Flashcards in 7. Brachial plexus lesions Deck (53)
Brachial plexus - origin
Brachial plexus - structur ( divisions )
Roots --> Trunks --> Division --> Cords --> Branches before the trunks C5-C7 root are giving rise to long thoracic nerve
Branchial plexus - roots
Branchial plexus - trunks ( types and origin )
1. upper ( C5-C6)
2. Middle ( C7)
3. Lower ( C8-T1)
Brachial plexus - division
- from upper to middle trunk
- from middle to upper
- from lower to middle
Branchial plexus - cords
- middle trunk is becoming posterior and the divide to axillary and radial nerve
- upper trunk becomes lateral
-lower trunk becomes medial
posterior ( middle ) trank is divided to
1. axillary nerve
2. radial nerver
Branchial plexus - branches
- together lower and upper trunks give rise to median nerve
- lower trunk is becoming ulnar nerve
-upper nerve is becoming musculocutaneous nerve
Erb palsy is also called
Erb palsy ( waiter's tip ) injury
traction or tear of upper trunk
upper trunk origin ( roots )
causes of Erb palsy ( waier's tip )
infants - lateral traction of neck during delivery
adults - trauma
causes of Erb palsy - muscle deficit
4. biceps branchi
causes of Erb palsy - functional deficit presentation ( and muscle responsible )
1. abduction ( arms hangs by side ) ( deltoid, supraspinatus )
2. lateral rotation ( arm medially rotated ) ( ingraspinatus )
3. flexion and sunipation ( arm extended and pronated ) ( bicepts branchi )
Klumpke palsy is also called
klumpke palsy ( Claw hand) - injury
tranction or tear of lower trunk
lower trunk roots
causes of Klumpke palsy ( Claw hand )
infants - upward force on arm during delivery adults - trauma
Klumpke palsy ( Claw hand ) - adults trauma example
grabbing a tree branch to break a fall
Klumpke palsy ( Claw hand ) - muscle deficits
intrinsic hand muscles
Klumpke palsy ( claw hand ) - presentation
total claw hand
normal action of hand lumbricals
flex MCP and extend DIP and PIP joints
muscle deficit of Klumpke palsy are the same as the ... syndrome
throracic outlet syndrome
thoracic outlet syndrome - injury
compression of lower trunk AND subclavian vessels
causes of thoracic outlet
1. cervical rib
2. pancoast tumor
thoracic outlet syndrome - muscle deficit
intrinsic hand muscles
muscle defiit of thoracic outlet syndrome are the same with
Klumpke palsy ( Claw hand)
thoracic outlet syndrome - presentation
- atrophy of intrinsic hand muscles
- ischemia, pain and edema ( due to vascular compression )
Winged scapula - injury
lesion of long thoracic nerve
long thoracic nerve - origin
C5-C6-C7 ( before the formation of the trunks )
causes of winged scapula
1. axillary node dissection after mastectomy
2. stab wound
Winged scapula - muscle deficit
Winged scapula - functional deficit ( presentation )
problem on serratus anterior --> inability to abchor scapula to thoracic cage --> cannot abduct arm above the horizontal position
hand at rest
balance between the extrinsic flexors and externors as well as the instinct muscles of the hand ( particularly the lumbrical muscles )
Distortions of the hand - clawing seen best in
DISTAL lesions of median or ulnar nervers
clawing appearance of the hand - pathophysiology
DISTAL lesions of median or ulnar nerves --> remaining extrinsic flexors of digits exaggerate the loss of the lumbricals the loss of the lumbricals --> extension of MCP, flexion of DIP and PIP
claw hand - muscle action
extension of MCP, flexion of DIP and PIP
• Over months, a lung cancer patient develops atrophy, pain, and edema in his right hand. Where is his tumor most likely invading?
Compressing the lower trunk of the brachial plexus and the subclavian vessels (the patient likely has a right-sided Pancoast tumor)
• A falling climber grabs a tree branch as he falls. Afterward, he can no longer flex his hand's MCP joints. What nerve roots were injured?
C8–T1 (he likely suffered traction of or tore the lower brachial plexus trunk as he fell, suggestive of a Klumpke palsy)
• A man has problems abducting and laterally rotating his shoulders, and flexing/supinating at his elbows. Where is the nerve injury?
C5–C6, with deltoid, supraspinatus, infraspinatus, & biceps brachii deficits due to upper brachial trunk lesion (Erb palsy = "Erb"-er trunk)
• A patient presents with a waiter's-tip deformity after being thrown from a motorcycle. What cervical roots are now impaired?
C5, C6 (upper trunk of brachial plexus) (known as Erb palsy)
• An adult has his left arm by his side, shoulders internally rotated, arms extended and pronated. He cannot change this position. Diagnosis?
This is an Erb palsy (C57#8211;C6 injury) (also known as a waiter's tip)
• A patient presents with wrist drop after getting drunk and sleeping on a couch all of Saturday night. What nerve was most likely injured?
The radial nerve (this is a classic Saturday night–palsy presentation)
• Your attending tells you to examine a patient who suffered damage to his musculocutaneous nerve. What deficits do you uncover on exam?
Difficulty flexing the elbow, variable sensory loss over the arm
• A lesion to the lower trunk of the brachial plexus produces what deficit? Describe the expected findings on exam.
Impaired MCP joint flexion and DIP/PIP joint extension from impaired lumbrical, interosseous, thenar, and hypothenar muscles (Klumpke palsy)
• Claw hand (Klumpke palsy) can result from damage to what part of the brachial plexus?
Lower trunk (C8–T1 nerve roots)
• A newborn's delivery was complicated by excessive lateral neck traction. Now her arm hangs limply and is medially rotated. What happened?
She developed an Erb palsy due to traction on or damage to the upper trunk of the brachial plexus (C5–C6 nerve roots)
• A man has atrophy of his lumbricals with ischemia, pain, and edema from vascular compression. He has supernumerary cervical ribs. Diagnosis?
Thoracic outlet syndrome secondary to the supernumerary cervical rib causing compression
• A conman is stabbed. He cannot abduct his arm past 90° and his scapulas appear asymmetric. What muscle is impaired?
Serratus anterior (causing a winged scapula due to a long thoracic nerve injury)
• A man has posterior cord damage from trauma. Two nerves exiting from this cord are impaired. What two major findings will you see on exam?
Deltoid paralysis (due to axillary nerve impairment) and wrist drop (due to radial nerve impairment)
• A trauma patient has proximal median nerve damage. When he recovers, you examine his ipsilateral hand. What motor deficits will you uncover?
Decreased thumb function and a Pope's-blessing deformity
• A trauma patient has proximal ulnar nerve damage. When he recovers, you examine his ipsilateral hand. What motor deficits will you uncover?
Decreased function of the intrinsic muscles of the hand with a claw-hand deformity