Nerve Palsies of the Limbs Flashcards
how can nerves be damaged?
trapped
injured
compressed
myotome: C5
elbow flexors
myotome: C6
wrist extensors
myotome: C7
elbo extensord
myotome: C8
finger extensors
myotome: T1
intrinsic hand muscles
myotome: L2
hip flexors
myotome: L3
knee extensors
myotome: L4
ankle dorsiflexors
myotome: L5
long toe extensors
myotome: S1
ankle plantar flexors
brachial plexus injuries result in:
Erb’s palsy
Klumpke’s palsy
total brachial plexus
cause of nerve palsy: axillary
secondary to trauma
cause of nerve palsy: radial
secondary to compression or entrapment
cause of nerve palsy: medial
carpal tunnel syndrome
cause of nerve palsy: ulnar
cubital tunnel syndrome
draw the brachial plexus
see notes
what does C5,6 brachial plexus injury result in?
Erb’s palsy
what does C8-T1 brachial plexus injury result in?
klumpke’s palsy
describe an erb’s palsy
waiter’s tip - shoulder adducted and IR, elbow extended and pronated, wrist flexed
describe a Klumpke’s palsy
small muscles of hand - claw hand
nerve roots of musculocutaneous nerve
C5,6,7
what cord does the musculocutaneous nerve come from?
lateral
describe the course of the musculocutaneous nerve
pierces coracobrachialis, then runs inferiorly between biceps and brachialis
what does the musculocutaneous nerve terminate as?
lateral cutaneous nerve of the forarms
what does the musculocutaneous nerve supply?
anterior capsule of elbow
BBC and skin overlying the insertions of these muscles
what is Hilton’s law?
a sensory nerve supplying a joint also supplies the muscles moving the joint and the skin overlying the insertions of these muscles
nerve roots of the axillary nerve
C5,6
what cord does the axillary nerve come from?
posterior
fracture of what part of the humerus may cause injury to the axillary nerve?
surgical neck
what does the axillary nerve supply?
deltoid
teres mino
skin over lateral arm
injury to the axillary nerve results in atrophu of what muscle?
deltoid
nerve roots of the radial nerve
C5,6,7,8,T1
what cord does the radial nerve come from?
posterior
where does the radial nerve rum?
radial groove of humerus as it passes from edial to lateral
what does the radial nerve supply?
triceps
brachioradialis
ECRL
ECRB
radial nerve palsy: axilla
loss of elbow extension, wrist extension, and sensory changes in forearm and hand
radial nerve palsy: arm
loss of wrist extension and sensory loss
radial nerve palsy: forearm
loss of finger extension (PIN)
radial nerve palsy: wrist
loss of sensation (SRN) e.g. handcuffs
nerve roots of medial nerve
C5,6,7,8,T1
what cord does the median nerve come from?
medial and lateral
what does the median nerve supply
flexors of the forearm except FCU and medial half of FDP
LOAF - lat 2 lumbricals, APB, OP, FDB
sensation to radial 3.5 digits
floor of carpal tunnel
carpal bones
roof of carpal tunnel
flexor retinaculum
contents of carpal tunnel
FDS x 4
FDP x 4
FPL
median nerve
causes of carpal tunnel syndrome
developmental trauma distal radius fracture ganglion fibroma lipoma inflammatory - rheumatoid, Gout, TB, amyloid metabolic - pregnancy, mucopolysaccharidoses, hypothyroidism
signs and symptoms of carpal tunnel syndrome
nocturnal pain
parasethesia
in part or all of the median nerve distribution
wasting of the thenar muscles
tests for carpal tunnel syndrome
tinnels
phalen’s
nerve roots of the ulnar nerve
C8, T1
what cord does the ulnar nerve come from?
medial cord
how does the ulnar nerve enter the forearm
between the two ends of FCU
what does the ulnar nerve supply?
medial half of FDP
FCU
intrinsic muscles of hand except LOAF
sensation to ulnar 1.5 digits
where is the cubital tunnel found?
between medial epicondyle and olecranon with fascial bands from FCU as roof
symptoms of cubital tunnel syndrome
• Patient has numbness on ulnar side of hand and difficulty with fine tasks • Wasting of muscles o 1st webspace o Guttering o Hypothenar wasting
describe ulnar claw hand
hyperextension at MCPJ, flexion at IPJs
what is the ulnar paradox?
a distal lesion has worse clawing than a proximal lesion due to intact long flexors
the sacral plexus is formed from the ventral rami of?
L4-S4
what does the superior gluteal nerve supply?
gluteus medius and minimus
TFL
what does the inferior gluteal nerve supply?
gluteus maximus
nerve roots of sciatic nerve?
L4,5,S1,2,3
what does the sciatic nerve divide into?
tibial and common peroneal nerve
what does the sciatic nerve supply?
hamstring muscles in posterior comparment of thigh
where does the common peroneal nerve wrap around?
neck of fibula
what nerve supplies the anterior leg compartment?
deep peroneal
what nerve supplies the lateral leg compartment?
superficial peroneal
name the main branches of the lumbar lexus
LFCN
femoral
obturator
what is meralgia parasthetica?
• Altered sensation and pain in the lateral thigh
• Compression of lateral femoral cutaneous nerve of
thigh as it travels under lateral border of inguinal
ligament