Usmle Brachial Plexus

Front 1

label

Back 1

labeled

Front 2

What nerve is injured?
How would you injury this nerve?
What physical exam findings would the patient have?

Back 2

Long Thoracic Nerve (C5,6,7) Serratus Anterior muscle
can be injured in mastectomy
PE: winged scapula (when patient pushes hands against wall the scapula protrudes posteriorly)

Front 3

This event (sudden upward stretching on the arm at the shoulder) injures what part of the brachial plexus?
What are the consequences of this injury?

Back 3

Lower trunk injury

This trunk carries nerves from the C8, T1 spinal levels that ultimately form the median & ulnar nerves

These nerves innervate all the intrinsic muscles of the hand

results in hand clumsiness or palaysis (klumpke's palsy/ thoracic outlet syndrome)

atrophy of thenar & hypothenar eminences, atrophy of interosseous muscles, sensory deficits on medial side of forearm & hand, disappearnce of the radial pulse upon moving the head toward the ipsilateral side

Front 4

What part of the brachial plexus is injured?

What are the consequences?

Back 4

inferior trunk injury (C8, T1, median/ ulnar nerves, subclavian artery can also be compressed)

Thoracic outlet syndrome/ Klumpkes palsy
Lower trunk injury

atrophy of thenar & hypothenar eminences, atrophy of interosseous muscles, sensory deficits on medial side of forearm & hand, disappearnce of the radial pulse upon moving the head toward the ipsilateral side

Front 5

This injures what part of the brachial plexus?
What S/S result?

Back 5

Upper Trunk injury (C5, C6 roots - Axillary n, Supraspinatus n, Musculocutaneous n)

S/S: Erb's Palsy/ Waiter's tip
Limb hangs by side, medially rotated & pronated

Front 6

What S/S result from this injury?
How would this injury occur?

Back 6

Tear of UPPER trunk, any situation that stretches neck - ie motorcycle injury, pulling baby by head during birth
S/S: Erb's palsy - waiter's tip

Front 7

What part of the brachial plexus is injured?
What S/S result?

Back 7

UPPER trunk (C5, C6 - axillary, musculocutaneous, supraspinatus)

Erb's Palsy - "Waiter's Tip"
Limb hangs by side, medially rotated & in pronation

Front 8

What part of the brachial plexus was injured?

Back 8

Upper trunk

Front 9

This claw hand demonstrates a patient that has difficulty making a fist & spreading his fingers

What nerve is damaged?
How do damage this nerve?

Back 9

Ulnar nerve

medial half of flexor digitorum profundus is denervated + loss of interosseus muscles (cannot abduct or adduct fingers) - interosseus atrophy can be seen too

injury of the ulnar nerve at the medial epicondyle

Front 10

Explain this sensory loss - what nerve is damaged? What is a likely cause of damage?

Back 10

Ulnar nerve

"Handle Bar Palsy" - hook of hamate compresses ulnar nerve

Front 11

what nerve is at risk of injury with a fracture of the medial epicondyle?

Back 11

ulnar nerve

Front 12

What nerve is most at risk with a fracture of the surgical neck of the humerus?

Back 12

axillary nerve (deltoid muscle)

Front 13

What nerve is most at risk with a fracture of the shaft of the humerus?

Back 13

Radial nerve

Front 14

What nerve is most at risk of an injury to the supracondyle of the humerus?

Back 14

median nerve

Front 15

what nerve is most likely injured from medial supracondylar region?

Back 15

median nerve