Brachial plexus lesions

Esther Vögelin and Team

SGH Course 11.01.18

Handchirurgie und Chirurgie der peripheren Nerven,

Universitätsspital Bern

C5

C7

C6

C8

TH1

Surgical anatomy of the brachial plexus

• „5-3-6-3-5“

• 3 Trunks: upper, middle, lower

• 5 Roots: C5,C6,C7,C8,TH1

• 6 Divisions: 2 upper, 2 middle, 2 lower

• 3 Cords: lateral, posterior, medial

• 5 Nerves (musculocutaneus

axillary, radial, median, ulnar)

Surgical anatomy

C5

C7

C6

C8

TH1

Supraclavicular

3 Trunks

•upper trunk

(C5, C6)

•middle

trunk (C7)

• lower trunk

(C8, TH1)

Supraclavicular

5 Roots

Surgical anatomy

Retroclavicular

•6 Divisions

Upper (C5, C6)

Middle (C7)

Lower (C8, TH1)

Surgical anatomy

Infraclavicular

•3 Cords Lateral (C5, C6, C7)

Posterior (C5, C6, C7 C8, TH1)

Medial (C8, TH1)

Surgical anatomy

Infraclavicular

•5 Nerves

Musculocutaenous nerve (C5, C6,)

Axillary nerve (C5, C6,)

Radial nerve (C5, C6, C7,C8,TH1)

Median nerve (C5, C6, C7,C8,TH1)

Ulnar nerve (C7,C8,TH1)

Nerves and their muscles Plexus Nerves (n) Muscles (m)

Roots C3-C5 Phrenic diaphragma

Roots C5-C7

Root C5 Long thoracic n

Dorsal scapular n Serratus anterior m

Levator scapulae m, Rhomboids

Upper trunc C5,C6

Suprascapular n Supra-/infraspinatus m

Lateral cord C5,C6,C7

Lateral pectoral n Clavicular portion of pectoral m

Posterior cord C5,C6,C7,C8,TH1

Subscapular n

Thoracodorsal n Teres major m

Latissimus dorsi m

Medial cord C7,C8,TH1

Medial pectoral n Medial brachial and antebrachial cutan. n

Sternal portion of pectoral m Pectoral minor m

C5/C6 C5/C6 C5/C6/C7/C8/TH1

C5/C6/C7/C8/TH1 C7/C8/TH1

Musculocutaneous n Axillary n Radial n

Median n Ulnar n

Coracobrachial, Biceps, Brachial m Deltoid, Teres minor m Triceps, Brachioradial m, Extensors

Pronators, radial wrist-,finger-, thumb flexors Intrinsic hand m, ulnar wrist-,finger flexors

Examination

• Search for associated injury in high

energy trauma Closed head injury

Chest wall: proximal rib fx, hematopneumo-

thorax

Spinal cord injury

Vascular injury (6 P‘s: pain, pallor, pulselessness,

poikilothermia{cool skin}, paresthesia, paralysis)

Musculoskeletal injury (shoulder girdle fx,

dissociation, upper limb fx)

Examination

• History Severe pain in anesthetic extremity root

avulsion

Paraesthesia, weakness in other extremities

(Para-/Tetraplegia)

Improvement/changes over 3 months: yes/no

• Traction Most injuries due to stretch

Point of application, direction of force and

relationship of arm to neck determines nerves

involved

Upper/middle trunk mechanism

• Forcible widening of shoulder-neck angle

Lower trunk mechanism

• Separation of scapulohumeral angle

Pre- and postganglionic lesion

Type of pre- and postganglionic lesion

• Extensive longitudinal

injury common Combination of supra-

and infraclavicular injury

• Mixture of avulsion,

stretch and rupture Variable injury results in

uneven recovery of plexal

elements

Adult brachial plexus injury

Prof. A. Narakas, 1989

C6 root injury, upper + lower trunk

rupture, posterior cord rupture

Examination

• Establish the location of the injury Pre-ganglionic (avulsion) vs post-ganglionic

(rupture)

Post-ganglionic levels:

root/trunk/division/cord/terminal branches

• Complete vs incomplete lesion

• Sensory exam: Tinel‘s sign: location and distribution

Sensory loss: dermotomal and peripheral

nerve pattern

Sensory examination

• Tinel‘s sign: Present at site of nerve rupture

Advances with nerve regeneration

Absence in neck may imply root

avulsion

• Absence of sweating, loss of

sympathetic innervation

Motor examination

• Knowledge of pathway from roots to

individual muscles, contributions from multiple

roots important to localize pathology and plan

treatment

Examination

Pattern Involved

roots

Loss of function

Upper trunc plexus

palsy: Erb-Duchenne

C5/C6 No shoulder abduction,

external rotation, elbow

flexion

Upper and middle

trunc plexus palsy

C5/C6/C7 No shoulder function/elbow

flexion/extension + no wrist-,

finger- extension

Lower trunc plexus

palsy: Déjérine-

Klumpke

C8/TH1 No intrinsic muscle function,

ulnar wrist-, finger flexion

Total plexus paralysis C5/C6/C7/C8

/TH1 „flail arm“

Signs for preganglionic lesion

•Denervation of rhomboids, levator scapulae,

anterior serratus m (Roots C5/C6/C7)

•Horner sign (Root C8/TH1)

•No tinel sign (no conduction between spinal

cord and ganglion

•Asensitive neck (but intact sensible action

potentials)

•Hemidiaphragma paralysis (phrenic nerve)

•Pseudomeningomyeloceles: avulsion and lesion

of dura mater and arachnoid

•Fractures of transverse process

Signs for root avulsion

• Absence of Tinel‘s sign or percussion,

tenderness in supraclavicular fossa

• Parascapular muscle atrophy

• Shift of the head away from the injured side

Examination for root avulsion

• Motor branches arising from roots Dorsal scapular (C5)- rhomboids: lateral

translation and rotation of inferiar angle,

subtle

•Motor branches arising from roots

– Long thoracic (C5-C7) – serratus

anterior: winging at medial border

Examination for root avulsion

• Examination of serratus anterior function:

shoulder protraction

Examination for root avulsion

• Paralyzed diaphragm: Diaphragm C3-C5

Implies C5 avulsion

• Exam: chest percussion

(excursion)

• X-ray inspiration/exspiration

views

Examination for root avulsion: Horner‘s syndrome

• Features Ptosis

Miosis

Enophtalmus

• Implies C8/TH1 avulsion

• Caused by interruption of sympathetic

pathway

• Descends in spinal cord exiting via C8-TH2

spinal nerves

Postganglionic examination features

• Tinel‘s sign in one or more plexus dermatome

(advancing =stretch with recovery)

• Percussion tenderness supra- or infraclavicular

• Preserved movement

• Sweating in palm

• Muscle force testing BMRC (M1-M5) grade With referral to spinal level and pathway to each

muscle

Repeated (if immediate surgery deferred) to follow

recovery

Careful and complete documentation

Documentation

Initial

examination

2 years after

surgery

Conclusion of physical exam

• History and physical exam = surgeon‘s most

powerful tool Must be complete, methodical

• Life before limb injuries

• Identify possible root avulsion (phrenic nerve,

rhomboid, serratus ant palsy, horner sign, absent tinel‘s

sign)

• Systematic repeated exams: Identify common patterns of injury

Determine complete vs incomplete lesion

Follow recovery

Plan surgical reconstruction 3-6 months (postgan-

glionic, preganglionic lesions as early as possible)

Examination

• Findings in C5/C6* lesion Denervation of the following muscles: o Supra-/infraspinate muscles [no abduction (>90°),

no external rotation]

o Deltoid m [no flexion, abduction(0-90°), extension]

o Pectoralis major: no adduction against resistance

o Latissimus dorsi m: asymmetry when coughing, no

muscle palpation with both hands against the hips

• No elbow flexion/no shoulder abduction/ER

o Upper trunc (C5/C6)

o Lateral cord (C5/C6)

o Musculocutaneous nerve, axillary nerve (C5/C6)

* 15% of adult injury

Kim DH, Neurosurg focus

16(5), 2004

Examination

• Findings in C5, C6, C7 injury Absent shoulder abduction, external rotation

(no deltoid, no supra/infraspinati)

No elbow flexion

No elbow extension (triceps, Brachioradialis m) o Root C7, middle trunc,

o Posterior cord (C7)

o Radial nerve

Stretch, rupture or avulsion

Erb‘s palsy + variable triceps, wrist extensor

weakness

Examination

• Findings in C8/TH1 injury Good shoulder and elbow function

No wrist and finger flexion, no intrinsic muscle

activity

Diagnostics

• Myelo CT

• MRI

• Electrophysiologic tests (SSEP‘s)

• Intra-operative options Acetylcholintransferase activity (CAT

measurement),

SSEP‘s (somatosensory evoked potential‘s)

Direct nerve stimulation (C5)

Pattern of plexus lesions

• (all roots intact, distal lesion)

• Rupture of C5-C7, avulsion of C8,TH1

• Rupture of C5,C6, avulsion of C8,TH1

• Rupture of C5, avulsion of C6-TH1

• „Flail arm“: < 20% avulsion of all roots • Supraclavicular injuries 70%

• Infraclavicular injuries 30%

Hentz et al. In Green, Operative Hand

Surgery, 2005

Timing of surgery

• Immediate: open lesions, ischemia of major

blood vessels to the arm

• > 3-6 months after primary accident: closed

lesions depending of simultaneous injuries

• In case of documented root avulsion preferred

early reconstruction

• Surgical options:

< 12 months: - direct nerve repair (rare)

- grafting

- nerve transfer

> 12 months: - tendon transfers

- free neurotized muscle transfers,

- joint fusions

Priorities of surgery

• Elbow flexion

• Shoulder stabilization and motion Abduction and external rotation

Serratus ant/scapular stabilization

• Median nerve sensibility

• Radial motor function (Triceps, Wrist/digit

extension)

• Useful median/ulnar motor function generally

no realistic goal

Elhassan B et al. J Hand Surg

2010;35(7):1211

Yamada T et al. J Hand Surg

2010;35(9):1427

Ihara K et al. J Hand Surg

1996;21(3):381

Immediate vs early vs late surgery

• Time needed for nerve recovery (1mm/day) 50% muscle loss after 2-3 months of denervation

Loss of motor endplates @ 12-18 months

o Early: 0-6 months

o Late: 9-12 months

• Intact roots, distal lesions Intraplexular nerve transplantations

• Avulsion of roots Nerve transfer

• The more extensive the plexus lesion the more

modest the expecting reconstructive result

Priority of reconstructions

• Shoulder function Scapulohumeral (trapezius, rhomboids, serratus

anterior muscles)

Glenohumeral

ABD: (Deltoid, supraspinatus muscle): • Intraplexal nerve transfers: spinal accessory nerve

suprascapular nerve

• Trapezius muscle transfer

Rotation (IR: pectoral, subscapular muscles AR:

infraspinate muscle) • In global lesions no reconstruction

Glenohumeral arthrodesis: 15°F+Abd,45°IR

Priority of reconstructions

• Elbow flexion Biceps, brachialis m

o If C5,C6 present: intraplexal reconstructions with

nerve grafts

o if C5,C6 avulsion: • Nerve transfer: ulnar/median nerve branch

musculocutaneous nerve (double Oberlin) • Med. pectoral nerve musculocutaneous nerve

• Intercostal nerves musculocutaneous nerve

o If global avulsion: {pectoral muscles <M4);

intercostal nerves, phrenic nerve, hypoglossus

nerve, contralateral C7 (only in children) nerve transfer musculocutaneous nerve}

Oberlin et al JBJS

2004;86A:1485

Merrel et al J Hand

Surg 2001;26A:303

Chuang et al J Hand

Surg 2012;37(2):270

Nerve transfers (elbow flex)

lateral

medial

MacKinnon et al J Hand

Surg 2005;30A:978

Nerve transfers (shoulder abd)

• Spinal accessory suprascapular nerve from

posterior

Pruksakorn et al Clin anat

2007;20(2):140

SAN

SAN

SSN

SSN

Nerve transfers (shoulder abd)

• Spinal accessory suprascapular nerve from anterior

Leechavengvongs S et al.

Hand Clin 2016;32(2):153-164

Bertelli JA. J Hand Surg

2007;32A:989-998

Radial nerve Axillary

nerve

Nerve transfers (elbow ext)

• Radial nerve branche axillary nerve

Radial

nerve

Axillary

nerve

Leechavengvongs et

al J Hand Surg

2003;28A:628

Options of nerve transfers

• Early: Spinal accessory nerve (1700 axons, pure motor)

suprascapular nerve Intercostal nerves (1300 axons, 2-3 nerves ICN III-VI

best with sensory components) musculocutaneous nerve

Medial pectoral nerve radial nerve Ulnar/median nerve branches musculocutaneous

nerve Radial nerve branch axillary nerve

• Other donors: Phrenic nerve (800 axons, hemidiaphragm paralysis,

adults only), Contralateral C7 (only children), hypoglossal, cervical

plexus

Late Reconstructions

• Tendon transfers line of pull straight, one tendon = one function

Shoulder abduction/external rotation

o Upper/lower trapezius muscle transfer

Elbow flexion

o Steindler transfer

o Pectoralis major transfer

o Latissimus dorsi bipolar transfer

Grasp o If C7 or radial nerve intact: ECRLFDP;

BRFPL;EIPopponensplasty

Late: free neurotized muscle

• Innervated proximally –> power distally • Can span long distance waiting for nerve

recovery Elbow flexion Wrist extension Finger extension Finger flexion

Single or double

(elbow flex and wrist ext)

Barrie KA et al. Neurosurg

Focus.2004;16(5).E8

Late: free neurotized muscle

•Doi‘s procedure(Taiwan): •Double gracilis muscle transfer •1. Gracilis m, obturator n branch spinal accessory nerve elbow flexion + wrist extension •C5/C6 suprascapular + axillary nerves, Phrenic n suprascapular nerve

Maldonado A et al. Plast Reconstr Surg 2016;138:483-88e

Late: free neurotized muscle

•2. Gracilis muscle, intercostal nerves obturator

nerve branch

Finger flexion

• if good elbow flexion

fascia lata graft between

gracilis muscle and finger flexors

(Oberlin)

Free neurotized muscle transfer

• Power Intraplexal: AIN

Extraplexal: Spinal accessory nerve, intercostal

nerves

• Vascular supply Thoraco-acromial trunk

Late reconstructions

• Bony Arthrodesis

o Glenohumeral

o Wrist

o Thumb • CMC, IP