Lower Limb Nerve Injury

Question 1

Sacral roots come out?

Answer 1

T12 to L1

Question 2

Lumbar puncture happens at?

Answer 2

L3/4

Question 3

Cauda equina symptoms?

Answer 3

Radicular pain, spreading out electrical
Unilateral pain
Sensory disturbance unilateral
Sexual Function is less impaired

Question 4

Disc herniation that compressing cauda equina happens at what level?

Answer 4

L5/S1

Question 5

Knee jerk at which level?

Answer 5

L4

Question 6

ANkle jerk at which level?

Answer 6

S1

Question 7

Femoral nerve comes off which level?

Answer 7

L2,3 and 4

Question 8

Sciatic nerve comes off

Answer 8

L4/5 S 1 2 3

Question 9

Femoral nerve organisation?

Answer 9

Psoas iliacus before inguinal ligament

Then below, innervation to knee extensors

Question 10

Lateral cutaneous nerve comes off?

Answer 10

L2/3, below inguinal ligament

Question 11

Numbness outer lateral thigh will be due to?

Answer 11

Lateral cutaneous nerve damage

Question 12

Common perineal winds around?

Answer 12

Fibular head

Question 13

Tibial nerve is responsible for?

Answer 13

Inversion and flexion of everything

Question 14

Which nerve would you use for nerve biopsy?

Answer 14

Sural nerve

Question 15

Plexopathy?

Answer 15

When proximal part of limb affected

Question 16

Differences between cauda equina and conus medullaris?

Answer 16

Conus:
Less severe pain,
Symmetrical 
Bilateral
Ankle reflex only reduced
Bowel/bladder symptoms are early
Sexual function impairement is more

Question 17

What is sciatica caused by?

Answer 17

usually L5, s1 n root impingement

Question 18

Dermatomes?

Answer 18

L1, inguinal area
L2, front of thigh
L3 front of knee
L4, front - inner medial leg
L5, outer leg, dorsum o foot inner sole
S1, little toe, rest of sole, back of leg
S2, thighs to top of buttock
S3-s5 concentric rings around anus, genitalia

Question 19

Femoral nerve damage can happen due to?

Answer 19

Gynaecological reasons and pelvic fracture

Question 20

Isolated hip fracture affects what and what does pelvic and sacral fractures affect?

Answer 20

Sciatic nerve

Sacral plexus

Question 21

What can cause sciatic nerve injury?

Answer 21

Hip dislocation,
Acetabular fracture
Surgical trauma
Injections
Radiation
Tourniquets
Positioning during anaesthesia

Question 22

If you injure the tibial nerve then you can’t?

Answer 22

Stand on tip toes
Weak foot inversion
Painful numb sole

Question 23

Tibial nerve gives branches off to?

Answer 23

Gastrocnemius, popliteus, soleus, plantaris and the sural nerve

Question 24

What are the causes of tibial nerve injury?

Answer 24

Trauma.
Bakers cyst
Nerve tumour
Entrapment by the tendinous arch of the soleus muscle

Question 25

Sural nerve supplies?

Answer 25

Lateral foot

Question 26

Common fibular nerve damaged by?

Answer 26

Tight plaster casts, leg crossing, prolonged squatting Strawberry’s pickers Slimmers palsy

Question 27

Common peroneal nerve damage?

Answer 27

Sensory loss in dorsum of foot and outer aspect of leg Weakness of dorsi flexion and eversion of foot

Question 28

Length dependent poly neuropathy causes?

Answer 28

``` Alcohol Vit b12 deficiency Diabetes Idiopathic Chemotherapy ```

Question 29

Clinical symptoms of length dependent polyneuropathy?

Answer 29

Numbness Paraesthesia Weakness Pain

Question 30

Non-length dependent polyneuropathy?

Answer 30

Guillian barre syndrome Post infection inflammatory condition that picks off peripheral nerves Antibody injures myelin membranes or axonal

Question 31

Symptoms of GB syndrome?

Answer 31

Rapidly progressive days to weeks Weakness including limbs facial respiratory and bulbar muscles Absent reflexes

Question 32

Neuronopathy?

Answer 32

Affecting the cell body of the nerve

Question 33

What is compartment syndrome?

Answer 33

Increases in pressure within a myofascial compartment which has limited ability to expand. This leads to compromised circulation and function of the tissues Acutely it is a surgical emergency

Question 34

Commonest site for compartment syndrome?

Answer 34

Leg and forearm

Question 35

What percent of tibial fractures are associated with compartment syndrome?

Answer 35

1-10%

Question 36

Signs of compartment syndrome?

Answer 36

``` Pain on passive movement Tense limb Reduced sensation Muscle weakness paralysis Pallor Reduced pulse ```

Question 37

Investigations for compartment syndrome?

Answer 37

CK Raised lactate Myoglobinuria