Nerve palsies in the limbs

Question 1

How do you remember the posterior lower limb dermatomes?

Answer 1

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

Question 2

What is Hilton’s law?

Answer 2

The nerves crossing a joint supply the muscles acting on the joint and the joint itself
(May supply 2 joints so disease in one may result in pain for both)

Question 3

Which nerves supply the hip?

Answer 3

Obturator
Femoral
Lateral femoral cutaneous

Question 4

What is a myotome?

Answer 4

Group of muscles supplied by one segment of spinal cord

Question 5

Describe Erb-Duchenne paralysis.

Answer 5

Arm adducted
Forearm extended and pronated
Wrist flexed

Caused by C5,C6 damage

Question 6

Which muscles do the axillary nerve supply?

Answer 6

Deltoid
Teres Minor
Skin over lateral arm

Question 7

Why is the axillary nerve more at risk than others?

Answer 7

Wrap around surgical neck of humerus
Stretched in dislocation
May be damaged by fractured neck of humerus
Commonly affected in shoulder injury

Question 8

Which nerve supplies the triceps?

Answer 8

Radial

Question 9

How may palsy arise in the radial nerve?

Answer 9

Associated with fractures
Entrapment
Caught or transected in fractures and compound fractures
Compression e.g falling asleep with arm over chair

Question 10

What does the median nerve supply?

Answer 10

Forearm flexors
Medial half of FDP
Sensation for radial 3.5 digits

Question 11

How does motor deficit of the median nerve present?

Answer 11

Thenar wasting

Pointing finger

Question 12

How would a brachial plexus lesion affect the arm?

Answer 12

Erb-Duchenne paralysis

Question 13

How might a brachial plexus lesion affect the hand?

Answer 13

Clawed

Klumpke’s paralysis

Question 14

How would motor deficit of the axillary nerve present?

Answer 14

Affects deltoid

Loss of shoulder abduction

Question 15

How would sensory deficit of axillary nerve present?

Answer 15

Affects badge area

Question 16

How might motor deficit of the radial nerve present?

Answer 16

Affects extensors

Causes wrist drop

Question 17

How might a sensory deficit of the radial nerve present?

Answer 17

Affects 1st web space dorsally

Question 18

Where would a sensory deficit of the median nerve affect?

Answer 18

Palmar aspect of thumb

Question 19

How would a motor deficit of the ulnar nerve present?

Answer 19

Claw hand

Hypothenar and 1st dorsal interosseous wasting

Question 20

Where might a sensory deficit of the ulnar nerve affect?

Answer 20

Pinky finger

Question 21

Where does the lumbar plexus lie?

Answer 21

Surface of quadratus lumborum and within psoas muscle

Question 22

Where are the roots of the femoral nerve?

Answer 22

L2-L4

Question 23

Which nerve supplies the quadriceps muscle in the thigh?

Answer 23

Femoral

Question 24

Which nerve provides sensory innervation to lateral aspect of thigh?

Answer 24

Lateral femoral cutaneous nerve

Question 25

What is the largest nerve in the body?

Answer 25

Sciatic nerve

Question 26

Which muscles are supplied by the sciatic nerve?

Answer 26

Hamstring
Part of adductor magnus
All lower leg and foot muscle in terminal branches

Question 27

When is the sciatic nerve at risk?

Answer 27

Posterior dislocation of hip

IM injections during surgery

Question 28

Where are the roots for the sciatic nerve?

Answer 28

L4-S3

Question 29

Which nerve deficit causes foot drop and slapping gait?

Answer 29

Common fibular nerve
Small lateral branch of sciatic nerve which passes around neck of fibula
Most commonly injured lower limb nerve

Question 30

Which nerve supplies sensory innervation to most of the dorsum of the foot?

Answer 30

Superficial peroneal nerve (SPN)