brachial plexus injury2019/01/23 · brachial plexus lesions - etiology closed 1. traction lesions...
TRANSCRIPT
BRACHIAL PLEXUS INJURY
By :Dr.K.Vivek
BRACHIAL PLEXUS LESIONS - ETIOLOGY
CLOSED 1. traction lesions 2. radiation induced
3. neoplastic
4. post operative
OPEN 1. gun shot wound lacerations
2. during surgeries
3. orthopedic related
4. needles and cannulas
• MC cause in large series is motor cycle accidents of 70%.
• In 20% cases a/w rupture of subclavian or axillary artery.
CLASSIFICATION OF BRACHIAL PLEXUS INJURIES:
• Upper Plexus Injuries(Erb's Palsy)• Lower Plexus Injuries(Klumpke)
• Leffert classified injuries acc to mech & level of injury
• Preganglionic or supraganglionic injuries occuring proximal to neural foramen in which neurons have been seperated from spinal cord.
• Postganglionic or infraganglionic injuries occur distal to neural foramen & neurons remain connected to spinal cord.
Indications for avulsion injuries and poor prognosis for recovery
● Finding1. Denervation of
paraspinal muscles2. Denervation of
rhombhoid muscles3. Scapular winging4. Horner’s syndrome5. Absent Tinel’s sign6. Sensory impairment
neck7. Hemidiaphragmatic
paralysis8. Cervical transverse
process fracture9. Pseudomeningocele10. Anesthesia and intact
conduction velocity
● Implication1. Dorsal ramii injury2. Dorsal scapular C5 injruy3. Long thoracic C5, C7 and C8
injuries4. Cervico thoracic sympathetic
injury5. Preganglionic seperation from
cord6. Cervical plexus injury7. Phrenic nerve injury8. Avulsion fracture with root
injury9. Dura and arachnoid avulsion
injury10. Dorsal ganglion intact but
avulsion from cord
TRUNK
• Upper trunk( Erbs palsy) c5,c6• Middle trunk c7• Lower trunk( Klumpke paralysis)C8,T1
Upper Brachial Plexus Injuries• Increase in angle between
neck & shoulder• Traction (stretching or
avulsion) of upper rootlets (e.g., C5,C6)
• Produces Erb’s PalsyLower Brachial Plexus Injuries• Excessive upward pull of
limb• Traction (stretching or
avulsion) oflowerrootlets (e.g., C8,
T1)• Produces Klumpke’s
Palsy
Lower brachial plexus injuries
Upper brachial plexus injuries
Erb’s Palsy (C5-C6)
General Comments Physical ExamMost common obstetric plexopathy
Clinically, arm will be adducted, internally rotated at shoulder, pronated, extended at elbow (“waiter’s tip position”)
Results from excessive displacement of head to opposite side & depression of shoulder on same side producing traction on plexus
C5 Deficiency-Axillary nerve def. (weakness in deltoid, teres minor)-Suprascapular nerve def. (weakness in supraspinatus, infraspinatus)-Musculocutaneous nerve def. (to biceps and brachialis)
Occurs during difficult delivery in infants or falls onto shoulder in adults
C6 Deficiency-Radial nerve def. (weakness in brachioradilis, supinator)
Best prognosis
LATERAL CORD
1.Isolated lesion to lateral cord consists of musculocutaneous nerve palsy plus a partial median nerve deficit ( involving C5 to C7 portion )This deficit pattern is termed a musculocutaneous plus palsy
2.The classic musculocutaneous palsy causes forearm flexion weakness secondary to biceps brachii, corachobrachialis and brachialis weakness and sensory loss in the lateral forearm
3.The lateral cord provides all the median nerve’s sensory fibers. So, sensory loss in the lateral palm and first 3 digits occurs with a lateral cord injury
4.Proximal median innervated muscles(pronator teres, FCR)weakness in pronation and wrist flexion.
MEDIAL CORD1.An isolated medial cord lesion consists of an ulnar nerve palsy plus loss of C8 and T1 components of the median nerve.
2.An ulnar nerve palsy would cause weakness in wrist flexion (flexor carpi ulnaris), distal interphalangeal joint flexion weakness involving the ring and little fingers (flexor digitorum profundii ), little finger movements ( opponens, flexor and abductor digiti minimi ), and finger abduction and adduction ( interossei ).
3.Medial cord sensory loss involves the medial 1/3rd of the hand
4.Medial cord lesion or ulnar plus palsy would in addition to causing ulnar motor loss, cause median innervated thumb weakness(opponens pollicis,flexor pollicis brevis,abductor,) and trouble extending the proximal interphalangeal joints of the 1st two fingers (lumbricals).
5.Medial pectoral nerve from proximal medial cord, if damaged leads to weakness in the sternal head of the pectoralis major.
POSTERIOR CORD
1.Combination palsy of radial and axillary nerve is the hallmark of posterior cord injury.Also called radial axillary palsy.
2.Radial palsy causes weakness in forearm extension (triceps), forearm supination (supinator), wrist extension ( extensor carpi radialis longus and brevis, extensor carpi ulnaris ), and finger/thumb extension ( superficial and deep finger extensors )
3.Radial nerve sensory loss involves the posterior arm and forearm, the lower lateral aspect of arm and lateral dorsal hand.
4.An axillary nerve palsy causes arm abduction weakness secondary to deltoid paralysis.
5.An axillary nerve lesion can also cause sensory loss in the upper lateral arm
Plain RadiographsPlain X ray film Findings Significance
Chest Elevated hemidiaphragm Phrenic injury, proximal plexus, and possible preganglionic avulsion
First rib fracture Subclavian or axillary artery injury – Lower trunk injury
C – spine Fracture or dislocation Cervical spine injury
Transverse process # Preganglionic avulsion injury
Clavicle Fracture Possible traction injury to plexus or pseudoparalysis
Shoulder Glenohumeral dislocation Infraclavicular injury
Scapulothoracic dislocation Severe neurovascular injury
Imaging study
1.C T Myelography or MRI may show pseudomeningoceles produced by root avulsion(6 to 12 weeks recommended ).
2.Note that during the first few days a ‘positive’ result is unreliable because the dura can be torn without there being root avulsion.
3.MRI shoes pseudo meningocele or complete absence of root shadows at the level of avulsion (inaccurate early after injury bcoz clotted blood may occlude pseudo meningocele)
4.MRI for pt with traction injury to the brachial plexus
TINEL SIGN
1.Percussion by finger Transient tingling sensation Distal to proximal direction
2.Indicate regenerating axonal sprouts that have not obtained complete myelinization are progressing along the neural tube
Elicited by placing a drop of histamine on the skin along the distribution of the nerve being examined
Skin scratched through the drop of histamine : cutaneous vasodilation, wheal formation, and flare response
Nerve interrupted proximal to the ganglion:anesthesia along its cutaneous course, normalaxon response Injury is distal to the ganglion : anesthesia along
the course of the nerve, and vasodilation and wheal formation seen, flare response absent
Sweat test
Sympathetic fibres within a peripheral nerve are resistant to mechanical trauma
Autonomous zone – presence of sweating –no complete interruption of nerve Iodine starch test- quinizarin powder
Denervated area—dry and light gray
Normal area – purple colour
Studies-Nerve action potential (NAPs)
• Often intraoperative• Tests a nerve across a lesion• If NAP positive across a lesion
– preserved axons– or significant regeneration
• Can detect reinnervation months before EMG– NAP negative-neuropraxic lesion– NAP positive- axonotmetic lesion
NERVE CONDUCTION STUDY-electrical stimulate-it should be done after 10 days
-Nerve conduction studies need careful interpretation. If there is sensory conduction(sensory nerve action potentials) from an anaesthetic dermatome.
- This suggests a preganglionic lesion
-This test becomes reliable only after a few weeks, when wallerian degeneration in a postganglionic lesion will block nerve conduction
ELECTROMYOGRAPHYAfter 10 to 14 days of neural injury,abnormal spontaneous rest potentials evolve(positive sharp waves)b/w 14 to 18 days fibrillation appear.Abnormal spontaneous rest potentials may last indefinitely until the muscle has become reinnervated or fibrotic3 months of injury peripheral neural sprouting occur and the motor unit potential amplitute progressively increasesb/w 2 to 6 months larger than normal appearing potential .
SKIN RESISTANCE TEST
-Richter dermometer -Denervated area– increased resistance to electrical currentInnervated area – normal resistance-Galvanic stimulation: chronaxy and strength duration curve
MANAGEMENT
• Closed Brachial Plexus Injury• Open Brachial Plexus Injury
Closed Brachial Plexus Injury• Barnes divided Upper & Lower
Plexuses injuries caused by traction into four groups
• 1)Injuries at C5 & C6(spontaneous recovery)
• 2)Injuries at C5,C6 & C7• 3)Degenerative lesions of entire
plexus(partial recovery)• 4)Injuries at C7,C8 & T1 (rare)
Open Brachial Plexus Injury
• Indications for Surgery:• Injuries caused by sharp objects
or missiles.• Injuries to adjacent vessels or
mediastinal, thoracic viscera must be treated first
• When pt not seen soon after injury but only after initial management,
• It is best to wait for wound healing & stabilization of any other injuries.
• During this period locate neurological deficit for level of injury.
• EMG performed 3 to 4 wks after injury.
• Exploration of plexus & neurorrhaphy, autogenous interfascicular nerve grafting or neurolysis is indicated 3 to 6wks after injury.
SURGICAL GOALS
In order of priority as follows:
-Restoration of elbow flexion
- Restoration of shoulder abduction
-Restoration of sensation of medial
borderof forearm & hand(neurovascular island
graft).
Important Nerves for Upper Brachial
Plexus Injury & ReconstructionNerve Muscles
innervatedFunction
Musculocutaneous Biceps & Brachialis Elbow flexionAxillary Deltoid Shoulder abductionSuprascapular Supraspinatus Shoulder abduction
and stabilityMedian Wrist & Finger
Flexion, Radial Hand Sensation
Wrist & Finger Flexion, Hand Sensation
Ulnar Wrist & Finger Flexion, Ulnar Hand Sensation
Wrist & Finger Flexion, Ulnar Hand Sensation
Neurolysis Nerve repair NeurorraphyNerve GraftNerve TransferFunctional muscle transfer
•
- Effective only if scar tissue seen around nerve or inside epineurium, preventing recovery or causing pain
-External neurolysis
-Internal neurolysis
NEURORRHAPHY
-Epineural
-Perineural
-Interfascicular
METHODS OF CLOSING GAP
-Mobilization-Positioning of extremity-Transposition-Bone resection-Nerve grafting-Nerve allograft-Synthetic nerve conduits
Surgical Techniques-Nervegraft
• Commonly used due to traction injuries (postganglionic).
• Preferable to graft lesions of upper and middle trunk
• Donor sites include sural nerve, medial brachial nerve, medial antebrachial cutaneous nerve
Nerve repairs performed with fibrin sealants produced less inflammatory response and fibrosis, better axonal regeneration, and better fiber alignment than the nerve repairs performed with microsutures alone.
Act as a temporary scaffold across which axons regenerate
Ultimately, the allograft tissue completely replaced with host material
Tacrolimus, greater potential and fewer side effects than other
immunosuppressants, neuroregenerative and neuroprotective effects
Help in directing axonal sprouts from the proximal stump to the distal nerve stump
Provide a channel for diffusion of neurotropic and neurotrophic factors and minimize infiltration of fibrous tissue
Silicone,polygalactin,poly L lactic acid,poly glycolic acid,polyvinyl alcohol
Surgical Techniques-Neurotization
(Nerve Transfers)• Transfer working but less important motor nerve to a nonfunctioning more important denervated muscle
• Use extraplexal source of axons– spinal accessory nerve (CN XI)– intercostal nerves– contralateral C7– hypoglossal nerve (CN XII)
• Intraplexal nerves– phrenic nerve– portion of median or ulnar nerves– pectoral nerve– Oberlin transfer
• ulnar nerve used for upper trunk injury for biceps function
Nerve Transfer Options (Upper Plexus
Injured Nerve
Nerve Transfer Function Restored
Musculocutaneous
Median and Ulnar (FCU)fascicles/ICN
Elbow flexion
Axillary Radial fascicles Shoulder Stability & abduction
Suprascapular Spinal accessory (XI) fascicles
Shoulder Stability & abduction
After brachial plexus repair & regeneration 12 to 18 mths required to determine extent
of neural regeneration.
If recovery inadequate Peripheral
reconstruction considered
tendon transfer about the elbowBUNNEL AND CAROLL PROCEDURE
Anterior transfer of the triceps tendon
FLEXORPLASTY(steindler)Indications: -biceps and brachialis paralysed -detach the common flexor group muscles ---advance 5 cm lateral side rather than medial side of humerus
TRANSFER OF PECTORALIS MAJOR TENDON
BROOK AND SEDDON To restore the elbow flexion in which pectrolis major muscle is used as motor and its tendon is prolonged distally by means of long head of biceps.
• To improve shoulder ABDUCTIONand EXTERNAL ROTATION• Tendon transfer around shoulder
considered include TRAPEZIUS TO DELTOID transfer
• For abduction LATISMUS DORSI & TERES MAJOR transfer as described
by L'Episcopo FOR ER of shoulder jt.
BATEMAN PROCEDURE Trapezius insertion freed by resecting the lateral clavicle, acromion,adjoining part of scapular spine are anchored to the humerus by screws
SHOULDER ARTHRODESIS
●If active scapulothoracic motion is preserved
●To improve elbow flexion by preventing uncontrolled IR of shoulder
●Shoulder fused in 20 to 30 degrees of abduction