrome

Question 23

What deficits are associated with median nerve injury?

Answer 23

Motor - thenar wasting, pointing finger

Sensory - volar aspect thumb

Question 24

What structures traverse the carpal tunnel?

Answer 24

Transverse carpal ligament
Flexor tendons
Median nerve

Question 25

What are the roots of the ulnar nerve?

Answer 25

C7, 8 | T1

Question 26

The ulnar nerve is associated with what?

Answer 26

Superior ulnar collateral artery

Question 27

How does the ulnar nerve enter the forearm?

Answer 27

Passes between two heads of flexor carpi ulnaris

Question 28

Which part of the ulnar nerve is at risk?

Answer 28

Area behind medial epicondyle of humerous

Question 29

Ulnar nerve injury is a complication of what?

Answer 29

Break at humeral condyles | Wrist laceration

Question 30

What deficit is associated with Ulnar nerve injury?

Answer 30

Motor - claw hand, hypothenar wasting, 1st dorsal interosseus wasting Sensory - little finger

Question 31

Where does the Lumbar Plexus lie?

Answer 31

Surface of quadratus lumborum | Within body of psoas major

Question 32

Where do Lumbar Plexus nerves exit the pelvis?

Answer 32

Mostly - sciatic foramen

Question 33

Which Lumbar Plexus nerves do not exit the pelvis via the sciatic foramen?

Answer 33

Genitofemoral & Ilioinguinal Femoral Lateral femoral cutaneous Obturator nerves

Question 34

What are the nerve roots of the femoral nerve?

Answer 34

L2 - 4

Question 35

What is the largest branch of the lumbar plexus?

Answer 35

Femoral nerve

Question 36

Where does the femoral nerve travel?

Answer 36

Through Psoas, exits under inguinal ligament Lateral to fermoral artery, vein, lymphatics (femoral triangle)

Question 37

What does the femoral nerve supply?

Answer 37

Quadriceps muscles of thigh

Question 38

How does the femoral nerve terminate?

Answer 38

Long fine sensory branch | Saphenous Nerve

Question 39

What does the Saphenous Nerve travel with?

Answer 39

Femoral artery in thigh Long saphenous vein in lower leg Front medial malleolus

Question 40

What does the Saphenous nerve supply?

Answer 40

Big toe

Question 41

What are the nerve roots of the Lateral Femoral Cutaneous Nerve?

Answer 41

L2, 3

Question 42

The Lateral Femoral Cutaneous Nerve lies where?

Answer 42

Surface of iliacus | Exits under lateral end of inguinal igament

Question 43

What is the function of the Lateral Femoral Cutaneous Nerve?

Answer 43

Sensory - lateral thigh

Question 44

Compression of the Lateral Femoral Cutaneous Nerve causes what?

Answer 44

Meralgia Paraesthetica

Question 45

What are the nerve roots of the Sciatic Nerve?

Answer 45

L4 - S3

Question 46

What does the Sciatic Nerve supply?

Answer 46

Hamstring muscles Adductor magnus Lower leg and foot muscles via branches

Question 47

What can put the sciatic nerve at risk?

Answer 47

Hip dislocation Intra-muscular injections Surgery

Question 48

What are the roots of the Common Fibular Nerve?

Answer 48

L4 - S3

Question 49

The Common Fibular Nerve is a branch of what?

Answer 49

Lateral branch of the sciatic nerve

Question 50

Where is the Common Fibular Nerve at risk?

Answer 50

Lateral aspect of fibula

Question 51

The Common Fibular Nerve divides into what?

Answer 51

Superficial and Deep Fibular nerves

Question 52

Common Fibular Nerve Deficit leads to what?

Answer 52

Slapping gait | Foot drop