IAN Injury

Question 1

Which term describes a painful response characterized by delayed onset after initial application of the stimulus which often builds in intensity with repeated application of the stimulus (crescendo), and persists for a variable period after discontinuation (afterglow)?

Answer 1

Hyperpathia

Question 2

What is the purpose of diagnostic blocks and what do they imply?

Answer 2

If the block causes resolution of the pain symptoms, then the injury is distal to the blocks and the pt may be a candidate for microsurgery. If not then the issue may be central

Question 3

After how much time would you determine return of sensation is dismal?

Answer 3

3 months

Question 4

Painful symptoms should be treated how long after injury?

Answer 4

Within 6 months after injury

Question 5

What could happen if symptoms of allodynia or hyperpathia are allowed to persist longer than 12 months after injury?

Answer 5

Intractable pain syndrome which can be resistant to medical and surgical intervention and can be debilitating

Question 6

Name 3 medications which can be used for neuropathic pain

Answer 6

Clonazepam (Klonopin) 0.5mg Q8H
Gabapentin (Neurontin)
Pregabalin (Lyrica)

Question 7

What is the term which describes a painful response to non- noxious stimuli

Answer 7

Allodynia

Question 8

Within what time frame after injury is nerve repair most successful?

Answer 8

Within 6 months

Large drop off after 9-12 months

Question 9

At what age do success rates for IAN repair significantly decrease?

Answer 9

51

Question 10

Name 2 autogenous sources for IAN nerve graft

Answer 10

Sural nerve

Great auricular nerve

Question 11

Where is the deficit in a pt who gets a sural nerve graft harvested?
Who might you not want to do that?

Answer 11

Lateral foot and heel

Athletes, climbers, runners who rely on position sense of the foot

Question 12

How do you minimize risk of pain symptoms at the sural nerve or great auricular nerve harvest site?

Answer 12

Nerve redirection procedure: suture the proximal stump to the SCM or gastrocnemius
Or
Epineural capping

Question 13

What is the maximum length that can be harvested from a great auricular nerve?

Answer 13

3cm

Question 14

What is the maximum gap in which transection of the incisive nerve may give you adequate length to reapproximate the IAN?

Answer 14

1cm

Question 15

What are used to perform a contact detection test?

Answer 15

Von Frey fibers

Plastic or acrylic rods with nylon fibers of varying thickness which require varying amounts of pressure to bend