Peggers’ Super Summary of Brachial Plexus and Nerve Injuries

2nd degree
o Axontmesis
o Endoneurium preserved
o Regeneration is complete or near
complete
 3rd degree
o Endoneurium disrupted
o Perineural sheaths intact
o Fibrosis can limit recovery
th
 4 degree
o Only epineurium intact
o Internal damage is severe
o No recovery unless segment replaced
 5th degree
o Nerve divided
Anatomy:
 Nerves are bundles of axons conducting impulses.
o Efferent are motor
o Afferent are sensory
 An axon is an extension of a
neuron or nerve cell.
 Cell bodies of the motor
neurons are clustered in the
anterior horn of the SC.
 Myelin sheath contains
Schwann cells and bare areas
called nodes of ranvier.
 CT covering the schwann cells is the endoneuium.
 Axons make up nerve fascicles, these are covered
by perineurium.
Types of Injuries: (Eponymous names)
 Seddon’s Description
o Ischaemia
o Neuropraxia
o Axonotmesis
o Neurotmesis
 Sunderland Classification (many cases fall between
axonotmesis and neurotmesis)
o 1st degree
o 2nd degree
o 3rd degree
o 4th degree
o 5th degree
Nerve Injury Classification:
Seddon’s Description
 Ischaemia
o Tingling within 15mins, loss of pain after
30mins and weakness after 45 mins. Full
recovery seconds to minutes
 Neuropraxia
o Segmental demyelination from
compression.
o Full recovery possible
 Axonotmesis
o Loss of conduction nerve in continuity
o Distal to lesion axons disintegrate aka
Wallerian degeneration
o Axonal growth is 1-2mm / days
 Neurotmesis
o Nerve devision
o Endoneurial tubes destroyed and scarring
prevents axonal regeneration.
Sunderland’s Classification
 1st degree
o Transient ischaemia or neuropraxia
o Reversible
“Double Crush” Phenomenon
NB: Proximal compression as found in cervical spondylosis
can make distal nerves more ‘sensitive’ thus increasing risk
of carpal tunnel as an example.
Brachial Plexus Classification:
1. Open vs Closed
a. CLOSED – Traction
b. CLOSED – Crush
(Causes:
Thoracic outlet syndrome
Pancoast’s tumour
Radiation
Vasculitis
Metabolic insults)
2. Supraclavicular or infraclavicular
a. SUPRACLAVICULAR
i. Preganglionic – avulsions
No wallerian degeneration
occurs within the sensory fibres
– ie sensation preserved
ii. Postganglionic – ruptures
Both sensory and motor
degeneration occurs
b. INFRACLAVICULAR
i. Postganglionic ONLY
When to operate:
 Open Injuries
 Vascular compromise
 Compartment syndrome
 Severe open fractures or Contaminated wounds
 Complete loss of motor/sensory/sympathetic tone
distal to injury ie grade 3-5 (NB loss of nerve
conduction distal to injury AFTER 72 hrs suggests
Sunderland grade 2)
 Failure of progression of Hoffman-Tinel tap test
suggests 4-5th degree injury (tap both injury site
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Peggers’ Super Summary of Brachial Plexus and Nerve Injuries

and distally at regeneration point should produce
tingling sensation)
TRACTION INJUIRES CONTRAVERSIAL
ADVANTAGE
o End of surgery patient has clear idea of
prognosis
o Early surgery little fibrosis which can start
as early as 10 days – so operatively easier.
DISADVANTAGE
o Treatment of a lesion destined to recover
o Leave an irrecoverable lesion untreated
Examination Findings:
 Features of Root avulsion (irreparable)
o Crushing or burning pain in an anaesthetic
hand
o Paralysis of diaphragm
o Horners syndrome (ptosis, small pupil,
unequal eye size)
o C spine injury of hyper-reflexia
o More likely to have vascular injury
 Upper plexus injuries more much more common
(C5/6)
o Weakness in shoulder abductors, external
rotators and forearm supinators
 Pure lower lesion plexus injuries are RARE
o Wrist and finger flexors are weak &
paralysis of intrinsic hand muscles
o Sensation lost in ulnar forearm and hand
 Preservation of rhomboids (dorsal scapular nerve),
serratus anterior (long thoracic nerve),
supraspinatus (suprascapular), but loss of biceps
(musculocutaneous), triceps (radial) and deltoid
(axillary) suggest lateral and posterior cord
injury
 Root avulsion from supraclavicular fossa may have
absence of Hoffman-Tinel tap test.
 Hoffmann-Tinels tap test will be present in Root
Rupture.
 Horner’s Sign in T1 nerve root avulsion
 Vascular Status
 NB compartment syndrome may be masked by
insensate limb
Investigations:
 Immediate investigations
o ATLS
o CXR
 Phrenic nerve injury Root
avulsion likely) = raised
hemidiaphragm.
 Clavicular, ribs or scapular injury
 Early Investigations
o MRI / CT myelography for intradural
rootlet ruptures or pseudomeningocoeles –
suggests root avulsions
o A positive MRI/CT in first few days is
unreliable – the dura can be torn without
root avulsion
 Delayed Investigations > 6 Weeks
o Nerve conduction will highlight where
compression is occurring
 Preservation of SNAP – sensory
nerve action potentials = avulsion
preganglionic injury and poor
prognosis
o Electromyography (EMG) may show
subclinical abnormal AP or fibrillation in
cases of severe nerve damage
 Electromyography shows
fibrillation potentials consistent
with neuropraxia
Simplified Mx options:
Non surgical
 Neuropraxia / Sunderland 1
 Axonotmesis / Sunderland 2
6 Months observation +/- Surgical exploration
 Sunderland 3
Surgical exploration
 Sunderland 4-5 (5 = Neurotmesis)
 Sunderland 6 = mixed histological patterns
Surgical Repair Methods:
NB Direct nerve repair is hardly ever possible. Options are
as follows;
1. Nerve Grafting
2. Intraplexual nerve transfers
3. Neurolysis – of doubtful value
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