peripheral nerve injuries

Question 1

structure of peripheral nerve

Answer 1

axons coated in endoneurium
grouped into fascicles covered with perineurium
grouped to form a nerve covered in epineurium

Question 2

types of fibres

Answer 2

A alpha
A beta
A gamma
A delta
B
C largest and slowest

Question 3

neurapraxia

Answer 3

trauma to nerve in continuity
stretched or bruised
reversible conduction block due to local ischaemia or demyelination
prognosis good

Question 4

axonotmesis

Answer 4

endoneurium intact but disruption of axons
stretched or crushed or direct blow
wallerian degeneration (distal to site of injury)
prognosis fair
can regrow back to length of endoneurium

Question 5

neurotmesis

Answer 5

complete nerve division
no endoneurium
laceration or avulsion
no recovery unless repaired
prognosis poor
can be grade 3,4 or 5

Question 6

closed nerve injuries

Answer 6

neuropraxis or axonotmesis
spontaneous recovery is possible
surgery indicated after 3 months if no recovery identified
axonal growth rate (1-3mm/day)

Question 7

open nerve injuries

Answer 7

open wound
nerve division
neurotmetic
treated with early surgery

Question 8

regeneration proceeds at rate of about

Answer 8

1mm/day (1 inch per month)
pain is first to return

Question 9

what is worse- proximal lesion or distal lesion

Answer 9

proximal

Question 10

how can healing be tested and monitored

Answer 10

tinels sign
electrophysiological nerve conduction studies

Question 11

immediate surgery within 3 days for

Answer 11

clean and sharp injuries

Question 12

early surgery within 3 weeks for

Answer 12

blunt/ contusion injuries

Question 13

delayed surgery within 3 months for

Answer 13

closed injuries