Nerve injuries in the lower limb

Question 1

endoneurium

Answer 1

a connective tissue layer that surrounds each axon
consists of
-inner sleeve of material- glycocalyx
-mesh of collagen

Question 2

what are the blood vessels within the epineurium called that supply the nerves

Answer 2

vasa nervorum

Question 3

neuropraxia

Answer 3

• mildest type of nerve injury
• temporary physiological block and conduction in the affected axons without loss of axonal continuity. Endoneurium, epineurium and perineurium are all intact
• no wallerian degeneration

Question 4

axonotmesis

Answer 4

loss of continuity of the axons and their myelin sheath, but the endoneurium, perineurium and epineurium are preserved

wallerian degenertaion commences within 24-36 hours distal to the site of injury

axonal regernation occurs 1-3 mm/day

Question 5

neurotmesis

Answer 5

a partial or complete division of the axons, endoneurium, perineurium epineurium of a nerve fibre.

wallerian degeneration occurs distal to the site of injury and defects in neurons are defects

surgical intervention is necessary

Question 6

nerve repair process

Answer 6

inflammatory cells move to injured area and broken down by macrophage

nerve endings degenerate- schwannas cells proliferate from forget organ trying to reach cell body

nerves join up sucessfully to the injured part

if proliferation fails there’s disorganized axonal sprouting leading to a neuroma

Question 7

what myotome does hip flexion

Answer 7

L2

Question 8

what myotome does knee extension

Answer 8

L3

Question 9

what myotome does ankle dorsiflexion

Answer 9

L4

Question 10

what myotome does great toe extension

Answer 10

L5

Question 11

what myotome does ankle plantarflexion

Answer 11

S1

Question 12

what myotome does great toes flexion

Answer 12

S2

Question 13

where are the most common sites for slipped disc

Answer 13

L4/5

L5/S1

Question 14

where do lumbar nerve roots emerge

Answer 14

below their respective vertebrae

Question 15

why do the nerve roots tend to be compressed in ….

Answer 15

paracentral herniation

because they travel obliquely from the spinal cord to the intervertebral foramina

Question 16

what complications occur in L4 nerve root compression

Answer 16

weakness of ankle dorsiflexion and parasthesia in the L4 dermatome- medial leg and medial ankle

Question 17

what complications occur in L5 nerve root compression

Answer 17

weakness of dorsiflexion of great toe and parasthesia in L5 dermatome- lateral leg and dorsum of foot

Question 18

s1 nerve root compression complications

Answer 18

weakness of ankle plantarflexion (which manisfests as inability to stand on tip-toe) and parasthesia in the s1 dermatome- lateral border of foot, sole of foot, heel.

ankle reflex is diminished or absent

Question 19

what is the largest nerve in the body

Answer 19

sciatic nerve

nerve roots L4 - S3

Question 20

what is piriformis syndrome

Answer 20

sciatica-like symptoms that do not originate from compression of the spinal nerve roots, but instead are due to compression of the sciatic nerve by the piriformis muscle

Question 21

symptoms of piriformis syndrome

Answer 21

a dull ache in the buttock
typical sciatica pain in the thigh, leg and foot
pain when walking up stairs or inclines 
increased pain after sitting 
reduced range of motion of the hip joint

Question 22

treatment of piriformis syndrome

Answer 22

activity modification
non-steroidal anti-flammatory drugs (NSAIDS)
physiotherapy

Question 23

meralgia parasthetica

Answer 23

compression of the lateral cutaneuous nerve of the thigh as it pierces the inguinal ligament or as it pierces the fascia lata in the thigh

Question 24

what does the sciatic nerve innervate

Answer 24

L4 - S3
hamstring muscles
hamstring portion of the adductor magnus
-the common peroneal component innervates the short head o biceps femoris and all other hamstrings are innervated by the tibial component

Question 25

what does the superficial and deep peroneal nerve innervate

Answer 25

proximal part of lateral leg and dorsum of the foot

Question 26

what does the superior gluteal nerve supply

Answer 26

L5 and S1

the gluteus medius and minimus muscles and the tensor fasica latae

Question 27

what is a sign of superior gluteal nerve injury

Answer 27

the pelvis on the contralateral side will drop and foot will catch with the ground

Question 28

what does the femoral nerve innervate

Answer 28

L 2 3 4
the anterior thigh muscles that flex the hip joint- pectinues, iliacus and sartorius)

muscles that extend the knee- quadriceps femoris: rectus femoris, vastus lateralis, vastus medialis and vastus intermedius

Question 29

where is the sensory distribution of the femoral nerve

Answer 29

anteromedial thigh- via anterior femoral cutaneous nerve or medial and intermediate cutaneous nerve of thigh

medial side of leg and foot- via saphenous nerve

Question 30

what does the tibial nerve innervate

Answer 30

deep and superficial posterior compartments of the leg

-gastroceminus and soleus

Question 31

what does the superficial peroneal nerve innervate

Answer 31

lateral compartment of the leg

L4 - S1

Question 32

what does the deep peroneal nerve innervate

Answer 32

L4 , 5
innervates the anterior compartment of the leg- extensor digitorum longus, tibialis anterior, extensor hallucis longus, extensor digitorium longus, peroneus tertius

Question 33

what does the sural nerve supply

Answer 33

skin of the lateral ankle and the lateral border of the foot