brachial plexus injury its localization and management

1. BRACHIAL PLEXUS INJURY,
LOCALIZATION AND ITS
MANAGEMENT
DR. AJAY KUMAR SINGH
DNB RESIDENT
NEUROSURGERY
VPIMS

2. DEFINITION: A union of the ventral rami of the lower four cervical
nerves and the greater part of the first thoracic ventral ramus.

3. PREFIXED: When the branch from C4 is large, that from T2 is frequently absent and
the branch from T1 is reduced.
POSTFIXED: If the branch from C4 is small or absent, the contribution from C5 is
reduced, that from T1 is larger and there is always a contribution from T2.

4. The C5 and C6 rami unite
at the lateral border of
scalenus medius as the
upper trunk.
The C8 and T1 rami join
behind scalenus anterior as
the lower trunk.
The C7 cervical ramus
becomes the middle trunk.

5.  The three trunks incline
laterally, and either just
above or behind the
clavicle, each bifurcates
into ant and post
divisions.
 The ant divisions of the
upper and middle trunks
form a lateral cord that
lies lateral to the axillary
artery.

6.  The ant division of the
lower trunk descends at
first behind and then medial
to the axillary artery and
forms the medial cord,
which often receives a
branch from C7 ramus.
 Post divisions of all three
trunks form the post cord,
which is at first above and
then behind the axillary
artery.

7.  Roots and trunks lie in the supraclavicular space.
 The divisions are located posterior to the clavicle.
 While cords and branches lie infraclavicularly.
 All three cords of the plexus lie above and laterally to the
medial portion of axillary artery.

8. Supraclavicular/Branches from Roots
1) Scalene and longus
colli (C5 – C8)
2) Long thoracic nerve
(C5 – C7)-Serratus
anterior
3) Dorsal scapular
nerve (C5)-
Rhomboids major,
Levator scapulae
4) Branch to phrenic
nerve ( C5)

9. Branches from trunk
Only from Upper trunk
 Suprascapular nerve –
to Supraspinatus and
Infraspinatus ( C5 )
 Nerve to the
Subclavius
muscle(C5)
Lower trunk - close
relation to subclavian
artery and apex of
lung.

10. Post to clacvicle/Divisions
 Retroclavicular
 No direct branches from divisions
 Anterior divisions – supply mostly flexor muscles
 Posterior divisions - extensors.

11. Infraclavicular/Cords
Lateral cord
 Union of anterior
division of upper and
middle trunk -- C5, C6
, C7
 L - Lateral pectoral
nerve
 M- Musculocutaneous
(cb,b,br)
 L - Lateral head of
median nerve.

12.  Lateral cord – contains
C6, C7 sensory
C5 – C7 motor
 No C5 sensory fibres pass through lateral cord.
(C5 sensory – posterior cord)

13. Posterior cord
 Union of posterior divisions of all three trunks (C5, C6, C7
sensory and C5 – C8 motor).

14. Branches of posterior cord
U – Upper subscapular
L - Lower subscapular
N – Nerve to latissimus
dorsi
A – Axillary nerve
Deltoid and teres minor)
R – Radial nerve

15. Medial cord
 C8, T1 motor and
sensory
 Anterior division
of lower trunk
 M – Medial
brachial and
antebrachial
cutaneous nerve
 M - Medial
pectoral nerve
 M - Medial head
of median nerve
 U - Ulnar nerve

16. Terminal nerves
 Formed in the distal axilla
 Mainly 3 – Median, Ulnar and Radial
 Only median arises from more than one cord.

18. Dermatomes
 C5 – Lateral arm
 C6 – Lateral forearm, thumb, index finger
 C7 – Posterior forearm, middle finger
 C8 – Medial forearm, ring and little finger
 T1 – Medial arm

19. MYOTOMES
 C5 – Shoulder abduction
 C6 – Elbow flexion or wrist extension
 C7 – Elbow extension or wrist flexion
 C8 – Grip strength, shake hands
 T1 – Interosseii, spread fingers and resist finger adduction

22.  From the clinical examination and functional point of
view, the C5 and C6 roots are for shoulder and elbow
functions and C8 and T1 for hand and forearm functions.
 C7 contributes to shoulder, elbow and hand functions.
 In other words, C7 has considerable cross-innervations
with C5, C6 and C8. Because of this cross-innervation, no
single muscle is innervated by C7 alone.
 Therefore, C7 transection will cause minimal muscle
dysfunction which is compensated very quickly.

23. Epidemiology
 Just over half of all adult brachial plexus injuries occur between
the ages of 19 and 34 years old.
 Narakas rule of "seven seventies“ :
1. Approximately 70% of traumatic BPI are secondary to motor
vehicle accidents; of these,
2. Approximately 70% involve motorcycles or bicycles.
3. Of the cycle riders, approximately 70% have multiple injuries.
4. Overall, 70% have supraclavicular lesions;
5. Of these, 70% have at least one root avulsion.
6. At least 70% of patients with a root avulsion also have
avulsions of the lower roots (C7, C8 or T1).
7. Finally, of patients with lower root avulsion, nearly 70% will
experience persistent pain.

24. ETIOLOGY
 Mechanical: positioning, obstetric, tumor growth, infection,
aneurysm, posttraumatic.
 Metabolic: Diabetes
 Infectious: herpes simplex, Dengue virus, hepatitis E, or
herpes zoster.
 Immunologic: influenza, hepatitis B, smallpox, HPV.
 Pharmaceutical: Infliximab, cisplatin or vinblastine
 Radiation therapy
 Neoplastic cause

25. Mechanism of Nerve Injury

26. A. Traction
B. Percussion
C. Cervical Nerve Compression

27. Sunderland classification
Grade 1: Neuropraxia
 Conduction disruption with intact axon
Grade 2: Axonotmesis
 Disrupted axon with intact endoneurium; Wallerian degeneration
takes place after 1-2 weeks
Grade 3: Neurotmesis with preservation of perineurium
 Endoneurium is disrupted
Grade 4: Neurotmesis with preservation of epineurium
Grade 5: Neurotmesis with complete transection of nerve trunk

28. Classification of Brachial plexopathies
1) Supraclavicular(root and trunk) –
Upper plexopathy (upper trunk and root)
Middle plexopathy (middle trunk & root)
Lower plexopathy(lower trunk and root)
2) Retroclavicular (division)
3) Infraclavicular(cords and nerves)

30. Preganglionic and postganglionic
 In case of a preganglionic injury, the nerve is avulsed from spinal
cord, separating motor neurons from the motor centers of the
ventral horns of the spinal cord.
 Preganglionic lesions are not repairable and alternative working
motor nerves need to be transferred.
 Contrarily, postganglionic lesions may be restored spontaneously
or may be repaired surgically.
Pre-ganglionic injuries
 • Spinal roots are avulsed from the spinal cord
 • Loss of motor function only
Post-ganglionic injuries
 • Occur distal to the dorsal root ganglion
 • Loss of both sensory and motor functions.

33. Clinical evaluation
 If trauma - what was the arm position on impact?
Arm by side of body – C5, C6
Arm parallel to ground – C7
Arm above shoulder – C8 T1

35. Principles of Localization
Certain sites are prone to nerve entrapments/injuries
 Nerve opposing bone
---Ulnar nerve at the elbow
 Closed spaces
---Carpal tunnel
 Adjacent structures
---Median nerve at the elbow, adjacent to the brachial
artery

36. Upper Lesions of the Brachial Plexus (Erb’s
Palsy):
 Resulting from excessive displacement of the head to
opposite side and depression of shoulder on the same
side.
 This causes excessive traction or even tearing of C5
and C6 roots of the plexus.

37. Effects:
Motor: paralysis of
 Supraspinatus,
 Infraspinatus,
 Subclavius,
 Biceps brachii,
 Part of brachialis,
 Coracobrachialis;
 Deltoid
 Deres minor.
Sensroy: sensory loss on the lateral side of the arm.

38. Deformity:
 Waiter tip postion
 Limb will hang by
the side,
 Medially rotated
 Pronated forearm
(biceps paralysis)

39. Lower Lesions of the Brachial Plexus
(Klumpke Palsy)
 Traction injuries by excessive abduction of the arm i.e.
occurs if person falling from a height clutching at an object
to save himself or herself.
 Can be caused by cervical rib.
 T1 is usually torn (ulnar and median nerves)

40.  Motor Effects: paralysis of all the small muscles of the
hand.
 Sensory effects: loss of sensation along the medial side
of the arm.
 Deformity: claw hand caused by hyperextension of the
metacarpophalangeal joints and flexion of the
interphalangeal joints.

41. Axillary Nerve injury
Causes:
 Crutch pressing upward into the armpit,
 Downward shoulder dislocations
 Fractures of the surgical neck of the humerus.

42.  Motor effects:
 Deltoid paralysis
 Teres minor paralysis.
Sensory effects:
 loss of sensation at lower of deltoid
Deformity:
 Wasting of deltoid

43. Radial Nerve injury
Injury in axilla :
 Crutch pressing up into armpit
 Drunkard falling asleep with one arm over the back of a
chair.
 Fractures of proximal
humerus.

44. Motor effects: paralysis of
 Triceps, Anconeus, Extensors of the wrist, Extensors of
fingers, Brachioradialis, Supinator muscle.
 Deformity: Wrist and finger drop
Sensory effects :
 Small area of sensation loss at arm and forearm
 Sensory loss over lateral part of the dorsum of the hand
(lat. 3.5 fingers without distal phalanges)

45. Median Nerve Injury
Motor effects: paralysis of
 pronator muscles
 long flexor muscles of the wrist and fingers,
Exception:
 Flexor carpi ulnaris
 Medial half flexor digitorum profundus.

46. Deformity:
 apelike hand
 Thenar muscles wasted
 Thumb is laterally rotated and
adducted.
 Index and to a lesser extent the
middle fingers tend to remain
straight on making
 Weakening of lat. 2 fingers
Sensory:
 Sensory loss on the lat. 3.5 fingers
on palmar side
 Sensory loss over distal phalanges
of lat. 4 fingers on dorsal surface

48. Ulnar nerve injury
Motor effects: paralysis of
 Flexor carpi ulnaris
 Medial half of the flexor digitorum profundus
 All interossei, and 3-4 lumbricals
loss of abduction and adduction of fingers, wasting of hypothenar
 Deformity:
 Partial claw hand
Sensory effects :
 Sensory loss over 1.5 fingers on both surfaces

50. THANK YOU

51. INVESTIGATION
 Serial needle electromyography (EMG)
 Nerve conduction velocity (NCV) studies
 CT myelograms
 Magnetic resonance myelography (MRM).
 To be performed prior to brachial plexus exploration.
Typically, the first EMG and NCV are performed 6 weeks
following trauma, and the second EMG / NCV studies are
performed 3 to 4 months after injury if indicated.
 If no progress is identified on the EMG / NCV or during
physical examination, then a CT myelogram or MRM is
obtained and plexus exploration is performed.

52. Electromyography (EMG)
 Electromyography (EMG) tests muscles at rest and during activity.
 Denervation changes (fibrillation potentials) can be seen as early as
10 to 14 days after injury in proximal muscles and as late as 3 to 6
weeks in distal muscles.
 The presence of voluntary motor unit potentials with limited
fibrillation potentials signifies better prognosis.
 Early signs of muscle recovery: occurrence of nascent potentials,
decreased number of fibrillation potentials, appearance of or an
increased number of motor unit potentials).
 These signs contribute to expected clinical recovery in weeks or
months.

53. Nerve Conduction Velocity (NCV)
 Is used initially as a screening test for the presence or
absence of conduction block.
 Assesses both motor and sensory function via a voltage
stimulator applied to the skin over different points of the
nerve to be tested.
 The evoked response is recorded from a surface electrode
overlying the muscle belly (motor response) or nerve
(sensory response).

54. Current advances
 Neurography
 Coronal oblique volumetric MRI
 CISS (Constructive interface in steady state)
 Fast imaging employing steady-state acquisition (FIESTA)

55. Management
 Conservative v/s operative
 Timing of surgery

56. Timing of surgery
Acute exploration
 Open injury with sharp laceration
 Concomitant vascular injury
 Crush and contaminated wound
Early exploration (1 – 2 weeks)
 unequivocal complete C5- T1 avulsion injury
Delayed exploration (> 3 months)
 Recommended for complete injuries with no recovery by clinical
examination or EMG at 12 weeks post injury candidates showing
distal recovery without regaining clinical or electrical evidence of
proximal muscle function

57. Treatment options
 Neurolysis
 Nerve repair
 Nerve graft
 Nerve transfer (neurotization)
 Nerve root replantation
 Free muscle and tendon transfer

58. Concepts of upper arm type BPI reconstruction
 The nerve begins to regenerate, around 1-1.5 mm daily.
 The motor endplates with which the nerve communicates will
eventually cease to function in 12-18 months.
 If a proximal plexus injury occurs, then the regenerated nerve
may not reach the motor endplate in time to be effective.
 Therefore, using the nerve transfer technique of harvesting nerve
fascicles from uninjured nerve and transferring to the injured
nerve (close-target neurotization) may facilitate the salvage of
critical motor endplates and their corresponding muscles.

60. Recent advances
 Direct ventral intraspinal implantation
 Sutureless repair
 Stem cells
 Synthetic Nerve grafts