Comprehensive Guide to Brachial Plexus: Anatomy, Injuries & Nerve Blocks

1. Upper Limb:Nerves ClinicalAnatomy

2. Brachial Plexus • Ventral rami ofC5‐T1 • Formed in the posterior triangle of theneck • Organization • Roots • C5‐T1 • Trunks • UpperC5‐C6 • MiddleC7 • LowerC8‐T1 • Divisions • Anterior and posteriordivisions • Cords • Lateral • Anterior divisions of middle & upper trunks • Medial • Anterior division of lowertrunk • Posterior • All the posteriordivisions

3. BrachialPlexus: Relations • Scalenus anterior and medius • Axillaryartery • Axillarysheath

4. Brachial Plexus:Branches • Roots • Dorsal scapularn. • Long thoracicn. • Uppertrunk • Suprascapularn. • Nerve to subclavius • Lateralcord • Lateral pectoraln. • Musculocutaneousn. • Lateral root of mediann. • Posteriorcord • Upper subscapularn. • Thoracodorsaln. • Lower supscapularn. • Axillary n. & radialn. • Medialcord • Medial pectoral n. • Medial cutaneous n. ofarm • Medial cotaneous n. of forearm • Ulnarn. • Medial root of mediann.

6. Upper lesions of the brachial plexus (ErboDuchenne Palsy) • Increase the angle between the head andshoulder • Injury to C5 & C6roots • Affectedmm. • Supraspinatus, infraspinatus, subclavius, biceps brachii, coracobrachialis, deltoid, and teres minor • Waiter’s tipposition • Limb hang byside • Medially rotated • Pronatedforearm • Loss of sensationdown lateralside

7. Lower lesions of the brachial plexus (KlumpkePalsy) • Injury to C8 &T1 • Excessive abduction of thearm • Affectedmm. • Small handmuscles • Claw hand • Hyperextension of metacarpophalangealjoints • Flexion of interphalangealjoints • Loss of sensation down medialside

8. Long thoracic nerve injury • Resultsfrom • Injury to posterior triangle of the neck • Injury in the chestwall • Radicalmastictomy • Paralysis of serratus anteriorm. • Winged scapula • Difficult to raise hand abovehead • Medial border and inferiorangle moves laterally andposteriorly

9. MusculocutaneousNerve • Relations • Pierces coracobrachialism. • Deep tobiceps • Branches • Muscularnn. • Innervate the anterior compartment of armmm. • Lateral cutaneous nerve of theforearm

10. Musculocutaneous NerveBlock • Area: lateral side of the forearm(cutaneous) • Lateral cutaneous n. block • Lateral to the tendonof the bicepsm. • On a line betweenthe humeralepicondyles

11. MedianNerve • Relations • Inarm • Brachiala. • Inhand • Flexorretinaculum

12. Median Nerve:branches • Branches inforearm • Muscularbranches • Anterior compartment of forearm • Palmar cutaneousbranch • Branches in palm • Muscularbranches • Thenarmuscles • Cutaneous branches

13. Median nerveinjury • Injury at theelbow • Forearm kept in supineposition • Wrist flexion is weak and accompanied byadduction • No flexion at interphalangeal joints of 2nd and 3rd fingers and weak flexion at the metacarpophalangeal joints of thesefingers • Sensory loss at lateral half of the palm

14. Median nerveinjury • Injury at wrist • Paralysis and atrophy of the thenarmm. • Loss of oppositionmovement • Carpal tunnelsyndrome • Compression of the median n. by the content of the carpal tunnel • Pain (pins and needles) along the distribution of the median n. to the lateral 3 & ½ fingers

15. Median NerveBlock • Area: lateral side of the palm and palmer 3½ digits and their nail beds • Block atelbow • Brachial a. palpated to the medial side of the biceps tendon on an extendedelbow • Medial to the palpated brachiala. • Block atwrist • Between tendons of the palmaris longus and flexor carpi radialismm. • Proximal to the flexor retinaculum (proximal to distal transverse crease ofwrist)

16. UlnarNerve • Relations • Inarm • Medialepicondyle • Inhand • Flexorretinaculum • Pisiform

17. Ulnar Nerve:branches • Inforearm • Muscularbranches • Cutaneousbranches • Posterior cutaneousbranch • Palmar cutaneousbranch • Inhand • Superficial terminalbranch • Muscular branches (palmaris previs m.) • Cutaneousbranches • Deep terminalbranch • Muscularbranches

18. Ulnar nerveinjury • Injury atelbow • Common site for ulnar injury is posterior to the medialepicondyle • Flexion of wrist will accompanied by abduction • Inability to adduct and abduct the fingers • Clawdeformity • Loss of sensation on the medial ⅓ of the hand • Injury atwrist • Claw hand • Loss of sensation on ⅓ of palmarside

20. Ulnar NerveBlock • Block atelbow • Area: medial side of thehand • – Between olecranon process and medial epicondyle ofhumerus • Block at wrist • Area: palmer side of the medial side of thehand • – Lateral to the tendon of the flexor carpi ulnaris m. at level of transverse crease ofwrist

21. RadialNerve • Relations • inarm • Spiralgroove • Profunda a. • Lateralepicondyle

22. Radial Nerve:branches • Muscularbranches • Posterior compartments ofarm and forearm • Cutaneous branch • Posterior cutaneous n. ofarm • Lower lateral cutaneous n. ofarm • Posterior cutaneous n. offorearm • Superficial branchof radialn.

23. Radial nerveinjury • Injury in theaxilla • Wrist‐drop • Injury in the spiralgroove • Wrist‐drop • Injury to the deepbranch • No wrist‐drop • Inability to extend the thumb and the metacarpophalangeal joints (test against resistance) • No loss ofsensation • Injury to the superficial branch • Limitedanasthesia

24. Radial NerveBlock • Area: lateral dorsal side of the hand proximal to the lateral 1½ lateral nailbeds • Block atelbow • Halfway between the tendon of the biceps m. and the tip of the lateral epicondyle of humerusin extendedelbow • Block atwrist • Lateral to the radial a.at the level of the proximal wrist transversecrease

25. AxillaryNerve • Relations • Quadrangularspace • Posterior circumflex humeral vessels • Branches • Anterior terminalbranch • Posteriorterminal branch • Upper lateralcutaneous • n. of the arm

26. Axillary NerveInjury • Results from injury inthe quadrangular space • Downward humeral dislocation • Humeral fracture at surgical neck • Deltoid m.paralysis • Deltoid atrophy • Loss of sensation over the lower half of deltoidmuscle

27. Cutaneous Innervation of the UpperLimb Musculoskeletal Axillary Radial Ulnar Median Medialcord

28. Dermatomes of the UpperLimb

29. Dermatomes & Cutaneous Nerves of theHand

30. Dermatome Tests for the UpperLimb

31. Tendon Reflexes & Segmental Innervation of the Upper LimbMuscles • Biceps brachii tendonreflex • – C5&C6 • Flexion of the elbowjoint • Tapping on the bicepstendon • Triceps tendonreflex • – C6‐C8 • Extension of the elbowjoint • Tapping on the tricepstendon • Brachioradialistendon reflex • – C5‐C7 • Supination of the radioulnar joint • Tapping the brachioradialis tendon

32. The specific neurovascular manifestations of acute cervical discherniation

33. Myotome Tests for the UpperLimb • Abduction of Arm(C5) • Supraspinatus –Supraspinatus Nerve • Deltoid‐AxillaryNerve • Arm Adduction(C7) • Pectoralis Major‐ Pectoral Nerves • Latissimus Dorsi‐ ThoracodorsalNerve • Forearm Flexion (C5‐6) • Brachialis‐Musculocutaneous • Biceps Brachii‐ Musculocutaneous

34. Myotome Tests for the UpperLimb • Forearm Extension(C7) • Triceps Brachii‐Radialnerve • Wrist Flexion (C7,8T1) • Flexor CarpiRadialis‐ MedianNerve • Flexor Carpi Ulnaris‐Ulnar Nerve • Wrist Extension(C7,8) • Extensor Carpi Radialis (Longus andBrevis)‐Radial Nerve • Extensor CarpiUlnaris‐ Posterior Interosseous Nerve

35. Myotome Tests for the UpperLimb • Finger Flexion(C7,8T1) • Flexor Digitorum Superficialis‐ MedianNerve • Flexor Digitorum Profudus‐Ulnar & Anterior Interosseous branch ofMedian • Finger Extension(C7) • Extensor Digitorum‐Posterior Interosseous branch ofRadial • Thumb Abduction (C7,8T1) • Abductor Pollicis Longus‐Radial Nerve • Abductor Pollicis Brevis‐Median Nerve

36. Myotome Tests for the UpperLimb • Thumb Opposition (T1) • Opponens Pollicis:Median Nerve • Finger Abduction(C8,T1) • Dorsal Interossei & Abductor Digiti Minimi‐UlnarNerve • Finger Adduction(C8,T1) • Palmarinterossei‐Ulnar Nerve • http://www.youtube.com/w atch?v=rKiTwagLYck