FN: Other Nerve Injuries

Question 1

Radial Nerve Lesions (C5-T1) Low lesions:

Answer 1

Posterior interosseous nerve

Question 2

Radial Nerve Lesions (C5-T1) Low lesions: site

Answer 2

Fracture around elbow or forearm e.g. fracture head of the radius

Question 3

Radial Nerve Lesions (C5-T1) Low lesions: loss

Answer 3

Loss of extension of CMC joints (fnger drop)

No sensory loss

Question 4

Radial Nerve Lesions (C5-T1) high lesions site

Answer 4

Fracture of shaft of humerus where N. is in radial groove

Question 5

Radial Nerve Lesions (C5-T1) high lesions presentation

Answer 5

Wrist drop
Loss of sensation to dorsum of thumb root (snuff box)
Triceps functions normally

Question 6

Radial Nerve Lesions (C5-T1) high lesions very high lesions site

Answer 6

Axilla e.g. crutches or SAturday night palsy

Question 7

Radial Nerve Lesions (C5-T1) high lesions very high lesions presentation

Answer 7

Paralysis of triceps and wrist drop

Question 8

Ulnar Nerve (C8-T1) damage site

Answer 8

Elbow: cubital tunnel
Wrist: in Guyons Canal

Question 9

Ulnar Nerve (C8-T1) effects

Answer 9

• Intrinsic hand muscle paralysis - claw hand
• Ulnar paradox, lesion at elbow has less clawing as FDP is paralysed, decreasing flexion at 4th/5th digits
• Weakness of finger ab/abduction (interossei)
• Sensory loss over little finger

Question 10

Ulnar Nerve (C8-T1) Tests

Answer 10

• Cant cross fingers for luck
• Forments sign: flexion of thumb IPJ when trying to hold onto paper held between thumb and finger - indicates weak adductor pollicis

Question 11

Median Nerve (C5-T1) injury above the antecubital fossa

Answer 11

• Cant flex index finger IPJs (e.g. on clasping hands)
• Cant flex terminal thumb phalanx (FPL)
• Loss of sensation in median distribution

Question 12

Median Nerve (C5-T1) injury at the wrist

Answer 12

• Typically affects abductor pollicis brevis

Question 13

Median Nerve (C5-T1) injury types

Answer 13

• injury above the antecubital fossa
• injury at the wrist
• Carpal tunnel syndrome