Nerve Injuries

Question 1

Grade 1 nerve injury

Answer 1

Neurapraxia

Question 2

Grade 2 nerve injury

Answer 2

Axonotmesis

Question 3

Grade 3 nerve injury

Answer 3

Neurotmesis

Question 4

What can cause neurapraxia?

Answer 4

• crush injury

- prolonged pressure

Question 5

Saturday night palsy

Answer 5

• fall asleep heavily after drinking/drugs

- in a position where nerves are stretched (i.e. hanging on the brachial plexus)

Question 6

How can neurapraxia be induced medically?

Answer 6

• left in a position that compromises a nerve

- can get after having a vent (arm up against a bedrail for a long period of time)

Question 7

neurapraxia and sailing communities

Answer 7

• prop up legs on guidelines for a long time

- peroneal nerve neurapraxia

Question 8

How long does it generally take for neurapraxia to heal?

Answer 8

1-3 months

Question 9

What will you see on NCV from neurapraxia?

Answer 9

• decreased speeds

- still there, will have some return

Question 10

What is axonotmesis?

Answer 10

• get axonal disruption

- myelin sheath is intact

Question 11

How fast do nerves grow?

Answer 11

1-2 mm per day

Question 12

If the myelin sheath is still intact, how does this impact healing?

Answer 12

• will recover more easily

- nerve will know where to grow

Question 13

How long does it typically take for an axonotmesis injury to recover?

Answer 13

• 3-6 months

- depends on how far up the nerve the injury is

Question 14

Where on the nerve will an axonotmesis take less time to heal?

Answer 14

distal end of neuron

Question 15

What can cause a neurotmesis?

Answer 15

• cut or avulsion

- bad injury

Question 16

In neurotmesis, what is disrupted?

Answer 16

• myelin sheath

- axon

Question 17

Disruption of myelin sheath and axon: impacts on recovery

Answer 17

• nerve doesn’t know where to grow

- no input to tell it where to grow correctly

Question 18

How long does it take for a neurotmesis to heal?

Answer 18

• 1-2 years

- may not ever heal