1. PERIPHERAL NERVE INJURIES
By: M. Rustom
General, Plastic & Reconstructive Surgeon
MRCS (London)
Ms Surg/Plastic, Malaya
Fellowship in Plastic & Reconstructive Surgery, Malaya

2. Contents Overview Anatomy Pathophysiology Classification
Mechanism of Injury
Clinical Presentation
Management
Prognosis

3. Peripheral nerve injuries may result in loss of motor function, sensory function, or both.
Paul of Aegina ( ) was the first to describe approximation of the nerve ends with wound closure.
Hueter (1871, 1873) introduced the concept of primary epineurial nerve suture.
Loebke described bone shortening to decrease nerve tension in 1884.
In 1876, Albert described grafting nerve gaps.
Egloff and Narakas, 1983 were the 1st to discuss the use of Fibrin glue as an alternative to the classic suture repair method.
Overview

4. Anatomy

5. PATHOPHYSIOLOGY
May result in demyelination, axonal degeneration, or both.
Disruption of sensory, motor function or both depending on the location & the severity of the injury.
Recovery is influenced by the capacity of remyelination, axonal regeneration & reinnervation of the nerve ending units.
Wallerian degeneration.
Schwann cell proliferation.
Axonal sprouting.

6. MECHANISM OF INJURY Stretching injury:
- 8% elongation will diminish nerve's microcirculation
- 15% elongation will disrupt axons
Compression or crush injury:
- local ischemia.
- Local toxic metabolites.
- External pressure:
30mm Hg can cause paresthesias .
60 mm Hg can cause complete block of conduction

7. MECHANIS OF INJURY Laceration nerve damage:
- continuity of nerve disrupted, leading to :
. Ends retract
. Nerve stops producing neurotransmitters
. Nerve starts producing proteins for axonal regeneration

8. CAUSES Trauma. Prolong ischemia Excessive traction
Surgical / Iatrogenic
Metabolic
Acute compression
Thermal injury
Electrical injury
CAUSES

9. TYPES

10. CLASSIFICATION

11. CLASSIFICATION

12. CLASSIFICATION

13. Depends on the location & the nerve involved.
Sensory deficit
Motor deficit
Autonomic deficit
Combination
CLINICAL PRESENTAION

14. CLINICAL PRESENTAION Requires high index of suspicion
Overdiagnosis is better than underdiagnosis
In axonotmesis early intervention is directly related to the prognosis
Positive Tinnels’s test indicate urgent surgery

15. WORK UP

16. Surgical causes of compression
MANAGEMENT
Observation:
Neurobraxia
Axonotmesis
Surgical repair
Neurotmesis
Surgical causes of compression
Nerve grafting
Wide gap
Segmental loss

17. PROGNOSIS