Nerve palsies in the limbs Flashcards
How do you remember the posterior lower limb dermatomes?
Stand on S1
Sleep on S2
Sit on S3
Shit on S4
What is Hilton’s law?
The nerves crossing a joint supply the muscles acting on the joint and the joint itself
(May supply 2 joints so disease in one may result in pain for both)
Which nerves supply the hip?
Obturator
Femoral
Lateral femoral cutaneous
What is a myotome?
Group of muscles supplied by one segment of spinal cord
Describe Erb-Duchenne paralysis.
Arm adducted
Forearm extended and pronated
Wrist flexed
Caused by C5,C6 damage
Which muscles do the axillary nerve supply?
Deltoid
Teres Minor
Skin over lateral arm
Why is the axillary nerve more at risk than others?
Wrap around surgical neck of humerus
Stretched in dislocation
May be damaged by fractured neck of humerus
Commonly affected in shoulder injury
Which nerve supplies the triceps?
Radial
How may palsy arise in the radial nerve?
Associated with fractures
Entrapment
Caught or transected in fractures and compound fractures
Compression e.g falling asleep with arm over chair
What does the median nerve supply?
Forearm flexors
Medial half of FDP
Sensation for radial 3.5 digits
How does motor deficit of the median nerve present?
Thenar wasting
Pointing finger
How would a brachial plexus lesion affect the arm?
Erb-Duchenne paralysis
How might a brachial plexus lesion affect the hand?
Clawed
Klumpke’s paralysis
How would motor deficit of the axillary nerve present?
Affects deltoid
Loss of shoulder abduction
How would sensory deficit of axillary nerve present?
Affects badge area
How might motor deficit of the radial nerve present?
Affects extensors
Causes wrist drop
How might a sensory deficit of the radial nerve present?
Affects 1st web space dorsally
Where would a sensory deficit of the median nerve affect?
Palmar aspect of thumb
How would a motor deficit of the ulnar nerve present?
Claw hand
Hypothenar and 1st dorsal interosseous wasting
Where might a sensory deficit of the ulnar nerve affect?
Pinky finger
Where does the lumbar plexus lie?
Surface of quadratus lumborum and within psoas muscle
Where are the roots of the femoral nerve?
L2-L4
Which nerve supplies the quadriceps muscle in the thigh?
Femoral
Which nerve provides sensory innervation to lateral aspect of thigh?
Lateral femoral cutaneous nerve
What is the largest nerve in the body?
Sciatic nerve
Which muscles are supplied by the sciatic nerve?
Hamstring
Part of adductor magnus
All lower leg and foot muscle in terminal branches
When is the sciatic nerve at risk?
Posterior dislocation of hip
IM injections during surgery
Where are the roots for the sciatic nerve?
L4-S3
Which nerve deficit causes foot drop and slapping gait?
Common fibular nerve
Small lateral branch of sciatic nerve which passes around neck of fibula
Most commonly injured lower limb nerve
Which nerve supplies sensory innervation to most of the dorsum of the foot?
Superficial peroneal nerve (SPN)
