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BRACHIAL PLEXUS INJURIESChairperson : Dr D. kale

Presenter : Dr Saumya Agarwal

Dept of Orthopaedics, JNMC,KLES Dr.Prabhakar Kore Hospital, Belagavi

ANATOMYThe brachial plexus is an arrangement of nerve fibres, running from the spine, formed by ventral rami of lower cervical and upper thoracic nerve roots

includes from above the fifth cervical vertebra to underneath the first thoracic vertebra(C5-T1).

It proceeds through neck, axilla and into the arm. It is responsible for cutaneous and muscular innervation of entire upper limb.

RELATIONSIn the neck, it lies in posterior triangle, being covered by skin, Platysma, and deep fascia where it is crossed by supraclavicular nerves, inferior belly of Omohyoid, external jugular vein and transverse cervical artery.

When It emerges between Scaleni anterior and medius; its upper part lies above third part of subclavian artery, while trunk formed by union of eighth cervical and first thoracic is placed behind artery.

Next it pass behind the clavicle, Subclavius, and transverse scapular vesselsand lies upon first digitation of Serratus anterior and Subscapularis.

In axilla it is placed lateral to first portion of axillary arteryit surrounds the second part of artery one cord lying medial to it, one lateral to it and one behind it at lower part of the axilla it gives off its terminal branches to the upper limb.

Parts of Brachial PlexusR = ROOTS (ventral rami)T = TRUNKSD = DIVISIONSC = CORDSB = BRANCHES

Roots join to form Trunks! (in neck) Ventral Rami Trunks

C5Upper TrunkC6C7 Middle TrunkC8T1 Lower Trunk

Trunks Split to form Divisions! (in neck) Trunks Divisions

UpperAnteriorPosterior

MiddleAnteriorPosterior

LowerAnterior Posterior

Divisions Join to form Cords! (in axilla)U A PM A P

L A P POSTERIOR CORD

LATERAL CORD

MEDIAL CORDTrunksDivisionsCords

LandmarksInterscalene triangle- roots , trunks

Lateral Border of first rib-divisions

Medial Border of the coracoid process- cords

BRANCHES FROM ROOTS

DORSAL SCAPULAR NERVE

Root value- C5Supply Rhomboid major & minor muscle

Posterior view

LONG THORACIC NERVE

Root value- C5,C6,C7Supply Serratus anterior muscle

BRANCHES OF UPPER TRUNK NERVE TO SUBCLAVIUS Root value C5,C6

SUPRASCAPULAR NERVERoot value C5,C6

BRANCHES FROM CORDSLateral cord Musculocutaneous nerve(C5,C6) Lateral pectoral nerve (C5,C6) Lateral root of median nerve (C5,C6)

Medial cord Medial cutaneous nerve of arm (C8,T1) Medial cutaneous nerve of forearm(C8,T1) Medial root of median nerve(C8,T1) Medial pectoral nerve (C8,T1) Ulnar nerve(C7,C8,T1)

Posterior cord Upper subscapular nerve(C5,C6) Lower subscapular nerve(C5,C6) Nerve to latissimus dorsi (C6,C7,C8) Axillary nerve(C5,C6) Radial nerve(C5,C6,C8,T1)

LATERAL PECTORAL NERVE Root value- C5,C6,C7MEDIAL PECTORAL NERVE

Root value- C8,T1

MUSCULOCUTANEOUS NERVE

Root value C5,C6,C7

12-18MEDIAN NERVE

MEDIAL CUTANEOUS NERVE OF ARMRoot value- C8,T1

MEDIAL CUTANEOUS NERVE OF FOREARMRoot value- C8,T1

12-20 ULNAR NERVE

Root value-(C7),C8,T1

UPPER SUBSCAPULARRoot value-C5,C6

LOWER SUBSCAPULARRoot value- C5,C6

NERVE TO LATISSIMUS DORSIRoot value-C6,C7,C8

AXILLARY NERVE

RADIAL NERVE

DERMATOMES OF UPPER LIMB

Neurological Examination

APPLIED ANATOMY

TENDON REFLEXESBiceps brachii tendon reflexe (C5,C6)

Triceps tendon reflex (C6,C7,C8)

Brachioradialis tendon reflex(C5,C6,C7)

Brachial plexus lesions

CLOSEDa)Traction lesions-Avulsion-Obstetric palsy

b)Radiation induced

c)Neoplastic-Primary-Secondary

d)Post operative-post medial sternotomy

OPEN-gun shot wounds-lacerations-during surgeries-needles and cannulas

EPIDEMIOLOGYBrachial plexus injuries afflict slightly more than 1% of multitrauma victims.

Motorcycle accidents carry especially high risks, with the incidence of injury approaching 5%.

Injury ClassificationMillesi classification*

SupraganglionicInfraganglionicTrunkCord

Anatomical Classification

C5-6 waiters tip (Erbs palsy)C5-7 as above, elbow slightly flexedC5-T1 flail limb, claw hand, vasomotor changes, +/- Horners syndrome

Preganglionic InjuryNerve root avulsiondorsal & ventral rootletsinvested by pia mater / dural funnel

etiology: traction (occasionally missile, knife)Significant traction causes dural rupture / root vulnerabilityventral > dorsal root (esp C8-T1) at higher riskPOOR Prognosis!

Mechanism of injury

Traction or stretch -most common cause -mostly affects supraclavicular portion of brachial plexus

Contusion or Bruising: -It leaves the nerves in gross continuity But causes severe intraneural damage -Gunshot wounds are the common cause

Compression:Crutches ,backpack straps, clavicle fracture callus, tumors, hemorrhage .

Ischemia:Neurovascular injuries compromise in microcirculation- Post irradiation progressive fibrosis, hyalinization and obliteration of brachial plexus

Degree of nerve injuryClassified according to Seddons andSunderlands classification

Seddons classification

Seddons and Sunderlands Classification

Related Special Tests Brachial PlexusCervical Compression Test

Cervical Distraction Test

Spurlings Test

Brachial Plexus Traction TestThoracic Outlet SyndromeAdsons Test

Allens Test

provider turns the patient's head to the affected side while applying downward pressure to the top of the patient's head

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Peripheral Nerve TestsAxillary N.Sensory Lateral armMotor Shoulder abduction

Musculocutaneous N.Sensory Anterior armMotor Elbow flexion

Radial N.Sensory 1st Dorsal web spaceMotor Wrist extension and thumb extensionMedian N.Sensory Pad of Index fingerMotor Thumb pinch and abductionUlnar N.Sensory Pad of little fingerMotor Finger abduction

ERBS PARALYSIS

Erb point

Causes

Nerve roots involved

Muscles Paralysed

Deformity

LEFT SIDE PARALYSIS

Klumpkes paralysis-

Named after augusta djerine-klumpke

Site of injury

Cause of injury

Nerve roots involved

Muscles paralysed

Deformity

CLAW HANDHORNER SYNDROME

MUSCULOCUTANEOUS NERVECauseMuscle paralysedDisability SUPRASCAPULAR NERVECauseMuscle paralysedDisability

AXILLARY NERVE

Causescrutch pressing upward into the armpit, Downward shoulder dislocationsfractures of the surgical neck of the humerus. Motor effects:

Sensory effects:

Deformity:

MEDIAN NERVE

Cause-

Site of injury-

Muscles paralysed-

DeformityRIGHT SIDE

ULNAR NERVE

Causes-

Axilla- crutch pressureArm- # of shaft of humerusElbow- # of medial epicondyleForearm- penetrating injuriesWrist- cut and stab wounds

Muscles paralysed-

Deformity

ULNAR PARADOXulnar nerve innervates the ulnar (medial) half of theflexor digitorum profundus muscle(FDP). If lesion occurs more proximally (closer to the elbow), the flexor digitorum profundus muscle may also be denervated. As a result, flexion of IP joints is weakened, which reduces the claw-like appearance of the hand.(Instead, the fourth and fifth fingers are simply paralyzed in their fully extended position.) This is called the "ulnar paradox" because one would normally expect a more proximal and thus debilitating injury to result in a more deformed appearance.

RADIAL NERVECause-

Site of injury-

Muscles paralysed-

Deformity

Brachial Plexopathies:TraumaticMajority are closed traction injuries at high velocity (MVA)

More often affects supraclavicular plexus - forced separation of head and shoulder

Infraclavicular injury forced separation of arm from torso Root avulsions are the most serious complication Ventral roots more susceptible because of lesser caliber, thinner dural sacs

open traction or penetrating injuries are less common

Damage by direct contact or delayed manner (hematoma, pseudoaneurysm)

Penetrating injury more commonly affect infraclavicular plexus

Take Home Messages:

Most closed injuries are lesions in continuity and should initially be treated conservatively

Focal lesions that show no sign of recovery after 2-3 months warrant surgical consideration

Sharp lacerations should be repaired early (within 72 hours)

Additional indications for acute intervention: - worsening neurologic dysfunction - worsening pain - compartment syndrome - bone or vascular injury

Obstetric Brachial PlexopathyShoulder dystocia impedes vertex delivery, resulting in excessive lateral deviation of the head22% bilateral involvement May follow Cesarian-section Risk factors: - macrosomia - short mothers - forceps delivery - vacuum extraction - prolonged second stage labor - multiparity - passive head rotation

5 Patterns of nerve involvement:

1. C5-6 (Erbs palsy, 50%)2. C5-7 (Erbs-plus palsy, 35%, classic waiters tip position; axillary, musculocutaneous, suprascapular)3. C5-T1 with some finger flexion sparing4. C5-T1 with flail arm and Horners5. C8-T1 and Horners (Klumpkes, rare)

Generally recommend observation period (3-9 months). Spontaneous recovery 75-90%

Burner SyndromeForceful separation of the shoulder and head- if associated with pain and paresthesias, the term stinger or burner is applied

- males, contact sports- classically C6 distribution

- permanent neurologic dysfunction is rare

- prolonged symptoms warrant further investigation

Rucksack palsy (cadet palsy, pack palsy)Classic: painless weakness associated with wearing a backpack

Risk factors: pack weight, worn for a long duration

Most are demyelinating conduction block

Conservative treatment

Postoperative Paralysis:Presents in immediate postoperative setting

Usually Unilateral upper plexopathy

Painless weakness

Typically demyelinating conduction block

Conservative treatment

Brachial PlexopathiesSupraclavicular Plexopathies

True neurogenic thoracic outlet syndrome:Affected C8 and T1 fibers are stretched by a band that connects a cervical rib to the 1st rib

More common in womenTrue incidence 1 per million

T1 affected more than C8, electrodiagnostics should support this fact

True neurogenic thoracic outlet syndrome:

Surgical lysis of fibrous band or rib resection

Postmedian sternotomy plexopathy: Clinical and electrodiagnosticstudies implicate C8 Theory: compression of C8 fromfracture of 1st rib or rotation of 1strib Conservative Treatment

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Pancoast syndrome:Only pleura separates lung from T1 3% of lung cancer patients (may be 1st manifestation of NSCC)Shoulder pain, worse at night Radicular component along medial aspect of arm, may involve C8 distribution Associated with Horners syndrome

Radiation-induced:Brachial PlexopathiesInfraclavicular Plexopathies

Typically females ( axillary lymph node radiation for breast cancer) Painless paresthesias precede weakness

Relentless progressive (demyelinating-> axon loss) Differentiate from neoplastic recurrence: - radiation: isolated paresthesias predominate - neoplastic: higher incidence of pain, Horners

Neuralgic Amyotrophy (Parsonage-Turner):

Frequently involves long thoracic, axillary, and suprascapular nerves Presenting feature: abrupt shoulder pain, often nocturnal onset

Pain abates after 7-10 days Weakness

Spontaneous Recovery 89% by 3 years

BRACHIAL PLEXUS BLOCK-Techniques-Interscalene Brachial Plexus Block

Supraclavicular(Subclavian)Brachial Plexus Block

Infraclavicular Brachial Plexus Block

Axillary Brachial Plexus Block

Anesthetic implications

DIAGNOSIS Relies mainly on clinical examinationCT myelographyMRINerve conduction studies

InvestigationsSensory nerve action potentials (SNAPs): differentiate preganglionic from postganglionic injuries.

Electromyography (EMG): In the first week after injury, EMG cannot be used to exclude a complete disruption unless voluntary motor unit action potentials are observed. If no signs of denervation are present in a paralyzed muscle by 3 weeks after injury, EMG can be used to confirm a neuropraxia.

Somatosensory evoked potentials (SSEPs): In general, SNAPs are more reliable than SSEPs. Many difficulties exist with SSEPs, and they are not widely used.

NCS is a test commonly used to evaluate function of motor and sensory nerves of human body.

Nerve conduction studies are used mainly for evaluation of paresthesias (numbness, tingling, burning) and/or weakness of arms and legs.

Indications :Symptoms indicative of nerve damage as numbness, weakness.Differentiation between local or diffuse disease process (mononeuropathy or polyneuropathy).Get prognostic information on the type and extent of nerve injury.Nerve Conduction Study (NCS)

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Common disorders diagnosed

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Description of the Procedure

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Description of the procedure (continued..)

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Components of NCSThe NCS consists of the following components:Compound Motor Action Potential (CMAP); also called Motor nerve conduction studySensory Nerve Action Potential (SNAP); also called Sensory nerve conduction studyF-wave studyH-reflex studyA-(Axon) wave studyBlink Reflex studyDirect Facial Nerve Study

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Motor nerve conduction study corresponds to integrity of motor unit but cannot distinguish between pre- and postganglionic lesions because cell body is located in the spinal cord.

Compound Motor Action Potential

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Motor nerve conduction study sites

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Sensory nerve conduction studyrepresents conduction of an impulse along the sensory nerve fibers

performed by electrical stimulation of a peripheral nerve and recording from a purely sensory portion of nerve, such as on a finger

recording electrode is placed proximal to stimulating electrode.

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Sensory nerve conduction study sites

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F-wave studyevokes a small late response from a short duration supramaximal stimulation.

H- reflex study creates a late response that is an electrically evoked analogue to a monosynaptic reflex. initiated with a submaximal stimulus at a long duration

Interpretation of nerve conductions speed of nerve conduction is related to diameter of nerve and,degree of myelination (a myelin sheath is a type of "insulation" around the nerve)

A normally functioning nerve will transmit a stronger and faster signal than a damaged nerve

range of normal conduction velocity will be approximately 50 to 60 meters per second

may vary from one individual to another and from one nerve to another

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Electro Myo Graphy

Pattern of EMG Recorded Findings Resting activity Muscle relaxed & needle not moving No activity Insertion activity Needle is moved to sampling spots within insertion tract Brief AP Motor unit potential Needle is not moved while patient makes slight contraction few motor . unit AP, biphasic or . triphasic RecruitmentSubject makes progressively stronger muscle contraction until reaching maximum force Increase . number of . movement until . baseline is obscured

TREATMENT Most injuries recover without any RxRx is done in very highly specialized centers

Surgical optionsnerve transfersnerve graftmuscle transfersneurolysis of scar around brachial plexus in incomplete lesion

Advances in nerve injury Rx

Carlstedt obtained promising initial results with the repair of preganglionic lesions by replanting nerve rootlets directly into the spinal cord.

This is a dramatic advance because preganglionic lesions were previously thought to be irreparable

ManagementSurgical options: Immediate vs delayed (timing contraversial)Indications for Surgery at time of injury Open injuryHigh energy injurySupraclavicular injuryAssociated depressed clavicle fracture:explore and immediate repair / nerve grafts

Surgery 3 months post injury IF CLOSED (and no sign recovery): nerve grafts (if not done ); nerve transfer if supraganglionic

Surgery >1 year post injury: local or free muscle transfer starting at proximal joint

Planning for ReconstructionWhat is the loss?What is the need?What is possible?What is available?What are the other injuries?Is later surgery needed and what can be done now?

What is the loss?Shoulder motionShoulder stabilityElbow flexionWrist and hand functionSensationPainTrophic changesBody image

What is available?Primary repair: Very rareNeurolysis only with late surgeryPlexus anatomical cable graftingNerve transfersAccessory nerveCervical plexusPhrenic nerveIntercostal nervesUlnar ECU nerveCrossed C7Hypoglossal nerveNerve graftsSuralmedial cutaneous forearmulnar (vascularised)

Closed injury, (tractional injuries)

Early explorationUnderobservationDecision for the time of delay explorationDecision for the type of the treatment

Late recostruction

Straight on Brachial plexus

Peripheral reconstruction

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Early exploration

Underobservation

First 6-12 weeksStabilization of the patientStabilization of the injuryEvaluation of the improvement

After 2-3 monthsNo improvement; explorationProgressive improve; wait & watchNon-anatomic recovery; explor.Based on severityvascular reconstruction

Decision for the time of delay explorationNo recoveryAfter 6-12 weeks (based on the severity of the trauma)Progressive improvementWait for further improvement Non-anatomic recoveryExploration before 9-12 months

Treatment options availableNeurolysisNerve repairNerve graftNerve transfer

Tendon transferArthrodesis

Functional muscle flaps

Straight on Brachial Plexus

Early explorationDelay exploration

Peripheral reconstruction

Late reconstruction Danger of more damage Failure is obvious

G Gun shot injury

After neurolysis from scar tissue

Nerve graft

Self transfer (i.e. Sural Nerve)Manufactured NerveProcessed NerveCadaver TransplantLiving Related Transplant

Nerve transfer..Neurotization

Accessory nerveCervical plexusPhrenic nerveIntercostal nervesUlnar ECU nerveCrossed C7Hypoglossal nerve

Motor cycle accident open wound

C5C6Vertebral foramen

Accessory Injured upper trunkSuperascapular nerve

Oberlin nerve transferBiceps m.Ulnar n.Anastamosis

Triceps to Biceps

Latismus dorsi transferto flexion elbow and extension finger

Arthrodesis

Shoulder arthrodesis in BPI

Functional Muscle Flaps

Gracillis harvestAccessory n.

SummaryBrachial plexus injury

Open sharp injuryShot gun Tractional injury

Immediate explorationunder observation

Exploration No improvement in 2-3 mExplor. In 12 m. Non-anatomic improvement

Peripheral reanimation > 12m .

Gradual improvementLow energyHigh energy

QUESTIONS FOR EXAM ?Long question :Brachial plexus injuries and management?

Short question :Ulnar paradoxAnterior nerve transpositionRadial nerve injuries and managementMedian nerve injuries and management