This document provides tips and instructions for using a PowerPoint presentation on peripheral nerve injuries. Some key points: - Slides can be freely downloaded, edited, and modified. Blank slides are included to facilitate active learning sessions where students provide input before viewing information on subsequent slides. - The presentation covers anatomy, mechanisms and causes of peripheral nerve injuries, classifications of nerve injuries (Seddon and Sunderland), diagnosis, treatment including conservative treatment and surgical indications, nerve regeneration and recovery, and chronic nerve entrapment. - References for further information are provided in notes slides at the end. Mobile access instructions and links to additional resources are also included.

1. Tips on using my ppt.
1. You can freely download, edit, modify and put your
name etc.
2. Don’t be concerned about number of slides. Half the
slides are blanks except for the title.
3. First show the blank slides (eg. Aetiology ) > Ask
students what they already know about ethology of
today's topic. > Then show next slide which enumerates
aetiologies.
4. At the end rerun the show – show blank> ask questions >
show next slide.
5. This will be an ACTIVE LEARNING SESSION x
three revisions.
6. Good for self study also.
7. See notes for bibliography.

2. PERIPHERAL NERVE INJURIES

3. A
N
A
T
O
M
Y
EPINEURIUM
PERINEURIUM
ENDONEURIUM
VESSELS

4. NERVE
INJURIES
Acute
injury
Chronic
injury
PERRIPHERAL NERVE INJUIES

5. Mechanisms of Injuries
• Crush / compression
• Stretch / traction
• Laceration / transection
• Metabolic disturbance
• Ischaemia
• Radiation
• Electrical injury
• Thermal injury

6. Causes

7. Causes
• Birth trauma –Erb’s Paralysis.
• Blunt Trauma/Traction/pressure/entrapment
• Sharp injury
• Fracture
• Surgery, Anesthesia
• Malignancy
• Burn

8. Some Iatrogenic nerve injuries

9. Some Iatrogenic nerve injuries
• IM. Injection
• Recurrent Laryngeal N. In thyroid surgery
• Facial N. In Parotid surgery
• N. to Serratus anterior- Axillary diessection
• Inguinodynia in Hernia.
• Pudendal n. In pelvic /prostate surgery.
• Brachial plexus during anesthesia

10. Primary injury
– Results from same trauma that injures a bone or joint
– Radial nerve is the most commonly injured. Of humeral
shaft fractures, 14 % is complicated by radial nerve injuries
– Displaced osseous fragments
– Stretching
– Manipulation
Secondary injury
– Results from involvement of nerve by infection, scar,
callous or vascular complications which may be hematoma,
AV fistula, Ischemia or aneurysm

11. Classification of nerve injuries

12. Classification of nerve injuries
Seddon Classification
1. Neuropraxia:
1. Minor contusion or compression with preservation of axis – cylinder of
myelin sheath.
2. Impulse transmission physiologically interrupted.
3. Complete recovery in a few days to weeks
2. Axonotmesis :
1. More significant injury
2. Breakdown of axon and distal Wallerian degeneration but with
preservation of schwann cell & endoneurial tubes
3. Spontaneous regeneration with good functional recovery can be expected
3. Neurotmesis
1. More severe injury
2. Complete anatomical severance, avulsion or crushing of nerve
3. Axon, Schwann cell & endoneurial tubes are completely disrupted
4. Spontaneous recovery cannot be expected unless surgically intervened

13. N e u r o p r a x i a
Mildest form, reversible conduction block
(function loss), for hours or days due to direct mechanical
compression, ischemia, mild burn
trauma or stretch

14. A x o n t m e s i s
Axonal and myelin sheath disruption while fascicular
integrity is maintained--Wallerian degeneration occurs
(prognosis is good—days, weeks)

15. N e u r o t m e s i s
Laceration from sharp or blunt forces causing complete disruption
of the axon and supporting connective tissue---very poor
prognosis without surgical repair

16. Sunderland Classification

17. Sunderland Classification
 Each degree of injury suggesting a greater anatomical
disruption with its correspondingly altered prognosis
 Anatomically various degrees (1st – 5th) represent injury
to
 Myelin
 Axon
 Endoneurial tube & it’s content
 Perineurium
 Entire nerve trunk
 Sixth degree (Mackinson) or mixed injuries occur in
which a nerve trunk is partially severed and
remaining part of trunk sustains 1st to 4th degree
injury.
 Mixed recovery pattern depending on degree of
injury to each portion of nerve.

19. Diagnosis of Peripheral nerve
injuries

20. Diagnosis of Peripheral nerve
injuries
• History
– Which nerve ?
– What level ?
– What is the cause ?
– What degree of injury ?
– Old or fresh injury ?

21. Diagnosis of Peripheral nerve
injuries
1. Motor:
– All muscles distal to the injury – paralyzed &
atonic
– Atrophy : 50 -70 % in 1st two months
– Striations & motor end plate configurations
retained for 12 – 18 months (critical limit of
delay)

22. 2. Sensory :
• Sensory loss usually follows a definite
anatomical pattern, although factor of overlap
from adjacent nerves may be present
• Weber 2 point discrimination test
• Tinel’s sign

23. Tinel's sign

24. Tinel's sign
• Tinel's sign is a way to detect
irritated nerves. It is performed by lightly
tapping (percussing) over the nerve to elicit
a sensation of tingling or "pins and needles"
in the distribution of the nerve. It takes its
name from French neurologist Jules Tinel
(1879-1952).

25. (3) Reflex
• Abolishes all reflexes transmitted by that
nerve, either afferent or efferent arc.
• Complete & incomplete lesion. So , not a
reliable guide to injury severity.
(4) Autonomic :
• Loss of sweating
• Loss of pilomotor response and
• Vasomotor paralysis in autonomous zone

26. (5) Others:
• Trophic Changes
• Esp. hand and feet
• Skin – thin, glistening, breaks easily to form ulcers
that heal slowly
• Fingernails
• Ridged, distorted and brittle
• Osteoporosis (Reflex sympathetic dystrophy)

27. Neuronal degeneration and regeneration

28. Neuronal degeneration and regeneration
• Any part of neuron detached from its nucleus,
degenerates & is destroyed by phagocytosis.
• Distal – Secondary / Wallerian Degeneration
• Proximal - Primary / Traumatic / Retrograde
Degeneration
• Time required for degeneration varies between sensory
and motor fibers and is also related to size & myelination
of fibers
• Advancing Tinel sign and presence of motor march
phenomena are signs of regeneration

29. Muscle atrophy
start : post-injury 1 month
peak : 3rd - 4th month

30. Electrodiagnostic studies

31. Electrodiagnostic studies
• Electromyography
• Nerve conduction velocity
• Strength duration curve

32. T r e a t m e n t
Time of
operation
Open
injury
Early
intervention
Delayed
intervention
Closed
injury
Delayed
intervention

33. C o n s e r v a t i v e t r e a t m e n t
Indications
Short history, mild-moderate, intermittent,
reversible cause (pregnancy, oral contraceptive,
endocrine abnormalities, type writer)
Method
Non-steroidal anti-inflammatory drugs, splint

34. S u r g i c a l I n d i c a t i o n s
Failed conservative treatment
Severe injury (sensory loss, muscle atrophy, motor weakness)

35. Indications for surgery

36. Indications for surgery
1. When a sharp injury has obviously divided a nerve.
2. When abrading, avulsing or blast wounds have rendered
the condition of nerve unknown
3. When a nerve deficit follows a blunt or closed trauma
& no clinical or electrical evidence of regeneration has
occurred after an appropriate time
4. When a nerve deficit follows a penetrating wound as
stab or low velocity gunshot wound, part observed for
evidence of nerve regeneration for appropriate time.

37. Types of Nerve Repair :

38. Types of Nerve Repair :
1. Endoneurolysis
2. Partial Neurorrhaphy
3. Neurorrhaphy
1. Epineural
2. Epi-perineural
3. Perineural
4. Nerve grafting
5. Motor Neerve Transfer

40. Time of Surgery

41. Time of Surgery
• Primary repair : First 6 – 8 hours
• Delayed primary repair : First 7 – 18 days
• Secondary repair : > 3 weeks

42. Factors that influence regeneration after neurorrhaphy

43. Factors that influence regeneration after neurorrhaphy
1. Age of patient
2. Gap between nerve ends
3. Delay between time of injury and repair
4. Level of injury
5. Condition of nerve ends
6. Experience & technique of surgeon

44. C h r o n i c N e r v e E n t r a p m e n t
Paresthesia
Loss
of function
Pain

45. P a t h o p h y s i o l o g y
Direct compression
Segmental demyelination
Wallerian degeneration(distal)
Ischemia
Swelling of nerve
Microcompartment SD

47. C a r p a l T u n n e l S y n d r o m e

48. PREGNANCY
TYPE WRITING

49. COMMON PERONEAL
Fracture of the head of fibula

50. Nerve Injury & Recovery
Motor
Proprioception
Touch
Temperature
Pain
Sympathetic
Recovery
Injury
Lee & Wolfe. Peripheral nerve injury & repair. JAAOS 2000

51. In clinical practice, how do you distinguish?
Axonotmesis versus Neurotmesis
• Nature of injury
• Serial observations
• Exploration
Seddon BMJ 1942
• (Imaging)

52. Prerequisites for Nerve Repair
• Skeletal stability
• Healthy tissue bed
• Healthy nerve ends
• No undue tension
• Adequate soft tissue coverage

53. Principles of Motor Nerve Transfers
• Donor nerve near target motor end plates
• Expendable donor nerve
• Pure motor donor nerve
• Donor-recipient size match
• Donor function synergy with recipient
function
• Motor re-education improves function
Mackinnon SE, Novak CB. Hand
Clin 1999

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4. Scan qr code from
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56. Get this ppt in mobile

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