Bracial plexus injury 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. ď‚— The three trunks incline laterally, and either just above or behind the clavicle, each bifurcates into ant and post divisions. ď‚— The ant divisions of the upper and middle trunks form a lateral cord that lies lateral to the axillary artery.
- 6. ď‚— 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. ď‚— Post divisions of all three trunks form the post cord, which is at first above and then behind the axillary artery.
- 7. ď‚— Roots and trunks lie in the supraclavicular space. ď‚— The divisions are located posterior to the clavicle. ď‚— While cords and branches lie infraclavicularly. ď‚— 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 ď‚— Union of anterior division of upper and middle trunk -- C5, C6 , C7 ď‚— L - Lateral pectoral nerve ď‚— M- Musculocutaneous (cb,b,br) ď‚— 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. ď‚— 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. ď‚— C7 contributes to shoulder, elbow and hand functions. ď‚— 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. ď‚— 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 ď‚— Mechanical: positioning, obstetric, tumor growth, infection, aneurysm, posttraumatic. ď‚— Metabolic: Diabetes ď‚— Infectious: herpes simplex, Dengue virus, hepatitis E, or herpes zoster. ď‚— Immunologic: influenza, hepatitis B, smallpox, HPV. ď‚— Pharmaceutical: Infliximab, cisplatin or vinblastine ď‚— Radiation therapy ď‚— Neoplastic cause
- 25. Mechanism of Nerve Injury
- 26. A. Traction B. Percussion C. Cervical Nerve Compression
- 27. Sunderland classification Grade 1: Neuropraxia ď‚— Conduction disruption with intact axon Grade 2: Axonotmesis ď‚— Disrupted axon with intact endoneurium; Wallerian degeneration takes place after 1-2 weeks Grade 3: Neurotmesis with preservation of perineurium ď‚— 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 ď‚— Nerve opposing bone ---Ulnar nerve at the elbow ď‚— Closed spaces ---Carpal tunnel ď‚— 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 ď‚— Supraspinatus, ď‚— Infraspinatus, ď‚— Subclavius, ď‚— Biceps brachii, ď‚— Part of brachialis, ď‚— Coracobrachialis; ď‚— Deltoid ď‚— Deres minor. Sensroy: sensory loss on the lateral side of the arm.
- 38. Deformity: ď‚— Waiter tip postion ď‚— Limb will hang by the side, ď‚— Medially rotated ď‚— Pronated forearm (biceps paralysis)
- 39. Lower Lesions of the Brachial Plexus (Klumpke Palsy) ď‚— 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. ď‚— Can be caused by cervical rib. ď‚— T1 is usually torn (ulnar and median nerves)
- 40. ď‚— Motor Effects: paralysis of all the small muscles of the hand. ď‚— Sensory effects: loss of sensation along the medial side of the arm. ď‚— Deformity: claw hand caused by hyperextension of the metacarpophalangeal joints and flexion of the interphalangeal joints.
- 41. Axillary Nerve injury Causes: ď‚— Crutch pressing upward into the armpit, ď‚— Downward shoulder dislocations ď‚— Fractures of the surgical neck of the humerus.
- 42. ď‚— Motor effects: ď‚— Deltoid paralysis ď‚— Teres minor paralysis. Sensory effects: ď‚— loss of sensation at lower of deltoid Deformity: ď‚— Wasting of deltoid
- 43. Radial Nerve injury Injury in axilla : ď‚— Crutch pressing up into armpit ď‚— Drunkard falling asleep with one arm over the back of a chair. ď‚— Fractures of proximal humerus.
- 44. Motor effects: paralysis of ď‚— Triceps, Anconeus, Extensors of the wrist, Extensors of fingers, Brachioradialis, Supinator muscle. ď‚— Deformity: Wrist and finger drop Sensory effects : ď‚— Small area of sensation loss at arm and forearm ď‚— 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 ď‚— pronator muscles ď‚— long flexor muscles of the wrist and fingers, Exception: ď‚— Flexor carpi ulnaris ď‚— Medial half flexor digitorum profundus.
- 46. Deformity: ď‚— apelike hand ď‚— Thenar muscles wasted ď‚— Thumb is laterally rotated and adducted. ď‚— Index and to a lesser extent the middle fingers tend to remain straight on making ď‚— Weakening of lat. 2 fingers Sensory: ď‚— Sensory loss on the lat. 3.5 fingers on palmar side ď‚— Sensory loss over distal phalanges of lat. 4 fingers on dorsal surface
- 48. Ulnar nerve injury Motor effects: paralysis of ď‚— Flexor carpi ulnaris ď‚— Medial half of the flexor digitorum profundus ď‚— All interossei, and 3-4 lumbricals loss of abduction and adduction of fingers, wasting of hypothenar ď‚— Deformity: ď‚— Partial claw hand Sensory effects : ď‚— Sensory loss over 1.5 fingers on both surfaces
- 50. THANK YOU
- 51. INVESTIGATION ď‚— Serial needle electromyography (EMG) ď‚— Nerve conduction velocity (NCV) studies ď‚— CT myelograms ď‚— Magnetic resonance myelography (MRM). ď‚— 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. ď‚— 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) ď‚— Electromyography (EMG) tests muscles at rest and during activity. ď‚— 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. ď‚— The presence of voluntary motor unit potentials with limited fibrillation potentials signifies better prognosis. ď‚— Early signs of muscle recovery: occurrence of nascent potentials, decreased number of fibrillation potentials, appearance of or an increased number of motor unit potentials). ď‚— These signs contribute to expected clinical recovery in weeks or months.
- 53. Nerve Conduction Velocity (NCV) ď‚— Is used initially as a screening test for the presence or absence of conduction block. ď‚— Assesses both motor and sensory function via a voltage stimulator applied to the skin over different points of the nerve to be tested. ď‚— The evoked response is recorded from a surface electrode overlying the muscle belly (motor response) or nerve (sensory response).
- 54. Current advances ď‚— Neurography ď‚— Coronal oblique volumetric MRI ď‚— CISS (Constructive interface in steady state) ď‚— Fast imaging employing steady-state acquisition (FIESTA)
- 55. Management ď‚— Conservative v/s operative ď‚— 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 ď‚— Neurolysis ď‚— Nerve repair ď‚— Nerve graft ď‚— Nerve transfer (neurotization) ď‚— Nerve root replantation ď‚— Free muscle and tendon transfer
- 58. Concepts of upper arm type BPI reconstruction ď‚— The nerve begins to regenerate, around 1-1.5 mm daily. ď‚— The motor endplates with which the nerve communicates will eventually cease to function in 12-18 months. ď‚— If a proximal plexus injury occurs, then the regenerated nerve may not reach the motor endplate in time to be effective. ď‚— 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 ď‚— Direct ventral intraspinal implantation ď‚— Sutureless repair ď‚— Stem cells ď‚— Synthetic Nerve grafts