Nerve palsies Flashcards
Peripheral nerves in upper limb
musulocutaneous median axillary radial ulnar
Peripheral nerves in lower limb
LFCN
sciatic
common peroneal
femoral
Spinal level and myotomes
C5.6.7.8.T1
L2,3,4,5S1
elbow flexors wrist extensors elbow extensors finger extensors intrinsic muscles of the hand
hip flexors knee extensors ankle dorsiflexors long toe extensors plantarflexors
3 types of nerve palsies associated with brachial plexus
Erb’s
Klumpke’s
total brachial plexus
Erb’s palsy spinal level
C5,6
Klumpke’s palsy spinal level
C8,T1
Erb’s palsy
common, traction of C5/6 in labour
appearance of Erb’s palsy
waiter’s tip –> shoulder adducted and internal rotation, elbow extended and pronated wrist flexed
Is Erb’s or Klumpke’s palsy more common?
erb
Causes and appearance of klumpke’s palsy
falling out of tree, delivered hand first
small muscles of hand - claw hand
spinal nerve roots of MCN nerve
C5,6,7
MCN cord
lateral
What muscle does MCN pierce?
coracobrachialis
What 2 muscles does MCN run inferiorly between and supply?
biceps brachii
brachialis
What joint does MCN supply?
elbow
How does MCN terminate?
as lateral cutaneous nerve to forearm
Hiltons law
a sensory nerve supplying a joint also supplies muscles moving joint and skin overlying muscle insertions
axillary nerve cord
posterior
What does the axillary nerve wrap around?
surgical neck of humerus
what muscles does the axillary nerve supply?
deltoid and teres minor
what skin does axillary nerve supply?
over lateral arm - regimental badge area
When can the axillary nerve be damaged and what are the signs?
shoulder dislocation and fracture of the surgical neck of the humerus
deltoid atrophy
Radial nerve spinal level
C5-T1
Axillary nerve spinal level
C5.6
Radial nerve cord
posterior
What muscles does the radial nerve supply?
triceps, brachioradialis, ECRB,ECRL
What groove does the radial nerve run in?
radial groove of humerus going from the medial to lateral side
What does the radial nerve divide into?
posterior interosseous nerve
superficial radial nerve
PIN supplies - motor or sensory?
motor
SRN supplies - motor or sensory?
sensory
2 causes of radial nerve palsy
entrapment eg fracture of humerus
compression eg Saturday night palsy
radial nerve palsy in axilla
loss of elbow and wrist extension, sensory changes in forearm and hand
radial nerve palsy in arm
loss of wrist extension and sensory loss
Radial nerve palsy in forearm
loss of finger extension - PIN
Radial nerve palsy in wrist
sensory loss - SRN eg handcuff
median nerve spinal level
C5-T1
median nerve cords
median and lateral
Median nerve supplies…
flexors of forearm (bar FCU and medial FDP), LOAF muscles
LOAF muscles
lateral 2 lumbricals, opponens pollicus, abductor pollicus brevis and flexor pollicus brevis (thenar)
median nerve sensation
radial 3.5 digits
floor, roof and contents of carpal tunnel
floor - carpal bones
roof - flexor retinaculum
contents - median nerve, 4 xFDS, 4X FDP and FPL
Causes of carpal tunnel syndrome
developmental swelling eg ganglion trauma eg distal radius fracture inflammatory eg rheumatoid, gout, TB metabolic eg pregnancy
symptoms and signs of carpal tunnel syndrome
nocturnal pain and paraesthesia in part or all of median nerve distribution
wasting of thenar muscles
2 special tests for carpal tunnel syndrome
tinnels and phalens
Treating carpal tunnel syndrome
release flexor retinaculum
Ulnar nerve spinal level
C8, T1
ulnar nerve cord
medial
Does ulnar nerve have branches in arm?
no
How does ulnar nerve enter forearm?
between 2 heads of FCU
Ulnar nerve supplies
medial half of FDP, FCU and all intrinsic hand muscles but not LOAF
ulnar 1.5 digits sensation
Where is the cubital tunnel?
between medial epicondyle and olecranon with FCU as roof
symptoms of cubital tunnel syndrome
numb on ulnar side of hand and difficult with fine tasks
wasted muscles in ulnar nerve palsy
1st webspace
guttering
hypothenar
ulnar claw hand
hyperextended MCPJ and flexed IPJ’s
ulnar paradox
distal lesions worse clawing due to intact long flexors`
Froment’s test
ulnar nerve not working so cheat and use FPL supplied by median nerve instead of AP
sacral plexus nerves
sciatic –> common peroneal and tibial
Lumbar plexus nerve
femoral
sacral plexus level
ventral rami of L4-S4
superior gluteal nerve supplies
gluteus medius, minimus and TFL
inferior gluteal nerve supplies
gluteus maximus
sciatic nerve supplies
hamstrings in post compartment of thigh
What does the common peroneal nerve wrap around?
neck of fibula
what does common peroneal nerve divide into?
deep and superficial peroneal nerve
deep peroneal nerve supplies
anterior compartment of leg
superficial peroneal nerve supplies
lateral compartment of leg
common peroneal nerve palsy
foot drop as impairs dorsiflexion
Lumbar plexus roots
L1-5
main branches of lumbar plexus
LFCN, femoral and obturator
meralgia parasthetica
altered sensation and pain in lateral thigh as LFCN compressed as it travels under lateral border of inguinal ligament