Brachial Plexus: Everything You Would Never Want To Know Otherwise

Front 1

There are three trunks distributing to 5 major nerves

Back 1

truth

Front 2

C5-C6 is the ________ trunk and its terminal nerves are the ___________________ nerve.

Back 2

upper; musculocutaneous

Front 3

C7 is the ____________ trunk and it has three terminal nerves

Back 3

middle trunk
axillary nerve (posterior cord)
radial nerve (posterior cord)
median nerve

Front 4

C8-T1 is the ____________trunk and its terminal nerve is the ___________ nerve

Back 4

lower; ulnar

Front 5

Forceful separation of the neck and shoulder often seen in deliveries, motorcycle accidents, and football tackles. The arm hangs in medial rotation (waiters tip)

Back 5

Upper brachial plexus injury (Erbs palsy)
limb hangs by side (paralysis of abductors)
medially rotated (paralysis of lateral rotators)
forearm is pronated (loss of biceps)

Front 6

What are the specific nerves damaged in Erb's palsy?

Back 6

musculocutaneous - loss of supination
axillary nerve - arm is ADDucted
suprascapular nerve (C5-C6) - infraspinatous externally rotates
axillary nerve again - (C5) - teres minor externally rotates

Front 7

A posterior cord injury is damage to which part of the BC?

Back 7

Wrist drop or posterior cord injury
Axially and radial nerve damage
cannot extend wrist or extend fingers at MCP joint, forearm is supinated (no brachioradialis or supinator mm)

Front 8

A lower brachial plexus injury is damage to which part of the BC?

Back 8

Lower cord which makes up the ulnar nerve

Front 9

A proximal and lower lesion to the ulnar nerve (C8-T1 root) will present how?

Back 9

proximal - fracture of the medial epicondyle of the humerus, fingers in medial flexion, radial deviation upon wrist flexion
Distal - fracture of hook of hamate (falling onto an outstretched hand), ulnar claw if fingers are streightened, Pope's blessing at rest

Front 10

What is the damage in the "ulnar claw" aka Pope's blessing?

Back 10

DISTAL ulnar nerve lesion
loss of medial lumbrical function: 4th and 5th digits are clawed

Front 11

Pt presents with second and third digits clawed. Where is the lesion and what mm are affected?

Back 11

distal median nerve lesion (after C5-C7 branches off)
Loss of lateral lumbriclal function

Front 12

Pt presents with the inability to ABDuct the thumb. Where is the lesion and what nerves are affected?

Back 12

proximal median nerve lesion; loss of opponens pollicies mm
"ape hand"

Front 13

Pt presents with hand that is is the claw position, he appears agressive shouting "I'm the claw man, I've come to squeeze your hooters!" where is the lesion and what mm are affected?

Back 13

Lesion of the lower trunk (C8-T1)-->Loss of all lumbricals
Forearm finger flexors-->part of the median nerve with C5-C7
Loss of finger extensors-->radial nerve

Front 14

pt presents with wrist drop and loss of triceps reflex. Claims he cannot feel sensation on his posterior arm and the dorsum of his hand

Back 14

Radial nerve lesion

Front 15

pt claims he cannot flex his elbow, or carry soup. Biceps reflex is diminished and he cannot feel sensation on the posterior forearm

Back 15

Musculocutaneous nerve lesion

Front 16

Same asshole with clawhand comes back because he cannot feel sensation where?

Back 16

1.5 digits of 4 and 5