Nerve Palsies in the Limb Flashcards
What are the myotomes for the following spinal levels?
C5,6,7 and 8
T1
L2,3,4,5
S1
C5 = elbow flexors
C6 = Wrist extensors
C7 = Elbow extensors
C8 = Finger extensors
T1 = Intrinsic hand muscles
L2 = Hip flexors
L3 = Knee extensors
L4 = Ankle dorsiflexion
L5 = Long toe extensors
S1 = Ankle plantar flexors
What are the palsies of the upper limb?
Erb’s palsies
Klumpke’s palsy
Total brachial plexus palsy
What is the cause of palsy of the axillary nerve?
Secondary to trauma
What is the cause of palsy of the radial nerve?
Radial nerve palsy secondary to compression or entrapment
What is the cause of medial nerve palsy?
Carpal tunnel syndrome
What is the cause of ulnar nerve palsy?
Cubital tunnel syndrome
Here is the brachial plexus
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What nerves are involved in erbs palsy, klumpke’s palsy and total brachial plexus palsy?
- Upper Brachial Plexus (C5,6): Erb’s Palsy - sometimes involvement of C7
- Lower Brachial Plexus (C8, T1): Klumpke’s (very rare!)
- Total Brachial Plexus (C5- T1)
What is a common cause of erbs palsy?
Dystocia - an abnormal or difficult childbirth
What is the presentation of erbs palsy?
Arm is in waiter tip position
Loss of sensation of the arm
Atrophy of deltoid, biceps, and brachialis muscles.
What causes Klumpke’s palsy?
Risk of injury to the lower brachial plexus results from traction on an abducted arm, as with an infant being pulled from the birth canal by an extended arm above the head or with someone catching themselves by a branch as they fall from a tree.
Which muscle does the musculocutaneous nerve pierce?
Pierces the coracobrachialis
(It then runs between the biceps and brachialis to supply them both
Which nerve gives supply to the elbow joint?
Musculocutaneous nerve
What does the musculocutaneous nerve continue as?
The lateral cutaneous nerve to the forearm
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
Which cord is the axillary nerve?
Posterior cord
Which part of the humerus is the axillary nerve associated with?
It wraps around the surgical neck of the humerus
Which muscles are supplied by the axillary nerve?
Deltoid
Teres minor
(also supplies the skin over the regimental badge area)
What are the nerve values for the axillary nerve?
C5 and C6
What injuries can result in axillary nerve palsy?
Shoulder dislocation
Fracture of surgical neck of humerus
Which muscles does the radial nerve supply?
The triceps
Which part of the humerus is the radial nerve assocaited with?
Radial nerve runs in the radial groove of the humerus as it passes from medial to lateral.
What are the terminal branches of the radial nerve?
Posterior interossues nerve
Superficial radial nerve
Look
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What are the two causes of radial nerve palsy?
Entrapment - fracture
Compression - falling asleep with arm over the back of a chair
Radial nerve palsy features depend on which part of the radial nerve is affected, what are the features fi the lesion is in the axilla? Arm? Forearm? wrist?
Axilla - loww of elbow extensionm wrist extension and sensory changes in the forearm and the hand
Arm - Loss of wrist extensino and sensory loss
Forearm - loss of finger extension (PIN) from previously we said that figner extension was C8
At wrist - loss of sensation (superficial radial nerve)
What are the muscles supplied by the median nerve?
Flexors of forearm (apart from the flexor carpi ulnaris and medial half of the flexor digitorum profundus)
LOAF muscles - (lumbricals, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis)
How many fingers does the median nerve supply innervation to?
3.5 radial digits
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What is the floor and the roof of the carpal tunnel
Floor = Carpal bones
Roof = Flexor retinaculum
What are the contents of the carpal tunnel?
•Contents: FDS x4, FDP x4, FPL and median nerve ie. 9 tendons and a nerve
What are the causes of carpal tunnel syndrome?
Developmental
Trauma (distal radius fracture)
Swellings (ganglion, fibroma, lipoma)
Inflammatory (rhuematoid, gout, TB, amyloid)
Swellings (ganglion, fibroma, lipoma)
Metabolic (pregnancy, mucopolysaccharidoses, hypothyroidism)
What are the features of carpal tunnel syndrome?
- Nocturnal pain and parasthesia in part or all of the median nerve distribution
- Wasting of the thenar muscles
Look feel move for carpal tunnel
•LOOK
–Thenar wasting
–Previous scars
–Deformity (previous fracture)
•FEEL
–Sensation
•MOVE
–APB power (abductor pollicis brevis)
•SPECIAL TESTS
–Tinnels
–Phalens
What are the root values of the ulnar nerve?
C8 and T1
What muslces does the ulnar nerve supply?
Medial half of FDP, FCU and all intrinsic muscles in the hand except the LOAF muscles
What digits does the ulnar nerve supply?
Supplies the ulnar 1.5 digits
Where is the cubital tunnel?
Between medial epicondyle and olecranon with fascial bands from FCU as roof
What are the clinical features of cubital tunnel syndrome?
NUmbness on ulnar side of hand and difficulty with fine tasks
What are the features of ulnar nerve palsy?
Muscle wasting - wasting of muscles on first webspace (often most marked)
Guttering
Hypothenar wasting
Ulnar claw hand
What are the features of ulnar claw hand?
Hyperextension of the MCPJ and flexion of the IPJ’s
What is froment’s test? Which muscles can be used?
Key muscles are the adductor pollicis (ulnar nerve) and the flexor pollicis longus (median nerve)
If the ulnar nerve is not working then the patient will cheat and use the flexor pollicis longus instead of the adductor
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Which nerve is associated with the sacral plexus? the lumbar plexus?
Sacral - sciatic
Lumbar - femoral
Which nerves are involved in the sciatic plexus?
•Ventral Rami of L4 to S4
Which muscles are supplied by thhe superior gluteal nerve?
Gluteus medius and minimus and TFL (tensor fascia latae)
What does the inferior gluteal nerve supply?
Gluteus maximus
What muscles are supplied by the sciatic nerve?
Posterior thigh, leg and foot muscles
What are the two divisions of the sciatic nerve?
Tibial nerve and common peroneal nerve
(supplies hamstrings in posterior compartment of thigh)
What type of accident can damage the sciatic nerve?
Posterior dislocation - common in car accidents
Which nerve wraps around the neck of the fibula?
Common peroneal nerve
What supplies the anterior compartment of the leg and the lateral compartment of the leg?
The common peroneal nerve divides into Deep Peroneal Nerve which supplies anterior compartment of leg and superficial Peroneal nerve which supplies lateral compratment
Deep peroneal nerve = anterior compartment of the leg
Superficial peroneal nerve = lateral compartment of the leg
What is the sign of peroneal nerve palsy?
Foot drop - impairment of dorsiflexion
What are the nerve vaules for the lumabr plexus?
L1 - L5
What are the main branches of the lumbar plexus?
LFCN
Femoral
Obturator
What does compression of the lateral femoral cutaneous nerve of thigh result in?
Meralgia parasthetica
Travels under the lateral border of the inguinal ligament