Nerve lesions in arm

Question 1

Axillary nerve lesion

Answer 1

inability to abduct partially abducted arm beyond first 15 degrees

no sensory over lower deltoid

teres minor atrophies

Question 2

Musculocutaneous nerve lesion

Answer 2

loss of biceps reflex

loss of flexion at elbow

weak supination

Question 3

Radial nerve lesion

Answer 3

extensor at all arm, wrist and finger joints below shoulder

forearm supination

thumb adduction in plane of palm

loss of triceps and radial reflex

wrist drop

Question 4

Median nerve lesion

Answer 4

loss of flexion, weak pronation

loss of thenar mm (can still adduct and extend)

preachers/orator’s hand: index finger, thumb, and middle finger (partially) not able to flex

ape (simian) hand: thumb extended and adducted, fingers extended

Question 5

Ulnar nerve lesion

Answer 5

loss of abduction and adduction of fingers

loss adduction of thumb

weak wrist flexion and adduction

claw hand: extension of distal fingers 4 and 5, flexion of distal fingers 2 and 3

Question 6

Erb-Duchenne palsy

Answer 6

tearing of C5-C6 roots in motorcycle accidents, birthing, etc.

Question 7

Klumpke’s paralysis

Answer 7

occurs when there is an injury to C8-T1 roots (very rare)

Question 8

C5 lesion

Answer 8

weakness: deltoid, infraspinatus, biceps

reflex decreased: biceps, pectoralis

sensory abnormality: shoulder, upper lateral arm

disc involved: C4-C5

Question 9

C6 lesion

Answer 9

weakness: wrist extensors, biceps

reflex decreased: biceps, brachioradialis

sensory abnormality: first and second fingers, lateral forearm

disc involved: C5-C6

Question 10

C7 lesion

Answer 10

weakness: triceps

reflex decreased: triceps

sensory abnormality: 3rd finger

disc involved: C6-C7