Nerve palsies Flashcards
1
Q
Nerve palsies of the upper limb?
A
> Nerve Roots > Brachial Plexus > Peripheral Nerves - Axillary - Radial - Musculocuteneous - Ulnar - Median
2
Q
Nerve palsies of the lower limb?
A
> Nerve Roots
> Sacral and Lumbar Plexus
> Peripheral Nerves
- Sciatic
- Femoral
- Common Peroneal
- LFCN
3
Q
Which dermatome - Index finger?
A
C7
4
Q
Which dermatome - little finger?
A
C8
5
Q
Which dermatome - Lateral forearm?
A
C6
6
Q
Which dermatome - thumb?
A
C6
7
Q
Which dermatome - medial forearm?
A
Proximally = T1 Distal = C8
8
Q
Which dermatome - Medial upper arm?
A
T1
9
Q
Which dermatome - axilla?
A
T2
10
Q
Which dermatome - Outer upper arm?
A
C5
11
Q
Which dermatome - Medial aspect of the upper arm, supinated?
A
C6
12
Q
Which dermatome - Medial aspect of forearm, pronated?
A
C7
13
Q
Which dermatome - big toe?
A
L4
14
Q
Which dermatome - Middle foot?
A
L5
15
Q
Which dermatome - Lateral aspect of heel?
A
S1
16
Q
Which dermatome - Medial aspect heel?
A
L3
17
Q
Which dermatome - Lateral aspect of lower leg, posterior?
A
S1
18
Q
Which dermatome - medial aspect of lower leg, posterior?
A
L3
19
Q
Which dermatome - Lateral aspect of lower leg, anterior?
A
L5
20
Q
Which dermatome - Lateral aspect of lower leg, anterior?
A
L4
21
Q
Which dermatome - Lateral aspect of upper leg, posterior?
A
L5
22
Q
Which dermatome - middle aspect of upper leg, posterior?
A
S1
23
Q
Which dermatome - medial aspect of upper leg, posterior?
A
L3
24
Q
Which dermatome - Lateral aspect of upper leg, anterior?
A
L4
25
Which dermatome - medial aspect of upper leg, anterior?
L3
26
Which dermatome - groin area?
L2 distal
| L1 proximal
27
Myotone patterns - Elbow flexors?
C5
28
Myotone patterns - Wrist flexors?
C6
29
Myotone patterns - elbow extensors?
C7
30
Myotone patterns - Finger extensors?
C8
31
Myotone patterns - intrinsic muscles of the hand ?
T1
32
Myotone patterns - hip flexors ?
L2
33
Myotone patterns - Knee extensors?
L3
34
Myotone patterns - ankle dorsiflexion?
L4
35
Myotone patterns - Long toe extensors?
L5
36
Myotone patterns - ankle plantar flexors?
S1
37
Upper limb nerve palsies - Brachial plexus?
Brachial Plexus
> Erb’s Palsy
> Klumpke’s Palsy
> Total Brachial Plexus
38
Upper limb nerve palsies - Peripheral nerves?
Peripheral Nerves
> Musculocutaneous (nil)
> Axillary
- Axillary nerve palsy secondary to trauma
> Radial
- Radial nerve palsy secondary to compression or entrapment
> Median
- Carpal tunnel syndrome
> Ulnar
- Cubital Tunnel Syndrome
39
Upper limb nerve palsies - Axillary nerve?
Usually secondary to trauma
40
Upper limb nerve palsies - radial nerve?
Usually die to compression or entrapment
41
Upper limb nerve palsies - Median nerve?
Carpal tunnel syndrome
42
Upper limb nerve palsies - Ulnar?
Cubital tunnel syndrome
43
How many nerve roots in the brachial plexus?
5 = C5 - T1
44
Which nerves form the superior trunk of the upper limb?
Roots C5 and C6
45
Which nerves form the middle trunk of the upper limb?
Root C7
46
Which nerves form the inferior trunk of the upper limb?
C8 and T1 Roots
47
Which nerves roots form the musculocutaneous nerve of the upper limb?
C5, C6 and C7
48
Which nerves roots form the radial nerve of the upper limb?
C5, C6, C7, C8, T1
49
Which nerves roots form the median nerve of the upper limb?
C5, C6, C7, C8, T1
50
Which nerves roots form the ulnar nerve of the upper limb?
C7, C8 and T1
51
What runs posterior to the median nerve immediately distal to the axilla?
The axillary artery
52
What is an upper brachial plexus palsy??
C5 and C6 = Erb-Duchenne palsy
53
What is an lower brachial plexus palsy??
> C8 and T1
> Klumpke's palsy
> Very rare
54
What is an total brachial plexus palsy??
> C5 - T1
55
How does someone present with Erb-Duchenne palsy?
Waiter's tip position:
> Shoulder is adducted
> Elbow is extended and pronated
> Wrist is flexed
C5, C6 damage (Deltoid, shoulder muscles, brachialis and biceps)
56
What can cause Erb-Duchenne palsy?
> Brachial plexus is stretched leading to downward traction of C5 and C6 (+/- C7)
> Shoulder/arm pulled down as neck is pulled in opposite direction
57
What can cause Klumpke's palsy
> Upward Traction of C8/T1
> Shoulder/arm is pulled up, away from body e.g. hanging from a branch or arm pulled during childbirth
58
How would one present with Klumpke's palsy?
Affect small muscles of the hand = Claw hand
59
What is the route of the muculocutaneous nerve (C5, 6, 7)?
1) Lateral cord
2) Pierce coracobrachialis
3) Runs inferiorly between biceps ad brachialis
4) Terminates as the lateral cutaneous nerve to the forearm
60
What does the musclulocuatneous (C5, 6, 7) nerve supply?
> Biceps brachii
> Brachialis
> Elbow joint
> Lateral cutaneous nerve
61
What is Hilton's Law? Give an example?
“ A sensory nerve supplying a JOINT also supplies the MUSCLES
moving the joint and the SKIN overlying the insertions of these muscles.”
Eg. Musculocutaneous Nerve gives sensory supply to anterior capsule of elbow, and supplies the BBC and skin overlying the insertions of these muscles, by way of the lateral cutaneous nerve of the forearm (which is the terminal branch of the MCC nerve)
62
What is the route of the axillary nerve (C5, 6)?
1) Posterior cord
| 2) Wraps around the surgical neck of the humerus
63
What does the axillary nerve (C5, 6) supply?
> Deltoid
> Teres major
> Skin over the lateral arm
64
What can cause an axillary nerve (C5, 6) palsy?
> Dislocation of the shoulder
| > Fracture of the surgical neck of the humerus
65
If there is a nerve palsy and deltoid atrophy, what is likely to be the cause?
Axillary nerve (C5, 6) palsy
66
What is the route of the radial nerve (C5, 6, 7, 8, T1)?
1) Posterior cord
2) Runs in radial groove of humerus as it passes from medial to lateral
3) PIN (motor) and SRN (sensory) branches
67
What does the radial nerve (C5, 6, 7, 8, T1) supply?
```
> Triceps brachii
> Brachioradialis
> Extensor carpi radialis brevis
> Extensor carpii brevis
> Extonsors
> Superficial radial nerve
```
68
What can cause radial nerve palsy (C5, 6, 7, 8, T1)?
Entrapment:
- Fracture of the distal humerus
Compression:
- Saturday night palsy
- Honeymoon palsy
- Crutch palsy
69
How would someone present with radial nerve palsy?
Symptoms depend on SITE of lesion
> In axilla: loss of elbow extension, wrist extension and sensory changes 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) eg. handcuffs
70
What does the median nerve (C5, 6, 7, 8, T1) supply?
> Flexors of the forearm (Bar FCU and medial half of FDP), LOAF muscles
> Supplies sensation to radial 3.5 digits
71
Median nerve - sensory?
Supinated:
- Thumb
- 1st, 2nd and 1/2 3rd digits
- 1/2 Palm of hand
Pronated:
- Tip of thumb
- Tips of 1st, 2nd and 1/2 3rd digits
72
Radial nerve - sensory?
Supinated:
- Proximal aspect of lateral thumb
Pronated:
- 1/2 hand thumb side
- 1st, 2nd and 1/2 3rd digits not including tips
73
Ulnar nerve - sensory?
- Outer aspect of hand
| - 1/2 3rd and 4th digits
74
What makes up the floor of the carpal tunnel?
Carpal bones
75
What makes up the roof of the carpal tunnel?
Flexor retinaculum
76
What are the contents of the carpal tunnel?
> Flexor Digitum Superficialis x4 tendons
> Flexor Digitorum Profundus x4 tendons
> Flexor Pollicus Longus tendons
> Median nerve
77
Carpal tunnel syndrome - Causes?
Developmental
Trauma:
- Distal radius fracture
Swellings:
- Ganglion
- Fibroma
- Lipoma
Inflammatory:
- Rheumatoid
- Gout
- TB
- Amyloid
Metabolic:
- Pregnancy
- Mucopolysaccharidoses
- Hypothyroidism
78
Carpal tunnel syndrome - Causes, trauma?
Trauma:
| - Distal radius fracture
79
Carpal tunnel syndrome - Causes, metabolic?
Metabolic:
- Pregnancy
- Mucopolysaccharidoses
- Hypothyroidism
80
Carpal tunnel syndrome - Causes, inflammatory?
Inflammatory:
- Rheumatoid
- Gout
- TB
- Amyloid
81
Carpal tunnel syndrome - Causes, swellings?
Swellings:
- Ganglion
- Fibroma
- Lipoma
82
Carpal tunnel syndrome - Clinical presentation?
Nocturnal pain and parasthesia in part or all of the median nerve distribution
Wasting of the thenar muscles
83
Carpal tunnel syndrome - diagnosis?
LOOK
> Thenar wasting
> Previous scars
> Deformity (previous fracture)
FEEL
> Sensation
MOVE
> APB power
SPECIAL TESTS
> Tinnels
> Phalens
84
Carpal tunnel syndrome - Treatment?
Carpal tunnel release
85
How many branches does the ulnar nerve (C8, T1) have in the arm?
None
86
How does the ulnar nerve (C8, T1) enter the forearm?
Between the two heads of the flexor carpi ulnaris
87
What does the ulnar nerve (C8, T1) supply?
> Medial half of the flexor digitorum profundus
> Flexor carpi ulnaris
> Intrinsic muscles in hand BAR LOAF
> Sensation to 1/2 3rd and 4th digits
88
Cubital tunnel syndrome - clinical presentation?
Patient has numbness on ulnar side of hand and difficulty with fine tasks.
89
What is the cubital tunnel?
Cubital tunnel between Medial epicondyle and olecranon, with fascial bands from Flexor carpi ulnaris as roof
90
Ulnar nerve palsy - Clinical presentation?
> Wasting of muscles of hand:
- 1st webspace often most marked
- Guttering
- Hypothenar wasting
> Ulnar claw hand:
- Hyperextension at MCPJ, flexion at IPJ's
91
What is the ulnar paradox?
A distal lesion has worse clawing than a proximal lesion, due to intact long flexors with a distal lesion
92
Which test is useful in diagnosis of ulnar nerve palsy?
Fronment's test:
> Key muscles:
- ADDUCTOR Pollicis (ULNAR NERVE)
- FLEXOR Pollicis Longus (MEDIAN NERVE)
> If Ulnar nerve not working, the patient will cheat and use FPL instead of Adductor Pollicis
93
Fronment's test?
> Useful in diagnosis of ulnar nerve palsy
> Key muscles:
- ADDUCTOR Pollicis (ULNAR NERVE)
- FLEXOR Pollicis Longus (MEDIAN NERVE)
> If Ulnar nerve not working, the patient will cheat and use FPL instead of Adductor Pollicis
94
Lower limb palsies?
Sacral Plexus
> Sciatic:
- Common Peroneal Nerve
- Tibial Nerve
Lumbar Plexus:
> Femoral Nerve
95
Which nerve roots form the sacral plexus?
L4 to S4
96
What does the superior gluteal nerve supply?
> Gluteus medius
> Gluteus minimus
> TFL
97
What does the inferior gluteal nerve supply?
Gluteal maximus
98
What is the main branch of the sacral plexus?
Sciatic nerve, supplies:
- Posterior thigh
- Leg
- Foot muscles
99
What are the branches of the sacral plexus?
```
> Superior gluteal
> Inferior gluteal
> Sciatic
> Posterior femoral
> Pudendal
```
100
Branches of the sciatic nerve?
> Tibial nerve
| > Common fibular nerve
101
What does the sciatic nerve supply?
Hamstring muscles in posterior compartment of thigh
102
Route of the common fibular nerve?
1) Wraps around the neck of the fibula
| 2) Divides into deep fibular nerve and superficial fibular nerve
103
What does the deep fibular nerve supply?
Anterior compartment of the leg
104
What does the superficial fibular nerve supply?
Lateral compartment of the leg
105
What is the mechanism of action of the muscles in which the common fibular nerve supply?
Muscles of the anterior leg which raise the foot, dorsiflexion
106
If there is damage to the common fibular nerve what is the clinical outcome?
> There is loss of dorsiflexion = Foot drop
| > Cannot raise foot
107
In terms of the femoral plexus which nerve supplies the anterior compartment of the lower leg?
Deep fibular nerve
108
In terms of the femoral plexus which nerve supplies the lateral compartment of the lower leg?
Superficial femoral nerve
109
In terms of the femoral plexus which nerve supplies the posterior compartment of the lower leg?
Tibial nerve
110
What are the branches of the lumbar plexus?
```
> Iliohypogastric (T12, L1)
> Ilioinguinal (T12, L1)
> Genitofemoral (L1, L2)
> Lateral cutaneous (L2, L3)
> Femoral (L2, L3, L4)
> Obturator (L2, L3, L4)
```
111
What are the main branches f the lumbar plexus?
> LFCN (L2, L3)
> Femoral (L2, L3, L4)
> Obturator (L2, L3, L4)
112
Which nerve roots make up the lumbar plexus?
L1-L5
113
Meralgia parasthetica - Clinical presentation?
Altered sensation and pain lateral thigh
114
Meralgia parasthetica - Cause?
Compression of Lateral femoral cutaneous nerve of thigh as it travels under lateral border of inguinal ligament
115
What is a dermatome?
> Sensory area of skin supplied by a single spinal nerve
> Adjacent dermatome overlap considerably
116
Good pneumonic for sacral dermatomes, the 4 S's.
STAND on S1
SLEEP on S2
SIT on S3
SHIT on S4 !
117
Why could hip disease give rise to knee pain?
```
Due to Hilton's law:
“The motor nerve to a
muscle tends to give
a branch of supply to
the joint that the
muscle moves, and
another to the skin
over the joint.”
```
118
Which nerves supply the hip joint?
Hip joint is supplied by:
> Obturator nerve (predominately)
> Femoral nerve
> Lateral femoral cutaneous nerve
119
What is a myotome?
A group of muscles supplied by one segment of spinal cord
120
How does axillary nerve palsy clinically present?
Motor deficit = Loss of shoulder abduction (Deltoid)
Sensory deficit = Badge area
121
How does radial nerve palsy clinically present?
> Motor deficit - wrist drop (extensors)
> Sensory deficit - 1st web space dorsally
122
How does median nerve palsy clinically present?
> Complication of - carpal tunnel syndrome, wrist lacerations (& supracondylar #’s, Struther’s ligament)
> Motor deficit - thenar wasting (monkey hand), pointing finger
> Sensory deficit - volar aspect thumb
123
How does ulnar nerve palsy clinically present?
> Complication of - humeral condyles (& wrist lacerations)
> Motor deficit - claw hand, hypothenar & 1st dorsal interosseous wasting
> Sensory deficit - little finger
124
Where is the lumbar plexus located?
Lies on surface of quadratus lumborum and within body of psoas muscle
125
Nerve supply of the femoral nerve?
L2-L4
126
Which of the branches of the lumbar plexus are the larger?
Femoral nerve
127
What is the route of the femoral nerve?
1) Passes through psoas muscle
2) Exits pelvis under inguinal ligament, lateral to femoral artery, vein and lymphatic channels in femoral triangle - VAN with Vein next to “V” of legs
3) Terminates in long fine sensory branch (Saphenous Nerve - accompanies femoral artery in subsartorial canal of thigh, and long saphenous vein in lower leg and in front of medial malleolus at ankle to supply great toe)
128
Saphenous nerve?
Saphenous Nerve - accompanies femoral artery in subsartorial canal of thigh, and long saphenous vein in lower leg and in front of medial malleolus at ankle to supply great toe
129
What is the route of the Lateral femoral cutaneous nerve?
Lies on surface of iliacus muscle; usually exits pelvis under lateral end of inguinal ligament, but variable
130
What does the lateral femoral cutaneous nerve supply?
Purely sensory to lateral aspect thigh
131
What is the largest nerve in the body? What is it a branch of?
> The Sciatic nerve
> The main branch of sacral plexus
> Broad and flat with accompanying artery
132
How does the sciatic nerve exit the pelvis?
Through the sciatic foramen below piriformis muscle
133
Which muscle does the sciatic nerve run deep to?
The gluteus maximus muscle
134
When is the sciatic nerve at risk of damage?
> Posterior dislocation of hip
> Intra-muscular injections
> During surgery (division devastating)
135
The sciatic nerve supplies what?
Supplies hamstring muscles in thigh (posterior) and part of adductor magnus, and all lower leg and foot muscles via terminal branches (tibial and common fibular nerves) - height of division variable (really 2 nerves)
136
What are other names for the common fibular nerve?
It was previously called lateral popliteal nerve, then common peroneal nerve
137
There are communicating branches of the common fibular nerve to which nerve?
The sural nerve
