Upper Limb Mononeuropathies

Question 1

Axillary nerve lesions:

What type of dislocation would cause this?

What bone fracture would cause this?

What movement is weak and why?

What area is numb?

What is this area called?

Answer 1

Anterior shoulder dislocation

Humeral head fracture

Deltoid weakness therefore impaired shoulder abduction

Sargeant’s patch numbness - lateral part of the deltoid

Question 2

Radial nerve lesions:

What bone fracture would cause this?

What equipment used to walk with a leg injury could cause this?

It supplies the extensor compartment. What 2 motor signs would you expect to see?

Answer 2

Humeral fracture

Crutches

Wrist drop
Finger drop

Question 3

Posterior interosseous nerve (PIN) lesions:

What nerve does it continue from?

What is radial tunnel syndrome? What nerve is compressed?

PIN compression syndrome:
- Where will they have a weak extension?

Answer 3

Deep branch of the radial nerve in the forearm

Pain without motor or sensory symptoms due to compression of PIN

Fingers - same as before
THUMB - used to distinguish them

Question 4

Medial nerve lesions:

Carpel tunnel syndrome is the main cause.

• What joint disease could cause this?
• What will increase body size, contributing to this?

THE MAIN SYMPTOM IS SENSORY WHICH DIFFERENTIATES IT FROM ULNAR NERVE LESIONS!

Presentation:

• What 3 fingers become numb?
• How is this numbness relieved?

Motor symptoms:

• What movement will they be unable to do and why?
• If the injury was to happen at the level of the elbow, what would it cause? - 3
• Where will muscle wasting occur?

Answer 4

RA, Gout

Pregnancy
Obesity
Acromegaly

Thumb, index and middle fingers

Shaking the hand

Make a fist - due to weak middle and index finger flexion
Can’t flex thumb either

Impaired pronation
Weak wrist flexion
Ulnar deviation

The thenar region

Question 5

Anterior Interosseous nerve (AIN) lesions:

What nerve does it branch from?

What sign will they be unable to do?

Answer 5

Medial nerve - supplies anterior forearm

Make the ok sign - look up

Question 6

Ulnar nerve lesions:

What is compression called?

THE MAIN SYMPTOM IS MOTOR WHICH DIFFERENTIATES IT FROM MEDIAN NERVE LESIONS!

Presentation:

• What fingers are weak?
• What is the hand described as looking like?
• What test is used to test for finger adduction?

Answer 6

Cubital tunnel syndrome

Little and ring fingers

Claw-like hand

Paper between the fingers