2018 HTRC Irvine Brachial Plexus Barrett - ASHT · Dermatomes vs. Cutaneous Innervation Axillary C5...

Hand Therapy Review CourseUC Irvine

February 9, 2018

Brachial Plexus & Nerve Innervation of the Upper Extremity

Nora Barrett, MS, OTR/L, CHT

Objectives

Brief review of normal and compromised neuroanatomy

Brachial plexus anatomy

Spinal nerves: pathways, classic lesions, and compression sites




NeuroanatomyCentral Nervous System Inside brain and spinal cord

Peripheral Nervous SystemOutside brain and spinal cord

CNS & PNS work together as continuum from cortex to motor and sensory end organs

PNS injury—> affects cortical level Large cortical representation of

hand Neural change in hand—> change

in cortex

Peripheral Nerve Anatomy: Connective Tissue

Epineurium-binds fascicles into named nerve

Perineurium-surrounds fascicles

Endoneurium-surrounds the axon

Connective tissue Protection vs.

compression, traction

Allows lengthening

Provides nutrition

Connective Tissue In vulnerable areas of the

body such as anatomic tunnels there are usually more fascicles in the nerves

Fascicle arrangement more complex proximally Jabaley: protection from compression, tensile forces

More fascicles means more epineurium to protect axons from friction or pressure Sunderland: 21-81% CT, >% closer to joint

Connective Tissue

Greater fasiculi: greater connective tissue protection:less deformation with mechanical stress

Connective Tissue Undulations of the nerves allow for more

nerve gliding without tension “Spiral bands of Fontana” Dellon & MacKinnon: absent in area of compression

Normal muscle tone helps prevent excessive traction to the nerve

Nerve TractionUndulation Stretched

Progressive Disruption• Axon• Endoneurium• Perineurium• Epineurium

The elastic limit of a nerve is thought to be about 20%

Nerve Injury

Agents of nerve injury are mechanical, thermal, chemical, or ischemic

Motor loss results in venous/lymphatic stasis; muscle atrophy; muscle/joint fibrosis

Sensory loss results in decreased functional use and increased risk for burn/pressure injury

Sympathetic loss results in vasomotor, sudomotor, pilomotor, and trophic changes

Sympathetic Effects

Vasomotor--changes in skin temperature, color, edema, and cold intolerance

Sudomotor -- changes in sweat patterns (hypohidrosis in denervated areas; hyperhidrosis with partial nerve injury)

Pilomotor -- absence of “goose flesh” Trophic--changes in skin texture; atrophy of finger

pulps; nail changes; hair growth changes (hyper/hypotrichosis); slowed skin healing

VASOMOTOR CHANGES POST NERVE INJURY

FUNCTION EARLY CHANGES LATE CHANGES

SKIN COLOR ROSY MOTTLED/CYANOTIC

SKIN TEMPERATURE

WARM COOL

SUDOMOTOR CHANGES POST NERVE INJURY

FUNCTION EARLY CHANGES LATE CHANGES

SWEAT DRY SKIN DRY OR OVERLY MOIST

PILOMOTOR CHANGES POST NERVE INJURY

FUNCTION EARLY LATE

GOOSEFLESH RESPONSE

ABSENT ABSENT

TROPHIC CHANGES POST NERVE INJURY

FUNCTION EARLY LATE

FINGERNAILS BLEMISHES CURVED IN LONGITUDINAL AND HORIZONTAL PLANES

HAIR GROWTH LONGER, FINER AND MAY FALL OUT

LONGER, FINER AND MAY FALL OUT

RATE OF HEALING SLOW SLOW

SKIN TEXTURE SOFT/ SMOOTH SMOOTH/ NONELASTIC

SOFT TISSUE ATROPHY SLIGHT MORE PRONOUNCED(ESP AT FINGER PULPS)

SOURCE: Callahan, Anne D. : SensibilityTesting: Clinical Methods Rehab of the Hand , ed2, 1984 The CV Mosby Co.




Anatomy of the Plexus

• Roots C5 through T1

• Begins distal to the scalenes

• Prefixed and Postfixed

Anatomy of the Plexus

• Roots

• Trunks

• Divisions

• Cords

• Nerves

Anatomy

Brachial Plexus: Roots

Location: Behind anterior scalene muscle

Direct BranchesDorsal scapular nerve C5

○ Rhomboid muscles○ Levator scapulae muscle

Long thoracic nerve C5,6,7○ Serratus anterior muscle

Dermatome / Myotome

Specific skin areas supplied by a specific spinal nerve, regardless of the cutaneous nerve that supplies that area (relates to sensation)

Typically crosses 2 or more joints

Represent motor function (weakness)

C5- muscles above elbow except triceps

C6- elbow region C7- muscles in mid

forearm C8, T1- muscles of

hand

Upper Extremity Myotomes

C4 resisted shoulder shrugs (UT)

C5 resisted shoulder abduction (Delt)

C6 resisted elbow flexion (Biceps)

C7 resisted wrist flexion (FCR, Triceps)

C8 resisted thumb extension (EPL, FDS)

T1 finger abduction & adduction (Interossei)

Dermatomes vs. Cutaneous Innervation

Segmental Testing C5Motor: DeltoidReflex: BicepsSensation: Lateral Arm

Segmental Testing C6Motor: Biceps, wrist extensorsReflex: BrachioradialisSensory: Thumb/IF

Segmental Testing C7Motor: Triceps, Wrist Flexors, Finger Ext Reflex: TricepsSensation: Middle finger

Segmental Testing C8

Motor: finger flexors

Reflex: none

Sensation: ring and small fingers

Segmental Testing T1

Motor: Interossei

Reflex: None

Sensation: Medial proximal forearm

Brachial Plexus: Trunks Location: between lateral

border of anterior scalene and clavicle

Upper Trunk C5,6Middle Trunk C7 Lower Trunk C8,T1

Direct branches:Subclavian nerve C5,6

○ Subclavius m.Suprascapular nerve

C5,6○ Supraspinatus muscle○ Infraspinatus muscle

Trunk Lesion Symptoms-segmental Upper trunk lesion: proximal pain,

paresthesias in C5,6 dermatome Lower trunk lesion: distal pain, paresthesias

medial arm, hand

SS

Deltoid

IS

Where is this lesion occurring?

Hint:Wasting of Supraspinatus, InfraspinatusWhich nerve innervates SS, IS?Where does it come off BP?

Also wasting of Deltoid (and TM)Which nerve innervates Delt & TMinor?Where does this nerve come off the BP?

TMinor

Thoracic Outlet Supraclavicular region

containing the brachial plexus and the subclavian artery/vein

Syndrome often correlated with faulty posture, adaptive shortening of anterior cervical and chest muscles, prolonged overhead arm use, and pec minor hypertrophy

Brachial Plexus: Divisions Location: behind clavicle

Cause of lesion: clavicle fracture

Anterior: innervate volar structures

Posterior: innervate dorsal structures

Direct branches: Lateral anterior thoracic

nerve C5,6,7 Pectoralis major (clavicular

head)

Brachial Plexus: Cords

Location Below clavicle, behind

pectoralis minor

Motor and sensory deficits follow the distribution of the affected peripheral nerve

Named relative to axillary artery

LATERAL POSTERIOR MEDIAL

Lateral Cord Medial

Posterior




Nerves exiting from Lateral Cord

Musculocutaneous nerve C5,6,7Biceps

Brachialis (along with radial nerve)

Corocobrachialis

Lateral root of Median nerve C5,6,7Motor to all median nerve muscles except the

intrinsics

Lateral CordThe Lateral Cord gives rise to two nerves

Lateral portion of Median Nerve:PT, FCR, PL, FDS(weak)

Musculocutaneous Nerve:CoracobrachialisBicepsBrachialis

Musculocutaneous nerveLateral Cord

Musculocutaneous pierces coracobrachialis

Lateral Cord

Musculocutaneous nerve C5,6

Arises from lateral cord

Innervates biceps, brachialis(with radial) and corocobrachialis

Sensory branches to lateral forearm: lateral antebrachial cutaneous nerve

Functional deficit Biceps atrophy Weak elbow flexion in

supination Decreased sensation along

radial and volar aspects of forearm

Lateral CordDermatomes vs. Cutaneous Innervation

Musculocutaneous

C5C6

Posterior CordUpper subscapular nerve C5,6

Subscapularis muscle

Lower subscapular nerve C5,6 Teres major muscle

Axillary nerve C5,6○ Deltoid muscle

Thoracodorsal nerve C6,7,8 Latissimus dorsi muscle

Radial nerve C5,6,7,8,T1Triceps, BR, Anconeus, ECRL/B, Supinator,

ECU, EDC, EDM, APL, EPL, EPB, EIP

Posterior Cord

Posterior Cord The Posterior Cord gives rise to 5 nerves

Axillary Nerve: Deltoid Teres minor

Upper/Lower Subscapular Nerve: SubscapularisTeres Major

Thoracodorsal Nerve: Latissimus Dorsi

Radial Nerve:Triceps, BR, Anconeus, ECRL/B,Supinator, ECU, EDC, EDM, APL, EPL, EPB, EIP

Axillary nerve

Posterior CordAxillary Nerve C5,6

Arises from posterior cord

Originates ventral aspect of subscapularis

Passes laterally toward inferior shoulder joint just inferior to humeral head

Through quadrangular spaceMedial border: humerusLateral border: long head of tricepsSuperior border: teres minor Inferior border: teres major

Wraps horizontally around post surgical neck of humerus

Enters deltoid

Posterior Cord

Axillary Nerve C5,6 Innervates deltoid and teres minor. A

sensory branch supplies the lateral aspect of the upper arm/deltoid tuberosity area

Functional loss-shoulder Abd/ER/elevation, numbness of lateral upper arm

Possible causes of lesions:Shoulder dislocationHumeral neck fractureSerum/vaccine inducedBrachial neuritis

Posterior Cord


Axillary

C5C6

Axillary Nerve Injury

Posterior Cord

Deltoid and teres minor wasting

Deltoid

Deltoid

TM

Radial Nerve

Posterior Cord

Radial Nerve C6,7,8,T1

Arises from posterior cord

Emerges between long and medial heads of triceps

Crosses under lateral head of triceps, pierces lateral intermuscular septum, enters anterior compartment of arm

Diverges anterior to radial head in forearm

Posterior Cord

Radial Nerve C6,7,8,T1 Cutaneous branches:Posterior cutaneous of

arm

Lower lateral cutaneous of arm

Posterior cutaneous of forearm

Motor innervation:Triceps

Anconeus

BR

ECRL

Brachialis (musculocutaneous)

Posterior Cord

Radial Nerve in Forearm Bifurcates at anterior radial

head Superficial branch/DRSNDescends forearm just

medial to BRCutaneous supply to

dorsoradial hand Deep branch/PIN SupinatorECRBEDCEDMECUEPL, EPB, APLEIPTerminates in dorsal wrist

capsule: proprioception

Posterior Cord


Radial

C6C7C8T1

Superficial RADIAL NERVE Sensory Innervation lesion to the radial sensory nerve

Posterior Cord

Radial Nerve Palsy

RADIAL NERVEPotential Sites of Compression

Radial Groove of Humerus

Lateral Intermuscular Septum

Fibrous Band between BR and Brachialis/ECRB

Leash of Henry

Arcade of Frohse

Supinator

Distal BR

Medial Cord

Medial ant. thoracic nerve C8,T1Pectoralis minor musclePectoralis major muscle

Medial cutaneous nerve of arm C8,T1Medial cutaneous nerve of forearm C8,T1Ulnar nerve C8,T1Medial root of median nerve C8,T1

Median intrinsics and cutaneous in the hand

Medial CordThe Medial Cordgives rise to threemotor nerves

Medial Ant. Thoracic N.: Pectoralis Major/ Minor

Ulnar Nerve:FCU, FDP ¾, AddP, FPB,Lumbrical ¾Interossei, ADM,ODM,FDM

Medial Portion of the Median N.: FDS, FDP 1,2, FPL, PQ, APB, FPB, OP, Lumbricals 1,2

Median Nerve

Lateral root of median nerve from lateral cord

Medial root of median nerve from medial cord

Medial and Lateral Cords Median Nerve C5,6,7,8,T1 Arises from medial and

lateral cords

Descends arm in medial neurovascular bundle with ulnar nerve and brachial artery

Moves laterally to enter cubital fossa and passes deep to bicipital aponeurosis

Exits cubital fossa between 2 heads of PT and fibrous FDS arch in forearm

Medial and Lateral Cords

Median nerve in the forearm Median Nerve C5,6,7,8,T1 AIN branches off median

nerve at approximately level of PT or FDS arch

Median nerve continues in deep position down forearm between FDS and FDP

Medial Palmar Cutaneous (superficial palmar nerve)branches from median at distal 1/3 of FA

Median curves laterally at proximal wrist to be volar to FDS to cross into hand under TCL


AIN

Median Nerve C5,6,7,8,T1 Median motor innervation:PTFCRPLFDSFPB (superficial head)APBOPLumbricals 1 + 2

AIN motor innervation:FPLPQFDP to IF (MF)Terminates in volar wrist

capsule: proprioceptive input

Medial and Lateral Cords Median NerveLevel of the Carpal Tunnel


Median Nerve

Cutaneous branch supplies skin of lateral thumb, 2 1/2 digits volarly and distal to the PIP joints dorsally

Median Palmar Cutaneous (superficial palmar nerve) supplies skin of lateral hand and base of thenar eminence


MEDIAN NERVE Sensory Innervation

AREA OF SENSORY CHANGE DUE TO COMPRESSION AT THE CARPAL TUNNEL

Medial Cord

AREA OF SENSORY CHANGE DUE TO COMPRESSION PROXIMAL TO THE CARPAL TUNNEL


Median

C5C6C7C8

Median Nerve

Causes of injury: Lacerations of the arm, forearm, wrist, or hand

Prolonged compression

Ulnar dislocation

Fracture of elbow joint or distal radius

Toxic or infectious neuritis


MEDIAN NERVE Potential Sites of Compression Ligament of Struthers- RARE (1%)

Lacertus Fibrosis/Bicipital Aponeurosis

Pronator Teres

Flexor Digitorum Superficialis

Transverse Carpal Ligament

Ulnar Nerve Medial Cord Ulnar Nerve C8,T1 Arises from medial cord

Descends arm in medial neurovascular bundle with median nerve, brachial artery

At distal 1/3 of arm, passes through medial intermuscular septum into posterior compartment

Descends supracondylar area in fascial groove, crosses elbow posteriorly in condylar groove

Enters FA passing between medial epicondyle and olecranon then deep to FCU

Medial Cord

Ulnar Nerve C8,T1 Passes through entire FA deep

to FCU

DUCN, UPC branch off ulnar nerve about distal third of FA

At FCU attachment to pisiform, ulnar nerve passes lateral to pisiform and medial to hook of hamate

Ulnar nerve branches superficial (cutaneous) and deep (motor) within this canal (Guyon’s)

Medial CordUlnar Nerve C8,T1

Motor innervation in FA: FCU FDP to RF/SF

Motor innervation in hand:ADMFDMODMPalmar and Dorsal InterosseiLumbricals 3 & 4Deep head of FPBADd Pollicis

Medial Cord

Ulnar Nerve C8,T1

Cutaneous branch supplies skin of ulnar 1 1/2 digits volarly and distal to the PIP joints dorsally

Ulnar Palmar Cutaneous supplies skin of ulnar volar palm

Dorsal Ulnar Cutaneous supplies the skin of the dorsomedial hand

Medial Cord ULNAR NERVE Sensory Innervation

AREA OF SENSORY CHANGE FROM LESION OF THE ULNAR NERVE DISTAL TO THE DORSAL CUTANEOUS BRANCH

AREA OF SENSORY CHANGE FROM LESION OF THE ULNAR NERVE DISTAL TO PALMAR CUTANEOUS BRANCH

Medial Cord


Ulnar

C8T1

Ulnar NervePotential Sites of Compression

Arcade of Struthers

Medial Intermuscular Septum

Subluxing Medial Head of Triceps

Cubital Tunnel

Flexor Carpi Ulnaris

Guyon’s Canal

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Ulnar Nerve Compression Sites

Cubital Tunnel Guyon’s Canal

Review of Objectives




THANK YOU!

Acknowledgements:Lorna Canavan Kahn, PT, CHT Milliken Hand Rehabilitation CenterSt. Louis, Missouri

Keith Segalman, MDCurtis National Hand CenterBaltimore, MD

ReferencesBell Krotoski JA. Sensibility Testing: History, Instrumentation, and Clinical

Procedures in Rehabilitation of the Hand and Upper Extremity, 6th Edition. Skirven, Osterman, Fedorczyk, Amadio. Elsevier/Mosby: Philadelphia, PA 2011.

Boyd KU, Nimigan AS & MacKinnon SE. Nerve Reconstruction in the Hand and Upper Extremity. Clin Plast Surg. 2011 Oct; 38(4):643-60.

Callahan A. Sensibility Assessment For Nerve Lesions-In-Continuity and Nerve Lacerations in Rehabilitation of the Hand and Upper Extremity, 5th Edition. Hunter, Mackin, Callahan. Mosby: St. Louis, MO 2002.

Fox IK & MacKinnon SE. Adult Peripheral Nerve Disorders- Nerve Entrapment, Repair, Transfer and Brachial Plexus Disorders. Plast Reconstr Surg 2011 May; 127(5).

Giuffre JL, Kakar S, Bishop AT, Spinner RJ & Shin AY. Current Concepts of the Treatment of Adult Brachial Plexus Injuries. JHS 2010; 35A:678-688.

Henry FP, Farkhad RI, O’Shaughnessy M & O’Sullivan ST. A Comparison Between Complete Immobilisation an Protected Active Mobilization in Sensory Nerve Recovery Following Isolated Digital Nerve Injury. J Hand Surg Eur 2012 Jun; 37(5):422-6.

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References (cont)Hooper TL, Denton J, McGalliard MK, Brismee JM & Sizer PS. Thoracic

Outlet Syndrome: a controversial clinical condition. Part I: anatomy, and clinical examination/diagnosis. J Manual & Manipulative Therapy 2010 Jun; 18(2):74-83.

Kattan AE & Borschel GH. Anatomy of the Brachial Plexus. J Ped Rehab Med: An Interdisciplinary Approach 2011; 4:107-111.

Limthongthang R, Bachoura A, Songcharoen P & Osterman AL. Adult Brachial Plexus Injury Evaluation and Management. Orthop Clin N Am 2013; 44:591-603.

Novak CB & Mackinnon SE. Outcomes Following Conservative Management of Thoracic Outlet Syndrome. JHS 1995; 20(4):542-548.

Osterman AL & Lincoski C. Thoracic Outlet Syndrome in Rehabilitation of the Hand and Upper Extremity, 6th Edition. Skirven, Osterman, Fedorczyk, Amadio. Elsevier/Mosby: Philadelphia, PA 2011.

Pratt N. Anatomy of Nerve Entrapment Sites in the Upper Quarter. J Hand Ther 2005; 18:216-229.

Sheth RN & Campbell JN. Surgical Treatment of Thoracic Outlet Syndrome: A Randomized Trial Comparing Two Operations. J Neurosurg Spine 2005; 3(5):355-363.

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Duchenne Sign

Claw deformity of thering and small finger

Low ulnar nerve palsy

*RF/SF MCP hyperextension due to unchecked pull of extrinsic extensors and absence/weakness of intrinsic extension (lumbricals and interossei) *IP joints in flexion due to unopposed extrinsic flexors*FDP weakness with high ulnar nerve palsy diminishes this posture

Andre Thomas Sign

Exaggeration of the claw deformity: In attempt to straighten fingers, wrist falls into flexion during action of the extensors (tenodesis) to the middle finger

Crossed Finger Sign

*Weakness of the interossei limiting ability of the middle finger to fully cross the index finger*Compare with uninvolved side

Egawa Sign

*MF unable to ab/adduct when flexed at IP joints (hook fist position) *IP joint flexion limits ability of extrinsic extensors to give appearance of ab/adduction

Froment Sign

*Patient asked to pull/resist piece of paper held between thumb and radial index finger (lateral type grasp)*With loss/weakness of Adductor Pollicis, Flexor Digitorum Profundus overcompensates with thumb IP joint flexion

Jeanne Sign *Thumb MCP hyperextension in addition to IP joint flexion*Observed during evaluation of Adductor Pollicis (paper pull/resist test or resisted lateral pinch)

Wartenberg Sign

*Small finger posturing in abduction*Inability/weakness limiting SF adduction to RF

Masse Sign*Intrinsic muscle wasting causing flattening of the hypothenar eminence and metacarpal arch

2018 HTRC Irvine Brachial Plexus Barrett - ASHT · Dermatomes vs. Cutaneous Innervation Axillary C5...

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