Nerve Palsies in Upper Limbs Flashcards
3 types of brachial plexus palsies
- Erb’s palsy (upper brachial plexus C5,6)
- Klumpke’s palsy (lower brachial plexus C8, T1)
- Total brachial palsy (C5-T1)
Which type of brachial plexus palsy is very rare
Klumpke’s palsy (lower brachial plexus C8 T1)
Cause of Erb’s palsy
- Traction of C5, 6 (+/- C7)
- Difficult birth
What does Erb’s palsy look like
- Waiter’s tip position
- Shoulder adducted + IR
- Elbow is extended + pronated
- Wrist is flexed
Causes of Klumpke’s palsy
- Traction of C8, T1
- Difficult birth
What does Klumpke’s palsy look like
Affects small muscles of hand (claw hand)
5 types of peripheral nerve palsies
- Musculocutaneous
- Axillary
- Radial
- Median
- Ulnar
From what cord does the musculocutaneous
Lateral
Define Hilton’s Law
A sensory nerve supplying a JOINT also supplies the MUSCLES moving the joint and the SKIN overlying the insertion these muscles
What area of skin + muscles does the axillary nerve innervate
- Skin over lateral arm (army badge)
- Deltoid + Teres Minor
Causes of axillary nerve palsy
- Shoulder dislocation
- Fractured surgical neck of humerus
Presentation of axillary nerve palsy
- Deltoid atrophy
- “Army badge” paresthesia
What does the radial nerve supply
- Triceps
- Extensor carpi radialis brevis
- Extensor carpi radialis longus
- Brachioradialis
What sensory nerve and motor nerve does the radial nerve divide into
- Superficial radial nerve (SRN) (sensory)
- Posterior interosseous nerve (PIN) (motor)
Causes of radial nerve palsy
- Entrapment (fracture of distal humerus)
- Compression (Crutch palsy, Saturday night palsy)
Appearance of radial nerve palsy
Depend of site of lesion
- In axilla = Loss of elbow extension, wrist extension and sensory changes in forearm + hand
- In arm = Loss of wrist extension + sensory loss
- In forearm = Loss of finger extension (PIN)
- At wrist = Loss of sensation (SRN) e.g. handcuffs
What cords make up the median nerve
Medial + Lateral cords
What does the median nerve supply
- LOAF muscles
- Flexors of forearm (bar FCU + medial half of FDP)
- Palmar aspect of thumb, index, middle + half of ring finger (sensation)
- Radial half of palm (sensation)
What makes up the floor + roof of the carpal tunnel
- Floor = Carpal bones
- Roof = Flexor retinaculum
Contents of the carpal tunnel
9 tendons + a nerve
- Flexor digitorum superficialis tendon x4
- Flexor digitorum profundus tendon x4
- Flexor pollicis longus tendon
- Median nerve
5 causes of carpal tunnel syndrome
- Developmental
- Trauma
- Swellings
- Inflammatory
- Metabolic
Trauma cause of carpal tunnel syndrome
Distal radius fracture
3 swellings causing carpal tunnel syndrome
- Ganglion
- Fibroma
- Lipoma
4 inflammatory causes of carpal tunnel syndrome
- Rheumatoid
- Gout
- TB
- Amyloid
3 metabolic cause of carpal tunnel syndrome
- Pregnancy
- Hypothyroidism
- Mucopolysaccharidoses
Symptoms of carpal tunnel syndrome
- Nocturnal pain + paraesthesia in part/all of median nerve distribution
- Wasting of the thenar muscles
3 things to LOOK for in carpal tunnel syndrome
- Thenar wasting
- Scars
- Deformity (previous fracture)
What to FEEL for in carpal tunnel syndrome
Sensation
What to MOVE in carpal tunnel syndrome
APB power
2 special tests for carpal tunnel syndrome
- Tinel’s
- Phalen manoeuvre
What cord makes up the ulnar nerve
Medial cord
What does the ulnar nerve supply
- Medial half of FDP
- FCU
- All intrinsic muscles in hand bar LOAF
- Sensation to Pinkie and ulnar half of ring finger (palmar + dorsal aspects)
Symptoms of CUBITAL tunnel syndrome
- Numbness on ulnar side of hand
- Difficulty with fine task
Wasting seen in ulnar nerve palsy
- 1st webspace (often most marked)
- Guttering
- Hypothenar wasting
Appearance of ulnar claw hand
- Hyperextension at MCPJ
- Flexion at IPJs
Describe the ulnar paradox
- A distal lesion has worse clawing than a proximal lesion
- Due to intact long flexors with a distal lesion
What two muscles does the Froment’s test
- Adductor pollicis (ulnar nerve)
- Flexor pollicis longus (median nerve)
