Brachial plexus injuries account for 1% of trauma presentations and are commonly caused by stretch or contusion injuries. Surgical treatment options depend on the severity and location of injury, with the goal of restoring functions like elbow flexion and shoulder stability. Nerve grafts and transfers are used to reinnervate muscles, with transfers preferred when possible due to shorter regeneration distance. Outcomes depend on mechanism and timing of surgery, with dual nerve transfers potentially allowing over 90 degrees of shoulder abduction.

1. Brachial Plexus and Its Injury
Dr. Hari Poudel
M.Ch(Neurosurgery) Resident

2. Brachial Plexus and its injury
• Brachial plexus injuries -1/3 rd of peripheral
nerve injuries, seen in 1% of patients
presenting to trauma
• median age of 34
• males are affected more frequently

3. • 1019 brachial plexus lesions
– stretch or contusion (50%)
– thoracic outlet syndrome (16%) and
– nerve sheath tumors (16%)
– Gunshot wounds (12%) and
– lacerations (7%)
• Kim DH, Cho YJ, Tiel RL, et al. Outcomes of surgery in 1019 brachial plexus lesions treated at
Louisiana State University Health Sciences Center. J Neurosurg. 2003;98:1005-1016.

4. ANATOMY

6. Spinal nerves and trunks are supraclavicular,
divisions behind the clavicle
Lateral, posterior, and medial cords are
infraclavicular

7. Brachial Plexus Injury
• Introduction
– functional recovery after nerve injury
• degree of nerve regeneration and the appropriate
reinnervation of viable receptors
• time interval between trauma and reconstruction,
• level of injury
• mechanism of injury,
• type of repair, and
• age of the patient

8. • Nerve surgery is designed to
– restore continuity of the nerve or its components
– provide the optimal setting for regeneration of
the nerve and recovery of function

9. • The most serious injury is that in which one or
several spinal nerves have been avulsed from
their insertion to the spinal cord.

10. • Surgical treatment of Brachial Plexus injury
– end-to-end nerve neurotization
– interpositional nerve grafting
– intraplexal/extraplexal nerve transfer
– neurolysis alone

11. • Secondary surgery
– free muscle transfer
– tendon transfers
– muscle/tendon releases

12. Brachial Plexus: Pathology
• predominantly stretch or compressive in
nature sharp laceration
• concussive forces secondary to a high-velocity
projectile

13. • The greater is the risk of avulsion injury
– the more violent the trauma and the more the forces are in line
with the spinal nerve at the foraminal level
• C5, C6, and C7 SNs have fibrous attachments of the
epineurium to the cervical transverse process
– provide additional protection against avulsion
• C8 and T1 SNs does not have such attachments
– explain the higher incidence of their avulsion
• C5,C6 SNs sustain a higher incidence of rupture at the
transverse process

14. • Compression injuries to the Brachial Plexus
– between the clavicle and the first rib
– often associated with fracture of the clavicle
• Nerve laceration can involve
– any portion of the cross sectional anatomy of the nerve
– can result in separation of the proximal and distal portions
• Partial nerve injuries are more common than complete
lesions
– often consist of a spectrum of injuries to the nerve

15. Pathophysio
• at first degenerative and later regenerative
• Anatomic rupture begins with
– the axon or its coverings
– continues with basal membrane, endoneurium, and
perineurium
– ends at the epineurium

16. Classification

18. • Sunderland Grade I: Neurapraxia
– Myelin overlying the nodes of Ranvier become
distorted, which leads to focal conduction block
without wallerian degeneration

19. • Sunderland Grade II injury:
– Moderate nerve injuries interrupt the axon’s
continuity and result in wallerian degeneration but
leave the basal lamina tubes intact
– Because the neural connective tissue structures
remain intact, the potential for spontaneous
regeneration is retained
– However, time for recovery depends on the distance
the axons have to regenerate from injury site to
target

20. • Sunderland grade III injury:
– the endoneurium is also interrupted, and the
potential for spontaneous regeneration is greatly
reduced
• Sunderland Grade IV injury:
– Perineurium surrounding the fascicle is also
disrupted, the internal fibrosis occurs
– little spontaneous regeneration is anticipated

21. • Sunderland Grade V injury:
– Complete rupture of the nerve, including the
epineurium, or neurotmesis, with no hope for
spontaneous recovery

22. • upper plexus palsy-waiter’s tip
• lower plexus palsy claw hand
• pan-plexus palsy -flail arm.

24. • These lesions are often mixed, and
neurapraxia and axonotmesis may coexist
• Similarly, the severity of injury may vary
across fascicles in an injured nerve

25. Pathophysiology
• Preganglionic injuries involve the nerve roots;
• Sites-level of the foramen, intradural avulsion
of the spinal rootlets
• distal sensory axon with the cell body is
maintained
• The time course of any recovery can give an
indication of severity of injury

26. • Fractures of the bony spine can be associated
with spinal nerve
• or root injury
• Evaluation of both passive
• and active range of motion of the joints may
reveal contractures
• that necessitate management

27. Differentiating preganglionic from
postganglionic injuries
• Horner’s syndrome: pre-ganglionic injury
interrupts white rami communicantes
• paralysis of serratus anterior
• paralysis of rhomboids (dorsal scapular nerve)
• early neuropathic pain suggests nerve root
avulsion.
• MRI or myelogram will show
pseudomeningoceles at the avulsed levels

28. • MRI or myelogram will show
pseudomeningoceles at the avulsed levels
• EMG: requires ≥ 3 weeks
– denervation potentials in paraspinal muscles
– normal SNAP: normal SNAP can be recorded
proximally even in an anesthetic region
• 6

29. • pseudomeningocele : nerve root avulsion
• However 15% of pseudomeningoceles are not
associated with avulsions, and 20% of
avulsions do not have pseudomeningoceles

30. • rhomboid and serratus
anterior muscle function
is preserved, external
rotation of the shoulder
(infraspinatus muscle)
and first 30 degrees of
shoulder abduction
(supraspinatus muscle)
are lost, the injury is
distal to the spinal nerve
and in the upper trunk.

31. • medial pectoral nerve
-sternal head of the pec
maj
• lateral pectoral nerve
innervates the
clavicular head.
• Atrophy of this muscle
indicates a severe pan-
BP injury.

32. • “trick” movements
• Steindler effect : wrist extensor group that
cross both wrist and elbow- can produce some
elbow flexion with the hand pronated and
without any use of the biceps

33. • Bernard-Horner sign
highly indicative of
avulsion of C8 and T1
• false-negative finding is
more
common than a false-
positive finding
• may not be present
during the first 48 hours
after injury and can also
fade over time.

34. Tinel’s sign
• Regenerating nerve fibers develop
mechanosensitivity.
• Percussion over the course of the nerve
produces tingling paresthesia in the sensory
distribution of the nerve

35. • percussion starting distally and progressing
toward the lesion site,
• tingling is perceived as soon as the frontal tip
of the downgrowing fibers, which are highly
sensitive but not yet myelinated

36. Associated Injuries
• fracture of the tip of a lower cervical
transverse vertebral process
• Orthopedic injuries
• Hemidiaphragm paralysis indicates a proximal
C5 lesion

37. • Damage to the spinal cord with long tract
neurological signs have been established in
12% of cases of a complete BP injury

39. Electrodiagnostic studies
• Preoperative
– how far proximal or medial the injury extends
• intraoperative evaluations

40. • 2 weeks: wallerian degeneration- trophic
influence of nerve on muscle is lost
• denervation potentials (positive sharp waves
and fibrillations on electromyography

41. • Recruitment of motor units is reduced in
axonal injury
•
• However the presence of motor units under
voluntary control indicates a nerve in
continuity and a good prognosis

42. • Reinnervation potentials (nascent motor
units, polyphasic action potentials) appear in a
muscle several weeks in advance of clinical
evidence of recovery

43. MRI
• as early as 4 days after injury
• 2 weeks before EMG changes
• Hematoma and vascular injury

44. • In the acute situation, an MRI can visualize a
hematoma
• and document a vascular injury.
• Preoperative diagnosis of a preganglionic or
root avulsion injury indicates the need for
early surgery and use of nerve transfers

45. Therapy/Management
• nonoperative care
• appropriate selection of surgical candidates,
• timing of surgery,
• priorities regarding surgical targets, and
• method of nerve repair

48. • Surgery - risks of waiting outweigh risks of
going ahead with surgery

49. • The treatment of lesions of the brachial plexus
has changed from shoulder fusion, elbow
bone block, and finger tenodesis following
World War II to far greater functional
restoration made possible by advances in
nerve repair and microsurgery

50. Nonoperative care
• Maintaining ROM,
• aggressive stretching program

51. Immediate Surgery
• sharp laceration-
• evidence of avulsion or a Sunderland grade V
injury (rupture)
• Associated vascular injury

52. Sunderland grades II to III injury
• observed for a period of 3 to 4 months
• undergoing serial examination for signs of
regeneration, including an advancing Tinel’s
sign or EMG changes

53. • early surgery
– Less scarring.
– allow visual inspection of the
– prediction of outcome with or without nerve
repair
• Primary and Secondary Surgery

54. Priorities
• Elbow flexion
• Shoulder stability
• wrist extension
• finger flexion
• wrist flexion
• finger extension

55. • Restoration of intrinsic hand function
• distal nerve transfers (brachialis nerve to
median AIN)

56. NERVE NEUROMA
• Resection and Grafting verses Transfer
• Compound Nerve action Potential- across
• small amplitude and slow Conduction – recovery
will occur after neurolysis
• postganglionic injury - does not show evidence
• of recovery -repaired.
• Resection and end to end coaption or cable graft

57. Surgical Exposures
• Supraclavicular
Exposure:
• parallel and superior to
the clavicle at the base
of the lateral cervical
triangle.
• omohyoid muscle is
seen crossing obliquely-
marking the upper
border of the exposure

59. • upper trunk -lateral
border of the anterior
scalene muscle.
• anterior scalenectomy-
easier identification of
the middle and lower
trunk

60. • long thoracic nerve
-protected during
dissection around the
C6 nerve and upper
trunk

61. suprascapular nerve
• lateral side of the upper
trunk follows slightly
oblique craniocaudal
course to the scapular
notch
• omohyoid muscle
inserts on the edge of
the notch, providing a
guide when scarring
makes it difficult to
expose the nerve

62. Supraclavicular approach
• limited inspection of spinal nerves C-8 and T-1
and the inferior trunk

63. Access to Spinal Accessory
• extended laterally over
the anterior edge of the
trapezius -accessory
nerve.
• spinal accessory nerve
passes deep to the
anterior border of
thetrapezius
muscle,approximately 3
cm rostral to the clavicle.
• Stimulation

64. Infraclavicular Exposure
• Deltoidpectoral Groove
• pectoralis major muscle can be divided

65. • lateral cord -first cord
to be identified
• Lateral
• and deep to the lateral
cord, the posterior cord
• subclavian artery is
palpated and identified
• Trace all M

66. • Musculocutaneous nerve -direct rupture from
the biceps brachii
• Clavicle transection: Rarely-vascular

67. • lateral cord often
divides into
musculocutaneous
median nerves,
• posterior cord divides
into the axillary nerve
and radial nerve deep
to the coracoid process

68. Posterior Exposure
• expose the juxtaforaminal portion of the
spinal nerves
• Position: prone
• parascapular incision
• Trapezius and rhomboid muscles sectioned.
Paraspinal muscles are retracted, and
resection of the first rib and scalene muscles
exposes the proximal spinal nerves

69. • Facets-removed to allow visualization of the
spinal nerves intraforaminally
• tumors of the C8 and T1 nerve roots or lower
trunk.

70. Surgery in Brachial Plexus Repair-
Nerve Grafting
• resection of a neuroma
• repair by interposing nerve grafts
• function of the graft = nerve segment distal to
the lesion site-provides physical guidance to
outgrowing axons and production of
neurotrophic factors

71. • Drawback-involvement of two coaptation
sites that must be crossed by the axons
• chances that axons could be misdirected are
doubled.
• fascicles of the graft are closely packed-
chances that axons will enter basal lamina
tubes instead of interfascicular tissue

72. Nerve Transfer
• functioning donor nerve is divided
• proximal end is coapted to the denervated
distal target nerve
• repair site closer to the target - time for
regeneration is shorter and the prognosis is
better

73. • restoration of shoulder function and elbow
flexion
• reasonable to consider nerve transfer to
shorten time to reinnervation
• When a nerve transfer is performed, plasticity
is still needed in the nervous system

74. • Functional restoration after nerve transfer
requires adaptation of the central nervous
system to execute the new task properly
• whether repair as close to the target muscle
as possible outweighs the importance of
restoring the original wiring plan.

75. shoulder function
• spinal accessory nerve
• Triceps nerve branch elbow flexion,
intercostal nerves, an ulnar or
• median fascicle, the thoracodorsal nerve, or
the medial pectoral
• nerve is used

76. • the ipsilateral and contralateral C7 nerves
have been used as donor nerves

77. Shoulder Function
• Spinal Accessory Nerve.
• 1500 myelinated axons
• Suprascapular, musculocutaneous nerve.
• Direct end-to-end transfer of the spinal
accessory nerve to the suprascapular nerve.

78. Triceps Nerve Branch
•Recipient: axillary nerve anterior division of the
axillary nerve or more proximal on the main
axillary nerve
•Donor nerve -long head, lateral head, or medial
head of the triceps muscle.
•Removal of a single triceps branch does not
sacrifice elbow extension

79. • Dual transfers-targeting suprascapular and
axillary nerve
• Patients who have undergone dual transfers
can achieve 90 degrees or more of shoulder
abduction

80. Elbow Flexion
• Intercostal Nerve: 1200 axons.
• two to four nerves
• often T3, T4, and T5 because these can be
mobilized for an end-to-end transfer to the
musculocutaneous nerve

81. Fascicles of the Ulnar and Median
Nerve
• Transfer of a single fascicle of the ulnar nerve
to the -Oberlin
• M4 or better strength of elbow flexion with
dual transfers for elbow flexion can be
obtained.

82. Contralateral C7
• complete C7 or the posterior portion is
coapted –injured BP
• useful in children, but adults lack the neural
plasticity

83. Novel Nerve Transfer
• gracilis muscle can be harvested with
microanastomosis
• Ulnar nerve fascicle, the spinal accessory
nerve or intercostal nerve can serve as donor
to the free muscle.

84. Late surgery
• ulnar nerve fascicle transfer to the biceps
branch- superior To grafts

85. Neuropathic pain
• anticonvulsant with a narcotic can be used for
severe pain
• the pain often resolves as regeneration
completes with innervation of targets
• Avulsion of nerve roots
• approximately 50% of patients are pain free or
able to cope with their pain within 1 year after
surgery

86. BIRTH-RELATED INJURIES OF THE
BRACHIAL PLEXUS
• Timing of and Selection for Surgery:
• traction
• Neurotmesis and root avulsion result in
permanent loss
• 20% to 30% with a poor prognosis

87. • Paralysis of the biceps muscle at age 3 months,
especially with wrist drop-poor prognosis
• Magnetic resonance neurography is
• often helpful in this situation because it can
clearly distinguish
• loss of continuity from stretch, can provide a
progressive view of
• neuroma formation, and distinguish terminal
neuroma from
• neuroma in continuity

88. • Impaired hand function -absolute indication as
soon as the infant turns 3 months of age

89. Secondary Procedures for Brachial
Plexus Injuries
• Additional function can be augmented or
provided by
– muscle or tendon transfers
– bone arthrodesis (causing the fusion of a joint)
– soft tissue reconstruction

90. • delay -when nerve reconstruction was
deemed too late to warrant an expectation of
reasonable functional outcome
• previous procedures such as neurorrhaphy,
nerve grafting, or nerve transfer and recovery
produced unsatisfactory results