nerve injury

Nerve injury

Hamad emad dhuhayr

Dr Saleh WaslAllah Alharby

www.ksu.edu.sa/DrSalehAlharby

OUTLINE

DEFINITION. TYPES OF NERVE INJURIES. FATE (pathophysiology) AND

REHABILITATION. ETIOLOGY. PRESENTATION. DIAGNOSIS. CLINICAL EXAMPLES: (ERB’S,CARPAL TUNNEL,RADIAL,ULNAR,SCIATIC AND

PERONEAL N.)



DEFINITION

Partial or complete interruption of normal physiology of the nerve.

NERVE CONDUCTION IS AFFECTED.



Classification Of Nerve Injuries

Seddon, Sunderland and lately by Mackinnon

6 degrees

Degrees Of Nerve Injury

1st degree of injury(neuraparaxia)

Segmental demylination

Axons intact

Recovery in 12 to 16 wks

2nd degree injury(axonotmesis)

Axonal injury/ distal wallerian degeneration

Regeneration at rate of 1 inch per month

Complete slow recovery


3rd degree injury Axonal injury & fibrosis of endoneurium Incomplete recovery

4th degree injury Axonal injury Damage to endo and perineurium with

dense scarring Needs surgical intervention


5th degree injury(neurotmesis) Complete nerve division

6th degree injury Variable combination of previous

five degrees of nerve injury

FATE AND REHABILITATION

WALLERIAN DEGENERATION

1 MM PER DAY



REHABILITATION

PAIN CONTROL.

SPLINT. (AVOID PRESSURE SORES) NERVE AND MUSCLE STIMULATION.

NEARBY JOINTS RANGE OF MOTION.

MONTHS ----- YEARS .



Nerve Injury

Focal contusion (gunshot wounds) Stretch/traction injury Drug injection injury Compression Crush injuries Avulsion Laceration Electrical burns Idiopathic Others(Viral infections, metabolic and neural disorders)

PERSENTATION

PAIN LOSS OF SENSATION LOSS OF MOTION LOSS OF POWER LOSS OF REFLEXES WASTING TROPHIC CHANGES

(skin,sc,neurovascular,bones,muscles)

CONTRACTURES



DiagnosisDiagnosis

Motor functionMotor function

Movements, muscle atrophyMovements, muscle atrophy

sensory functionsensory function

Tinel sign, Ten testTinel sign, Ten test

Two point discriminationTwo point discrimination

Touch, vibrationTouch, vibration

•HistoryHistory•Examination Examination

Tinel Sign

Tinel sign: - peripheral tingling or

dysaesthesia' provoked by percussion of the nerve

Positive in axonal injuries

Electrical Stimulation Tests:

EMG

NCS

Intra operative nerve action potential

CLINICAL EXAMPLES

ERB’ PALSY

CARPAL TUNNEL SYNDROME(MEDIAN NV)

RADIAL NERVE INJURY

ULNAR NERVE INJURY

SCIATIC NERVE INJURY

LATERAL POPLITEAL NERVE INJURY



ERB’S PALSY

BIRTH INJURY (DIFFICULT LABOUR) TRACTION ON NERVE ROOTS C5-6 STRETCH-RUPTURE-AVULSION UPPER LIMB IN EXTENSION MOTHER NOTICE NO MOTION 90% GOOD RECOVERY ROLE OF SURGERY AFTER 3 MONTHS REMEMBER PROPER REHABILITATION



CARPAL TUNNEL SYNDROME

MEDIAN NERVE ENTRAPMENT BY FLEXOR RETINACULUM PAIN,NUMBNESS,NIGHT

MANUAL WORKERS

DIAGNOSIS

SURGERY



RADIAL NERVE INJURY



ULNAR NERVE INJURY



SCIATIC NERVE INJURY



PERONEAL NERVE INJURY (LPN)

FOOT DROP

TIGHT POP

SKELETAL TRACTION

DIRECT INJURY (RARE)

DYNAMIC SPLINT



Principals Of Nerve Repair

Microsurgical techniques

Adequate magnification

Microsurgical instruments & sutures

Different techniques:

Primary nerve repair

Nerve grafting

Nerve transfer

Nerve conduits

Nerve allografts

Timing Of The Nerve Repair

Sharply transected nerves

Immediate repair

Crushed, avulsed, blast injuries

Nerve ends tacked together

Repair delayed for 3 weeks or until wound bed permits

Re-exploration

Neuroma excision, nerve grafts

Acute nerve grafting in the 1st sitting

Bleeding control ,trimming of fascicles ,loose epineural suturing

Closed injuries treated expectantly for 12 weeks

Primary Nerve Repair

Primary nerve repair Epineural repair Grouped fascicular repair

Epineural Repair

Standard repair

Fascicular Repair

Restore the continuity of fascicles Internal topography Intra-operative nerve stimulation Neurolysis with the eyes Priority to the motor recovery(radial

and peroneal nerve)

e.g. Ulnar Nerve Fascicular Components

Nerve Grafts

Tension at site of repair

Need of postural positioning

Alignment of sensory & motor components

Maximize number of axons

Reversal of graft

Exclusion of expendable nerve

Options For Nerve Grafts

Sural nerve

30-40cm

Lateral peroneal communicating br : 10-20cm

Lateral antebrachial cutaneous nerve(LABC)

8cm

Medial antebrachial cutaneous nerve (MABC)

Anterior & posterior division

20 cm

Expendable nerves(peroneal and radial)

Sensory branches of ulnar and median nerves

Distal anterior interosseous nerve and so on…

Disadvantages

Donor site scarring Donor site sensory loss

Patient education

Neuroma In Continuity

Complete : resection and repair with graft

Neuroma In Continuity

Incomplete neuroma

Intra-operative nerve stimulation

Black boxing around neuroma

Nerve Transfer

Indications:

Very proximal peripheral nerve injuries

Root avulsions

Excessive scarring

Level of injury unclear

Idiopathic neuritides

Radiation induced nerve injury

Nerve Transfer

Motor nerve transfer

Pure motor axons

Close proximity

expendable

Synergistic supply

Sensory nerve transfer

pure sensory axons

Innervates non critical area

Expendable and lying in close proximity

Most Common Uses Of Nerve Transfer

elbow flexion

Shoulder abduction

Ulnar-innervated intrinsic hand function

Forearm pronation

Radial nerve function

Transfer of radial nerve to axillary nerve

Nerve Conduits

Veins, pseudo-sheaths, bioabsorbable tubes

short nerve gaps ≤ 3cm Low antigenicity , biodegradability Trials to add a nerve graft inside the

conduit neurotrophic factors

Nerve Allografts

Extensive injuries

Limited donor material

Immunosuppressive agents

FK506( tacrolimus )

Prednisone , azathioprine

Processed acellular cadaveric nerve allografts

AxoGen, Inc. ,Alachua, FL.

Summary

Axon degeneration occurs from mild compression injury

The prognosis for Neuropraxia is poor Axonotmesis is generally caused from

separation of the cell body from the neuron

Wallerian Degeneration typically does not occur in Neuropraxic injury

Surgical reconstruction is necessary in Neurotmesis

Wallerian Degeneration does not occur in Neurotmesis

A ligamentous structure can cause Neuropraxia



Refferences

Special surgery matary



Health & Medicine

nerve injury