231. Peripheral Neuropathies Upper Limb Flashcards
Upper Brachial Plexus Injury
Name, Nerves injured, Adult/Newborn Causes
Erb’s Palsy
Traction/Tear of Upper Trunk (c5/c6)
adult: blow to shoulder causing excessive separation of neck/shoulder
newborn: pulling on head with arm caught during delivery
Erb’s Palsy Effects
Paralysis of Proximal Limb Muscles - C5/C6 dermatomes
“Waiter’s Tip” - arm extended (no bicep), adducted/medially rotated (no deltoid/rotator cuffs), forearm extended (no bicep),
Weak to extend wrist (part of wrist extensors from C6)
Anaesthesia of C5/C6 dermatomes (lateral arm, forearm, hand)
Lower Brachial Plexus Injury
Name, Nerves affected, Causes
Klumpke’s Palsy
Traction/tear of lower trunk (C8/T1 - medial cord)
Newborn: forceful upward pull of shoulder during birth
Adult: grasping onto something to break fall
Thoracic outlet syndrome: cervical rib/fibrous band compresses lower trunk
Effects of Klumpke’s Palsy
Paralysis of distal limb muscles
Klumpke’s Total Claw Hand (affects intrinsic hand muscles from median and ulnar nerve)
-MCP extended, PIP/DIP flexed, thenar/hypothenar paralysis (loss of lumbricals)
Anaesthesia of C8/T1 dermatome (medial hand (4-5 digit), forearm, arm
Common Findings to Lesions of Median Nerve
- Ape hand: extended/adducted thumb (loss of thenar muscles)
- Anaesthesia of dorsal/palmar 2nd-half of 4th digit + palmar thumb
Proximal lesion of median nerve
Cause and Effects
Cause: fractures of humerus above epicondyles can compress/cut median nerve
Effect: “Pope’s Blessing/Hand of Benediction” when pt asked to FLEX
cannot flex 2/3 digit (loss of FDS/lateral FDP)
Distal Lesion of Median Nerve
cause and effect
C: Carpal Tunnel Syndrome
E: Median claw hand of digits 2/3
Pt can NOT flex MCP/Extend DIP/PIP (loss of lateral lumbricals)
Common Findings to Ulnar Nerve Lesions
- Loss of intrinsic hand abduction/adduction (DAB/PAD) + atrophy of intermetacarpal spaces
- Loss of thumb adduction (adductor pollicis)
- DIP/PIP flexion in 4/5 digit (loss of 3/4 lumbricals)
- Anaesthesia of dorsal/palmar medial hand (4/5 digit)
Proximal Lesion to Ulnar Nerve
causes and effect
C: Fractures to medial epicondyle cut nerve, nerve compression in ulnar groove of humerus
E: Paralysis of forearm + hand muscles
- Mild claw hand of 4/5 digits: DIP extension (loss of Medial FDP), MCP extension/PIP flexion (loss of medial lumbricals)
- Wrist flexion weakness (loss of F. carpi ulnaris)
Distal Lesion of Ulnar Nerve
causes and effect
C: nerve compression in tunnel of Guyon, fracture of hook of hamate (fall on outstretched hand)
E: Ulnar Claw Hand of digits 4/5: MCP extension, PIP/DIP flexion (loss of medial lumbricals)
Resembles Pope’s Blessing but occurs when patient asked to EXTEND fingers
Causes of Radial Nerve Injury
Fractures of Humeral Shaft
Compression of Nerve in Radial Groove (saturday night palsy, Honeymoon palsy, Crutch palsy)
Effects of Radial Nerve Injury
- Wrist Drop (no wrist extensors)
- MCP flexion (no MCP extensors)
Rare chicken wing deformity if lose triceps (elbow flexion)
Anaesthesia of radial half of dorsal hand
Axillary Nerve injury (cause and effects)
Cause: cut from fracture of humeral surgical neck, stretched from shoulder dislocation
Effect: Shoulder adducted, weak to lateral rotate (no deltoid/teres minor), atrophy and anesthesia of lateral shoulder
Long Thoracic Nerve Injury (Cause and Effects)
C: injured during surgery (mastectomy or thoracic surgery)
E: paralysis of serratus anterior - Winging of scapula (No sensory loss)
Musculocutaneous Nerve Injury (Cause/Effect)
C: penetrating wounds to axilla
E: severe weakness of forearm flexion (lose biceps/brachialis)
weakness of supination (lose bicapes)
Weakness of arm flexion (lose coracobrachialis, biceps)
anaesthesia of lateral forearm (lateral cutaneous branch)
