Peripheral nerve injury

Question 1

What kind of nerve injury is typical of a palsy?

Answer 1

Compression

Question 2

How can nerves be compressed?

Answer 2

Space within nerve is reduced for the median nerve at the wrist (carpal tunnel)
Spinal root may be compressed by intervertebral disc (sciatica)
Morton’s neuroma

Question 3

What is neuropraxia?

Answer 3

Nerve is in continuity but is injured

Reversible conduction block due to ischaemia or demyelination

Question 4

What is axontmesis?

Answer 4

Endoneurium is in continuity but axon is disrupted

Wallerian degeneration

Question 5

What is neurotmesis?

Answer 5

Complete nerve division
Laceration or evulsion
No recovery unless repaired

Question 6

What is a closed nerve injury?

Answer 6

Associated with injuries in continuity

Neuropraxis, axontmesis

Question 7

What is an open nerve injury?

Answer 7

Associated with neurotmetic injury

Knife, glass etc.

Question 8

Is nerve healing fast or slow?

Answer 8

Slow

Proximal axonal budding occurs after about 4 days

Question 9

What may nerve healing depend on?

Answer 9

How distal/proximal the lesion is
Whether is sensory+motor or just one of the two
Mixed have worse prognosis

Question 10

What is Tinnel’s sign?

Answer 10

Monitors recovery

Tap over site of of nerve and paraesthesia will be felt as distally as regeneration has progressed