Nerve Palsies in the Limbs Flashcards
1
Q
Describe the brachial plexus?
A
From spinal roots C5-T1 > upper, middle and lower trunk > anterior/posterior divisions > medial/lateral cords > branches
2
Q
Brachial lesions are common in what?
A
Childbirth
Upwards traction (such as fall onto side of neck - upper cord damage)
Downwards traction - lower cord damage
3
Q
Damage to what spinal nerves is considered upper cord damage?
A
C5, C6
4
Q
What muscles are supplied by the upper cords (C5, C6)?
A
Deltoid
Shoulder muscles
Brachialis
Biceps
5
Q
What kind of paralysis does upper cord damage cause?
A
- Causes Erb-Duchenne paralysis (arm “porters tip”)
- Arm adducted, elbow extended, forearm pronated, wrist flexed
6
Q
Describe Erb-Duchenne paralysis?
A
- Causes Erb-Duchenne paralysis (arm “porters tip”)
- Arm adducted, elbow extended, forearm pronated, wrist flexed
7
Q
Damage to what spinal nerve is lower cord damage?
A
T1
8
Q
What paralysis does lower cord damage cause?
A
Klumpke’s palsy
9
Q
Axillary nerve is formed from what spinal nerves?
A
C5, C6
10
Q
What cord forms axillary nerve?
A
Posterior cord
11
Q
What does the axillary nerve supply?
A
- Wraps around surgical neck of humerus supplying deltoid and teres minor, also regimental badge area of skin
12
Q
Damage to axillary nerve causes what paralysis?
A
- Axillary nerve palsy
- Caused in shoulder dislocation or fracture of surgical neck of humerus
- Presentation
- Lack of sensation in badge area
- Deltoid atrophy
13
Q
What is the presentation of axillary nerve palsy?
A
- Lack of sensation in badge area
- Deltoid atrophy
14
Q
What often causes axillary nerve palsy?
A
- Caused in shoulder dislocation or fracture of surgical neck of humerus
15
Q
Radial nerve is formed from what spinal nerves?
A
C5, C6, C7, C8, T1
16
Q
Radial nerve comes from what cord?
A
Posterior cord
17
Q
What does the radial nerve supply?
A
- Tricep brachii
- Supplies BCR, ECRL and ECRB before dividing into PIN (motor) and SRN (sensory) branches
18
Q
Describe the course of the radial nerve?
A
- Runs in radial groove of humerus as it passes from medial to lateral
19
Q
Radial nerve damage causes what paralysis?
A
- Radial nerve palsy
- Occurs in entrapment (maybe in radial fracture) or compression (such as due to Saturday night palsy)
- Presentation depends on site of lesion
- In axilla – lose of elbow extension, wrist extension and sensory changes in forearm and hand
- In arm – loss of wrist extension and sensory loss
- In forearm – loss of finger extension (PIN)
- At wrist – loss of sensation (SRN)
20
Q
What is the presentation of radial nerve palsy?
A
- In axilla – lose of elbow extension, wrist extension and sensory changes in forearm and hand
- In arm – loss of wrist extension and sensory loss
- In forearm – loss of finger extension (PIN)
- At wrist – loss of sensation (SRN)
21
Q
What often causes radial nerve palsy?
A
- Occurs in entrapment (maybe in radial fracture) or compression (such as due to Saturday night palsy)
22
Q
What nerve supplies snesation to this area?
A
Radial nerve
23
Q
Median nerve is supplied from what spinal nerves?
A
C5, C6, C7, C8 and T1
24
Q
What cords form the median nerve?
A
Medial and lateral cords
25
What does the median nerve supply?
* Supplies flexors of forearm, LOAF muscles
* Supplies sensation to radial 3.5 digits
26
What nerve supplies this area?
Median nerve
27
What forms the floor and the roof of the carpal tunnel?
* Floor
* Carpal bones
* Roof
* Flexor retinaculum
28
What are the contents of the carpal tunnel?
* FDS x 4
* FDP x 4
* FPL
* Median nerve
* Ie, above is 9 tendons and a nerve
29
What are some causes of carpal tunnel syndrome?
* Development
* Trauma
* Distal radius fracture
* Swellings
* Ganglion
* Fibroma
* Lipoma
* Inflammatory
* Rheumatoid
* Gout
* TB
* Amyloid
* Metabolic
* Pregnancy
* Mucopolysaccharidoses
* Hypothyroidism
30
Carpal tunnel syndrome involves what nerve?
Median nerve
31
What is the presentation of carpal tunnel syndrome?
* Nocturnal pain
* Parasthesia in part or all of median nerve distribution
* Wasting of the thenar muscles
* Lack of sensation
32
What investigations are done for carpal tunnel syndrome?
* Tinnels test
* Phalens test
33
Whats the treatment of carpal tunnel syndrome?
* Splints
* Treat metabolic cause
* Steroid injection
* Surgery
* Divide roof of carpal tunnel to relieve pressure
34
Ulnar nerve is formed from what cord?
Medial cord
35
Does the ulnar nerve supply any muscles in the arm?
* No branches in arm
36
Ulnar nerve enters the forearm between what?
* Enters forearm between two heads of FCU
37
Ulnar nerve supplies what?
* Supplies medial half of FDP, FCU and all intrinsic muscles in hand apart from LOAF
* Sensation to ulnar 1.5 digits
38
What nerve supplies this area?
Ulnar nerve
39
Ulnar nerve runs through what tunnel?
Cubital tunnel
40
Where is the cubital tunnel?
* Cubital tunnel is between medial epicondyle and olecranon with fascial bands from FCU as roof
41
Cubital tunnel syndrome involves what nerve?
Ulnar nerve
42
What is the presentation of cubital tunnel syndrome?
* Numbness on ulnar side
* Difficulty with fine tasks
43
What is the presentation of ulnar nerve palsy?
* Wasting of muscles
* 1st webspace
* Guttering
* Hypothenar wasting
* Ulnar claw hand
* Hyperextension at MCPJ and flexion at IPJ
* Distal lesion has worse clawing than proximal lesion (known as Ulnar paradox)
44
What investigation is done for ulnar nerve palsy?
* Froment’s test
* Tests adductor pollicis (ulnar nerve) and flexor pollicis longus (median nerve)
* If ulnar nerve not working, patient will cheat and use FPL instead of adductor pollicis
45
What does the Froment's test test?
* Tests adductor pollicis (ulnar nerve) and flexor pollicis longus (median nerve)
* If ulnar nerve not working, patient will cheat and use FPL instead of adductor pollicis
46
What are the roots of the lateral femoral cutaneous nerve?
L2, L3
47
Describe the course of the lateral femoral cutaneous nerve?
Lies on surface of iliacus muscle, usually exits pelvis under lateral end of inguinal ligament but can vary
48
What does the lateral femoral cutanoeus nerve supply?
Purely sensory to lateral aspect of thigh
49
Compression of the lateral femoral cutaneous nerve causes what?
Compression causes “meralgia paraesthetica”:
* Presentation
* Pain
* Paraesthesia’s
50
What supplies this area?
Lateral femoral cutaneous nerve
51
What is the treatment for lateral femoral cutanoeus nerve palsy?
* Steroid injection guided by US
* Operation to release tunnel
52
What are the roots of the sciatic nerve?
L4-S3
53
What is the largest nerve in the body?
Sciatic nerve
54
Describe the course of sciatic nerve?
* Exits through sciatic foramen below piriformis muscles
* Runs deep to gluteus maximus muscle
55
What does the sciatic nerve supply?
* Hamstring (posterior)
* Part of adductor magnus
* All lower leg and foot muscles via terminal branches (tibial and common fibular nerves)
56
What can damage to sciatic nerve occur due to?
* Posterior dislocation of hip
* Intra-muscular injections
* During surgery or trauma
57
What roots supply the common fibular nerve?
L4-S2
58
What is the common fibular nerve a branch of?
Smaller and lateral branch of sciatic nerve:
* Passes around lateral aspect of neck of fibula
* Divides into superficial and deep fibular nerves
59
Deficits to common fibular nerve causes what?
Deficit causes foot drop and slapping gait
60
What is the most commonly injured nerve in the leg?
Common fibular nerve
