Peripheral nervs

Question 1

Name of space between Schwann cells myelin wrappings on nerve cells

Answer 1

Ranvier nodes (Na+ channels, K+ in internodes)

Question 2

Connective tissue in peripheral nerves and function

Answer 2

• Epineurium (30-75 of nerve cross section area - more around joints, shock absorbing and gliding)
• Perineurium (prolongation of meninges around fascicles maintaining osmosis, fluid pressure)
• Endoneurium (binds fascicle together)

Question 3

Seddon and Sunderland classification

Answer 3

Seddon (Sunderland)

Neurapraxia (Grade I)

Axonotmesis (Grade II-IV)
- II Axon injury
- III Axon + endoneurium injury
- IV Axon + endo + Perineurium Injury

Neurotmesis (Grade V)

Mixed (Grade VI) added later to classifications

Question 4

At what grade of injury does Tinell sign appear

Answer 4

Axonotmesis - Seddon classification

(Grade II - Sunderland classification)

May not be true in reality?

Question 5

Difference between demyelination and axonal damage on electrophysiology

Answer 5

Demyelination - delay

Axonal damage - decreased amplitude/voltage (fewer nerve fibers)

Conduction block (focal demyelination) - Often both delay and lower amplitude

Question 6

Different type of nerve injuries

Answer 6

Lesions
- Sharp division
- crush
- elongation
- avulsion
Degeneration

Question 7

What is retrograde degeneration

Answer 7

Degeneration occurs in distal nerve stump after lesion but also in proximal - retrograde. Starts immidiately and lasts 3-5d. If neuron survives regeneration starts after 6d.

More proximal injury more degeneration

Question 8

Wallerian degeneration

Answer 8

Degeneration in distal stump. After 3-5d the distal stump looses all electrical properties.. Proteolys and myelin degeneration.

Question 9

Proximal Median nerve compression sites

Answer 9

Ligament of Struthers (accessory origin of PT)
Bicipital aponeurosis
Underneath PT
FDS arch

Question 10

Possible explanation of normal tenar muscle in severe median nerve compression

Answer 10

Riche-Cannieu anastomosis from ulnar nerve

Question 11

Spurling test

Answer 11

Neck extension lateral deviation to symptomatic side and compression

Question 12

True phalens test

Answer 12

Both hands together in maximal flexion 1 min

Reverse phalanx (Madonna test) full extension 1 min

Question 13

3 ways to treat neuromas surgically

Answer 13

Bury in bone
RPNI - Regeneative periohersl berve interface (wrap in muscle)
TMR - targeted muscle reinnervation (3x siture muscle to denervated biceps branch in amputation)

Question 14

6 clinical features of CRPS

Answer 14

Pain
Swelling
Stiffness
Colour change
Vhanges in skin texture
Increased hair growth

Question 15

Hyperalgesia and allodynia meaning

Answer 15

Hyperalgesia - increased sensobility

Allodynia - normal stimuli is painful

Question 16

4 Budapest criterias

Answer 16

1. Sensory
2. Vasomotor
3. Sudomoto
4. Motor/trophic

Question 17

Bouvier test

Answer 17

Test if a Lasso operation will be enough

Question 18

CRPS type 1

Answer 18

No nerve injury

Type 2- with nerve injury

Question 19

Budapest criteria

Answer 19

1. Disproportionate pain
2. Report 1 symtom in 3 out of 4:
   - Sensory
   - Vasomotor
   - Edema/swetting
   - Motor/trophi
3. Show 1 sign in 2 our of 4 (above)
4. No other diagnosis

Question 20

Vitamin C dosage for CRPS

Answer 20

500mg 50 days (200mg for impaired renal function)