1 nerves of upper extremity

nerves of upper extremity

1. NERVES OF UPPER EXTREMITY MAJ DR POONAM SINGH DEPT OF ANATOMY NAIHS

2. OBJECTIVES ORIGIN, ROOT VALUE, COURSE, BRANCHES AND APPLIED OF MAJOR NERVES OF UPPER EXTREMITY

3. BRACHIAL PLEXUS- imp nerves

4. BRACHIAL PLEXUS: NERVES DISTRIBUTION OF MAIN NERVES AXILLARY – Deltoid & Teres minor MUSCULOCUTANEOUS – Muscles of Anterior Compartment of arm (flexors) MEDIAN – Most of the Flexor muscles of forearm & Intrinsic muscles in hand- labourer ULNAR – FCU & part of FDP (forearm) and Intrinsic muscles in hand- musician RADIAL – Innervates all Extensor muscles of arm & forearm

5. MUSCULOCUTANEOUS NERVE

6. MUSCULOCUTANEOUS NERVE Arise opposite lower border of Pectoralis Minor. Derived from C5-C7 cervical ventral rami Course : Supplies Coracobrachialis and then pierces it. Descends laterally between Biceps and Brachialis to lateral side of arm. Just below elbow it pierces deep fascia. Continues as lateral cutaneous nerve of forearm..

7. Supplies – Coracobrachialis, Biceps and most of Brachialis. Branch to Brachialis supplies Elbow joint. Br to humerus via nutrient art

8. LESIONS OF MUSCULOCUTANEOUS NERVE Commonest causes Isolated lesion is rare. injuries to upper arm and shoulder including fracture of humerus.

9. LESIONS OF MUSCULOCUTANEOUS NERVE Symptom and sign Marked weakness of elbow flexion because of paralysis of biceps brachii and much of brachialis Sensory impairment on the extensor aspect of the forearm in the distribution of lateral cutaneous nerve of the forearm.

10. AXILLARY NERVE

11. AXILLARY (CIRCUMFLEX) NERVE From posterior cord (C5 - C6) . Posterior to Axillary artery (3rd part) and anterior to Subscapularis , Above posterior circumflex humeral vessels, traverses quadrangular space. Axillary trunk supplies a branch to shoulder joint.

12. BRACHIAL PLEXUS- POST CORD Axillary N cont’d Divides into anterior and posterior branches. Anterior branch along posterior circumflex humeral vessels, curves behind the humeral neck, Supplies Deltoid (deep to). skin over its middle part.( cutaneous branches which pierce the muscle )

13. Posterior branch Anterior br of Axillary Nerve

14. Posterior branch supplies Teres minor Branch to Teres minor has a pseudoganglion posterior and lower part of Deltoid. upper part of long head of Triceps upper lateral cutaneous nerve of arm

15. Commonest causes Dislocations of shoulder Fractures of upper end humerus Misplaced injections into deltoid Symptom and sign Wasting and weakness of Deltoid - abduction of shoulder affected. sensory loss on outer aspect of upper arm below acromion . LESIONS OF AXILLARY NERVE

16. MEDIAN NERVE

17. 17 MEDIAN NERVE Formed by two roots: Medial & Lateral roots Contribution from both cords Medial Root - derived from Medial cord, C8 & T1 Crosses downward and laterally infront of 3rd part of Axillary and join Lateral root) Lateral root – continuation of lateral cord, C5 to C7 Supplies flexors of forearm Labourer’s Nerve Thickest nerve of Brachial Plexus FORMATION

18. Formed in Axilla lateral to 3 rd part of Axillary artery 18 MEDIAN NERVE: COURSE

19. 19 In arm- Nerve descends lateral to Brachial artery In middle of arm crosses in front of artery runs on its medial side to Cubital fossa

20. 20 At elbow- lies deep to Bicipital aponeurosis in front of Brachialis Medial to Brachial art

21. 21 MEDIAN NERVE: COURSE Forearm Enters forearm Bt two heads of Pronator Teres Then passes deep to tendinous bridge (formed by humero-ulnar & radial heads of FDS) Descends bt FDS & FDP in forearm 5 cm above Flexor retinaculum emerges from behind lateral edge of FDS

22. 22 passes deep to tendinous bridge of FDS formed by humero-ulnar & radial heads of FDS

23. 23 Descends between FDS & FDP in forearm

24. 24 5 cm above Flexor retinaculum emerges from behind lateral edge of FDS

25. 25 MEDIAN NERVE: COURSE wrist becomes superficial bt FDS & FCR tendons) Passes deep to flexor retinaculum to enter palm

26. 26 BRANCHES IN ARM Vascular brs  ( symp twigs ) to brachial artery Branch to pronator teres  above elbow IN FOREARM Muscular brs a). Trunk of median nv  Flexors of forearm except FCU & medial half of FDP b). Ant Interrosseous nv  arise from median nv as it passess between 2 heads of PT - Runs infront of Interrosseous membrane - supplies Deep flexors:- Lat ½ of FDP, FPL & PQ - Supplies joints Distal Radio- Ulnar joint Radio- Carpal joint Carpal joints

27. 27 MEDIAN NERVE: BRANCHES Forearm cont’d 2. ARTICULAR - Elbow joint - Proximal R- U joint PALMAR CUTANEOUS Given proximal to flexor retinaculum Passes over retinaculum. Supplies central palm, Skin thenar eminence, 4. COMMUNICATING Frequently present. To ulnar nerve .

28. 28 MEDIAN NERVE: BRANCHES IN HAND Recurrent branch recurrent branch – supplies Thenar muscles Lateral branch / Main Nerve Lateral branch divides into 3 proper palmar digital branches. Supply : skin of thumb Lat side of index finger. Supplies msls : 1st lumbrical.

29. 29 MEDIAN NERVE: BRANCHES Medial branch Divides into two common palmer digital nerves. These further divide into Proper palmer digital nerves Supply : Sides of index, middle & half of ring fingers. 2nd lumbrical summary All proper palmar digital nerves reach on dorsum of Hand to supply nail beds and palmar aspect of lateral 3 ½ fingers Lateral two l umbricals supplied by Median

30. 30 MEDIAN NERVE: BRANCHES

31. 31 MEDIAN NERVE: CUTANEOUS INNERVATION PALM

32. 32 MEDIAN NERVE: CUTANEOUS INNERVATION DORSUM OF HAND- short of nailbeds

33. 33 MEDIAN NERVE - APPLIED Median Nerve Injury At Elbow Carpal Tunnel Syndrome Pronator Syndrome

34. 34 MEDIAN NERVE INJURY AT ELBOW All muscles paralyzed except FCU & FDP (medial half) MOTOR LOSS FDS & FDP ( LAT. HALF) – Loss of flexion at MP & IP Jts ( OCHSNER’S CLASPING TEST – When patient asked to clasp the hands, index finger of affected side fails to flex – remains as Pointing Index Finger ) FCR - Loss of flexion of wrist Ulnar deviation on attempts of flexion of wrist. FPL - Inability to flex terminal phalanx of thumb. PQ and PT – pronation lost 5. Thenar eminence : muscles of thenar region affected – Flattening of eminence. Ape like hand Abductor Pollicis Brevis and Opponens Pollicis– Paralysis. ( PEN TEST : Hand laid flat on table. Patient asked to touch a pen kept at slightly higher level than palm with the thumb)

35. 35 MEDIAN NERVE INJURY AT ELBOW INJURY RESULTS IN Loss of pronation : PT & PQ Loss of powerful flexion at wrist : FCR & FDS (wrist deviates to ulnar side) Loss of flexion of PIP of all digits : FDS is paralyzed Loss of flexion of DIP & MCP Joints of index and middle fingers FDP – lat. ½ & Lumbricals 1st , 2nd paralyzed) Loss of flexion, abduction & opposition of thumb : Thenar muscles paralyzed Thumb in adducted & extended position : APE LIKE HAND

36. 36 CARPAL TUNNEL SYNDROME Most common entrapment mononeuropathy Incidence - females over 50 years. 50% cases B/L. Mostly in dominant hand. Cause - Compression of Median nerve in fibro- osseous tunnel beneath flexor retinaculum. Tunnel may be narrowed by a) Arthritic changes in wrist joint (RA) b) Anterior dislocation of Lunate / complication of Colle’s fracture c) Soft tissue thickening in Myxoedema & Acromegaly d) Oedema, Obesity, Pregnancy

37. 37 CARPAL TUNNEL SYNDROME Symptoms impairment of finer movements (sewing, knitting, picking a pin) paresthesia - attacks of pain, tingling & numbness of radial 3 ½ digits of affected hand. wakes patient at night.

38. 38 CARPAL TUNNEL SYNDROME cont’d On examination Wasting Of Thenar Eminence – Muscle affected: AbPB & OP Hypo aesthesia – palmar aspect of radial 3 ½ digits. skin over thenar eminence and palm not affected as it is supplied by palmar cutaneous br of median N which arise proximal to carpal tunnel. Tinel’s Sign – Percussion of Median nerve gently at wrist causing tingling sensation radiating into hand. Tinel’s

39. 39 CARPAL TUNNEL SYNDROME cont’d Wrist Flexion Test ( Phalen’s Sign ) – Exacerbation of symptoms when patient is asked to flex wrist. Symptoms disappear as wrist straightened. surgical treatment – Carpal tunnel release. Partial or complete division of flexor retinaculum

40. 40 Thenar atrophy

41. 41 PRONATOR SYNDROME . Uncommon entrapment neuropathy of Median Nerve Anatomical basis Deep to Biceps aponeurosis Between two heads of Pronator Teres Through a fibrous arch of Flexor Digitorum Superficialis Clinical Features: Pain & tenderness in proximal aspect of anterior forearm. Weakness of all muscles innervated by Median nerve. Including Abductor Pollicis Brevis & long finger flexors. Sensory impairment on palm of hand.

42. ULNAR NERVE

43. ULNAR NERVE FORMATION Branch of Medial cord. - One of the terminal branch. Supplies small muscles in hand that are involved in fine intricate hand movements Called MUSICIAN’S Nerve. ROOT VALUE :- (C7) C8-T1 C7- contribution from median N (lat cord) 43

44. ULNAR NERVE : COURSE Axilla Forms in Axilla . Runs on medial side of axillary artery 44

45. ULNAR NERVE : COURSE arm runs medial to Brachial Artery till middle. Pierces IM septum & enters posterior compartment. Descends in front of medial head of Triceps along superior ulnar collateral artery (br of Brachial Art) 45

46. Ulnar nerve medial to artery Enters posterior compt by piercing medial IM septum 46

47. Ulnar nerve lies infront of medial head of triceps and then behind the medial epicondyle 47

48. ULNAR NERVE : COURSE elbow lies in a groove on dorsal aspect of medial epicondyle interval bt medial epicondyle and olecranon process. 48

49. ULNAR NERVE : COURSE forearm Enters forearm bt humeral & ulnar heads of FCU (Cubital Tunnel ) Runs downwards in medial side of forearm. 49

50. COURSE Rest on FDP and under cover of FCU. Ulnar artery is radial to nerve. Gives palmar cutaneous ( hypothenar eminence) and dorsal branch Enters palm by passing over flexor retinaculum 50 Ulnar N rest on FDP undercover of FCU which has been removed here

51. ULNAR NERVE : COURSE wrist enter palm by passing over flexor retinaculum . Ulnar N lies lateral to pisiform and medial to hook of hamate . Ulnar art is lateral to Nerve 51

52. COURSE Both are bridged over by a slender band of fibrous tissue (superficial part of retinaculum )  volar carpal lig forming a canal – GUYON’S CANAL. Palm In palm it passes deep to Palmaris brevis and divides into superficial & deep branches. 52

53. 53

54. In palm it passes deep to Palmaris brevis Right palm 54

55. Ulnar N lies lateral to pisiform and medial to hook of hamate. Right palm 55

56. Right palm 56

57. ULNAR NERVE : COURSE IN PALM Superficial branch – supplies Palmaris Brevis & skin on medial 1 1/2 side of hand. Divides into 2 palmar digital nerves can be compressed against hook of hamate 1st palmar digital branch – medial side of little finger 2nd palmar digital branch – adjacent sides of little & ring fingers 57

58. 58

59. ULNAR NERVE : COURSE IN PALM Deep branch – Passes bt Abductor & Flexor digiti minimi and then bt Opponens Digiti Minimi & 5TH Metacarpal. Follows course of deep palmar arch deep to flexor tendons . 59

60. Supplies : Hypothenars , Interossei – dorsal and palmar Lumbricals 3rd & 4th Adductor Pollicis ( at times Flex Poll Brevis) Ends by supplying Adductor Pollicis – Grave yard 60

61. Ulnar N Deep branch entering bt abductor digiti minimi and flexor digiti minimi 61

62. Passes bt Abductor & Flexor digiti minimi and then bt Opponens Digiti Minimi & 5TH Metacarpal. Right palm 62

63. ULNAR NERVE : Branches ARTICULAR Elbow joint Wrist joint Small joints of hand- intercarpal and carpometacarpal joints CUTANEOUS Palmar cutaneous branch : Skin of hypothenar eminence Dorsal branch : Dorsal 1 ½ digits (medial) on dorsum of hand MUSCULAR AT FOREARM FCU FDP (med. Half) 63

64. TERMINAL Superficial branch : Supplies Palmaris Brevis & medial 1 ½ digits Deep branch : (muscular) Supplies Hypothenars : Ab Digiti Minimi, Flex Digiti Minimi, Opponens Digiti Minimi Interossei : All 4 Dorsal & 4 Palmar Lumbricals : 3rd & 4th (medial two) Thenar : Adductor Pollicis & Flex. Poll. Brevis (sometimes) VASCULAR Vascular twigs to Axillary, Brachial, Ulnar and Deep palmar arch. 64

65. MUSCLES SUPPLIED IN FOREARM These muscles are primarily flexors of the wrist and fingers FCU FDP (Med.half ) 65

66. MUSCLES SUPPLIED IN FOREARM FCU FDP (Med. half) 66

67. MUSCLES SUPPLIED IN HAND Palmar aspect Dorsal aspect 67

68. ULNAR NERVE: CUTANEOUS INNERVATION OF HAND SUPERFICIAL BRANCH OF RADIAL PALM DORSUM MEDIAN ULNAR ULNAR 68

69. LESIONS OF ULNAR NERVE 1. AT THE WRIST Ulnar nerve may be compressed in Guyon's canal or deeply thro msl of hypothenar eminence trough formed by pisiform medially and hook of hamate laterally Tight pisohamate lig 69

70. Preservation of FDP to ring and little fingers. Dorsal cutaneous branch and palmar branch of Ulnar nerve are spared – lesion is distal to their origin from main trunk of Ulnar nerve in forearm Lesion of Superficial (to digits) and deep branches ( intrin msls ) Presentation Ulnar claw hand (medial two fingers are extended at MCP jt and flexed at the IP jt. Hypo aesthesia medial 1 ½ fingers 70

71. LESIONS OF ULNAR NERVE 2. AT THE ELBOW Ulnar nerve lesion due to : vulnerable position – lies between medial epicondyle & olecranon: lies on bone covered only by a thin layer of skin. Easily damaged if ulnar groove is shallow. Cubital tunnel syn Entrapment neuropathy bt two heads of FCU 71

72. LESIONS OF ULNAR NERVE Presentation Weakness of FDP affect ring & little fingers. Produce ulnar claw hand with straighter fingers Called “ ulnar paradox ” – lower lesion has more claw feature All intrinsic msls of hand and sensations lost Radial deviation of wrist on flexion 72

73. LESIONS OF ULNAR NERVE HAND Deep motor branch of Ulnar nerve compressed against pisiform & hamate - When hand is used as a mallet, or if a vibrating tool or motorcycle handlebar is held in such a way that Hypothenar eminence is off the edge of the handle. Sensory branches are always spared. involvement of hypothenar muscles is variable. (depends on the level at which branches to these muscles arise) 73

74. Ulnar claw hand with lesion at wrist FDP spared 74

75. Ulnar claw hand FDP affected – lesion higher level 75

76. True claw hand – due to lesion of ulnar and median N 76

77. RADIAL NERVE

78. 78 RADIAL NERVE Nerve of Extensors of - arm - forearm Sensory to - back of arm - back of forearm - dorsum of hand FORMATION:- continuation of Posterior Cord Root value: C5-C8 & T1 Largest branch of Brachial Plexus

79. 79 RADIAL NERVE: COURSE Descends behind 3 rd part of Axillary artery & later behind brachial art .

80. 80 In axilla anterior to Subscapularis & tendons of LD & T Major

81. 81 Leaves axilla thru triangular space along with Profunda brachii

82. 82 arm At first Lies bt long & medial heads of Triceps. Passes obliquely and enters spiral groove across post surf of humerus bt lateral & medial heads of Triceps. Here it covered by lat head. Enter anterior compartment

83. 83 Showing relation of radial nerve to humerus and vessels

84. 84 RADIAL NERVE: COURSE con’td Descends bt Brachialis & Brachioradialis ( proximally ) and ECRL ( distally ) Anterior to lateral Epicondyle - Divides into terminal branches: a) Superficial branch b) Posterior Interosseous nerve (Deep br)

85. 85

86. 86 Ant. to lat. Epicondyle – Divides into terminal branches : Post. Interosseous nerve (Deep branch) Superficial branch

87. 87 Superficial branch descends along radial border of forearm. Crosses anatomical snuff box Reach back of hand Sensory to dorsum of hand (lat. 2/3rd) small area over palm. Lateral 3 1/2 fingers short of nail beds Flexor aspect

88. Anatomical snuff box 88

89. 89 Deep branch Pierces Supinator enters extensor Compt of forearm. Flexor aspect

90. 90 Deep branch Supplies extensors of forearm. Supinator ECRB, (BR, ECRL??) ED, EDM, ECU, AbPL, EPB, EPL, EI

91. 91

92. 92 RADIAL NERVE: REGION WISE BRANCHES IN AXILLA ( 2 muscular & 1 cut) 1. Post Cutaneous N of arm 2. A br to long head of triceps 3. A br to medial head of triceps

93. IN SPIRAL GROOVE (muscular, cut & articular) Lower lat cut N of arm Post cut N of forearm Lateral & medial head of triceps  ANCONEUS, articular twigs to the elbow jt. 93

94. 94 Branches to triceps Triceps supplied by 4 branches from radial N. Medial head : 2 br , long head : 1 br , lateral head : 1 br

95. 95 BEYOND RADIAL GROOVE ( in the lower part of arm) (Above lateral Epicondyle) Brachialis Lateral part Brachioradialis Extensor Carpi Radialis Longus (ECRL) Elbow joint Then it divides into two branches

96. 96 RADIAL NERVE: REGION WISE BRANCHES IN CUBITAL FOSSA Posterior interosseous nerve (Deep branch) Branch to Supinator Superficial br- supply skin of lat side of dorsum of hand and dorsum of lat 3 ½ fingers proximal to nail beds.

97. 97 RADIAL NERVE: BRANCHES Branches Muscular Cutaneous Articular Muscular Long, medial and lateral head of triceps Anconeus Extensor muscles Cutaneous branch Posterior cut N of arm Lower lateral cut N of arm Posterior cut N of forearm Superficial br of radial (terminal) Articular br Elbow jt Wrist and intercarpal

98. 98 RADIAL NERVE : APPLIED studied under Injury to N in axilla Injury of N in spiral groove Injury of Deep branch – Post interosseous N Injury to superficial br

99. 99 RADIAL NERVE : APPLIED Injury at axilla Causes Extra long crutches (CRUTCH PALSY) Fracture dislocation of upper humerus During reduction of shoulder dislocation Symptoms Motor : All extensors of wrist, elbow, finger paralyzed. Unopposed action of flexors WRIST DROP Fingers can be extended (extension of IP jts) – done by lumbricals and interosseous (supplied by median/ulnar N) Inability to grip objects firmly. (flexors working with decreased mechanical advantage, b’coz extension at wrist is essential for stretching prior to flexion of digits)

100. 100 WRIST DROP unopposed action of flexors at wrist and elbow .

101. 101 WRIST DROP unopposed action of flexors at wrist and elbow.

102. 102 RADIAL NERVE : APPLIED Sensory Loss of sensation over posterior surface of arm, forearm and lower lateral surface of arm Hand – dorsum lateral part Digits – lateral 31/2 digits upto nail beds, dorsal surface

103. 103 Sensory loss in radial nerve injury

104. 104 RADIAL NERVE : APPLIED Injury of N in Spiral groove Causes Fracture of middle shaft of humerus Pressure on Nerve – Saturday Night palsy Operating table edge Prolonged use of tourniquet Motor Triceps not affected, WHY ??? Extension of elbow not impaired WRIST DROP Sensory Back of forearm, dorsum of hand- lateral part Digits – lateral 31/2 upto nailbed

105. 105 RADIAL NERVE : APPLIED Injury to Deep br – Posterior interosseous N Causes Fracture of upper radius Dislocation of head of radius Penetrating wound of upper forearm Motor Brachioradialis, ECRL escapes injury. Other extensors paralyzed Effect at wrist : Extension possible but with radial deviation ( be’coz ECRL escapes injury, ECU, ECRB paralyzed) No sensory loss (Deep br purely motor)

106. 106 RADIAL NERVE : APPLIED Injury at Superficial br Superficial br superficially present on wrist Causes Compression by Tight bracelets, watch straps, plaster casts, hand cuffs etc No motor loss Sensory loss Hand – dorsum lateral ½ Digits – dorsum lateral 31/2 up to nail beds Sensory loss may be minimal and may present only on dorsum of knuckle of index finger Summary If triceps paralyzed – injury at axilla BR paralyzed with normal triceps – injury at radial groove If BR and triceps both normal – injury beyond lateral epicondyle

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