NERVE INJURIES OF UPPER LIMB By Dr. Abdul Waheed Ansari Chairperson & Prof. Anatomy RAKCOMS 5/26/2016 1

After completion of this CBL the students are able to: Debate the sequel of loss of function due to radial, ulnar and median nerves damages. Identify the clinical cases involved in accidents resulting in winging of scapula, deltoid flattening, wrist drops, and claw hand deformity. Illustrate the brachial plexus formation and terminal branches. name the muscles undergoing loss of function due to injuries to above nerves. 2 5/26/2016

All nerve supply to upper limb comes from brachial plexus Formation of Brachial plexus:- 3 5/26/2016

Brachial plexus Roots C5+C6+C7+C8+T1 Trunks:- Upper trunk-C5+C6 Middle trun-C7 Lower trunk-C8+T1 Divisions:- 3 anterior+3 posterior Cords:- Lateral cord Medial cord Posterior cord Major branches:- Axillary Musculocutaneous Median Ulnar Radial 4 5/26/2016

Brachial Plexus Injuries (upper lesions) These are caused by the excessive displacement of the head to the opposite side Depression of the shoulder on the same side This causes excessive traction of C5 and C6 roots of the plexus 5/26/2016 5

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Muscles to be Paralyzed Supraspinatus (Abductor of shoulder) Infraspinatus (lateral rotator of shoulder) Biceps brachii (flexor of elbow) Coracobrachialis (flexor of shoulder) Deltoid (Abductor of shoulder) Teres minor (lateral rotator of shoulder) 5/26/2016 7

Erb-Duchenne Palsy The limb hangs limply by the side likened to a waiter or porter hinting for a tip There will be a loss of sensation down the lateral side of arm 5/26/2016 8

9 5/26/2016 CLINICAL CASE This 2216 g boy was delivered via vaginal breech at 40 weeks to a G2P1 mother. Following an episiotomy and gentle stretching, the hips and legs were delivered (followed by the arms and shoulders) but the head was ‘stuck’, requiring forceps. There was mild asphyxia. A left Erb’s palsy was noted with no contractions in triceps, biceps and deltoids, but good power in all wrist movements. Recovery was marginal and at eight months a magnetic resonance image (MRI) suggested avulsion of cervical roots C5 and C6. At six years of age, he has no function and marked wasting of the right deltoid and pectoralis major. He was independent for virtually every activity but he liked to receive help putting his shirt on. He could not bring his left hand to the top of his head without ‘throwing’ the arm up. Unfortunately, he will always be mildly handicapped.

Brachial Plexus Injuries (Lower lesions) Are usually a traction injuries caused by excessive abduction of the arm The first thoracic nerve is usually torn The hand has a clawed appearance caused by hyperextension of metacarpophalangeal joints & flexion of interphalangeal joints 5/26/

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Brachial Plexus Injuries (Lower lesions) Loss of sensation will occur along the medial side of the arm Lower lesions can also be produced by a presence of a cervical rib or malignant metastases from the lungs in the lower deep cervical lymph nodes 5/26/

Axillary Sheath A brachial plexus nerve block can be obtained by injecting a local anesthetic The position of the sheath can be verified by feeling the pulsations of the 3 rd part of the axillary artery 5/26/

Injuries of Long Thoracic Nerve Can be injured by blows to or pressure on the posterior triangle of the neck Serratus anterior is paralyzed The patient feels difficulty in raising the arm The vertebral border & inferior angle of scapula protrude posteriorly Known as winged scapula 5/26/

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Injuries of Axillary Nerve Can be injured by the pressure of a badly adjusted crutch pressing upward into the armpit It is vulnerable during the downward displacement of the humeral head in shoulder dislocations or fractures of the surgical neck of the humerus Paralysis of deltoid and teres minor muscles results 5/26/

Axillary Nerve Loss of skin sensation over the lower half of the deltoid muscle Paralyzed deltoid wastes rapidly Underlying greater tuberosity can be palpated Abduction of the shoulder is impaired Paralysis of teres minor is not recognized clinically 5/26/

Injuries of Radial Nerve Can be injured by: Pressure of badly fitting crutches Drunkard falling asleep with one arm over the back of a chair Fractures or dislocation of the proximal end of the humerus 5/26/

Findings in Radial N. Injury Triceps, anconeus and long extensors of the wrist are paralyzed Unable to extend the elbow joint, wrist joint and fingers Wrist drop or flexion of wrist occurs Unable to flex the fingers firmly for gripping Brachioradialis & supinator are paralyzed 5/26/

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Sensory Findings Little loss of skin sensation over posterior surface of lower part of the arm Sensory loss on the lateral part of dorsum of the hand Sensory loss on the dorsal surface of the roots of the lateral 3 & ½ fingers 5/26/

In the Spiral Groove Radial nerve can be injured in the spiral groove at the time of fracture of shaft of the humerus Wrist drop occurs Sensory loss on the dorsal surface of the roots of the lateral 3 & ½ fingers 5/26/

Deep Branch of Radial Nerve Can be damaged in the fracture of the proximal end of radius or during dislocation of the radial head No wrist drop as extensor carpi radialis longus is undamaged No sensory loss as this is a motor nerve 5/26/

Injuries of Musculocutaneous Nerve Rarely injured due to its protected position beneath the biceps brachii muscle If injured high up in the arm, the biceps & coracobrachialis are paralyzed & brachialis is weakened Sensory loss along the lateral side of the forearm occurs 5/26/

Injuries of Median Nerve Can be injured: Occasionally in the elbow region in supracondylar fractures of the humerus Commonly injured by stab wounds or broken glass just proximal to the flexor retinaculum Here it lies between the tendons of flexor carpi radialis and flexor digitorum superficialis 5/26/

Injury at Elbow (motor) Pronator muscles of forearm, long flexor muscles of the wrist & fingers will be paralyzed Forearm is kept in supine position Wrist flexion is weak & accompanied by adduction No flexion at interphalangeal joints of index & middle fingers 5/26/

Injury at Elbow (motor) When the patient tries to make a fist, the index & middle fingers tend to remain straight Only ring & little fingers flex Flexion in these fingers is weakened by the loss of the flexor digitorum superficialis 5/26/

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Injury at Elbow (motor) Flexion of terminal phalanx of thumb is lost because of paralysis of flexor policis longus The thumb is laterally rotated and adducted Muscles of thenar eminence are paralyzed The hand looks flattened and ape like 5/26/

Injury at Elbow (sensory) Skin sensation is lost on the palmar aspect of the lateral 3 & ½ fingers Sensory loss occurs on the skin of the distal part of the dorsal surfaces of the lateral 3 & ½ fingers Total area of anesthesia is less 5/26/

Injury at Elbow (vasomotor changes) The skin areas involved in sensory loss are warmer and drier than normal Arteriolar dilatation and absence of sweating resulting from loss of sympathetic control 5/26/

Injury at Elbow (Trophic changes) In long standing cases: Skin is dry and scaly Nails crack easily Atrophy of the pulp of the fingers 5/26/

Injury at Wrist Almost all the clinical findings are same as injury of the median nerve at elbow In addition a delicate pincer like movement is not possible 5/26/

Carpal Tunnel Syndrome The carpal tunnel is formed by the concave anterior surface of carpal bones and closed by flexor retinaculum Clinically, the syndrome consists of a burning pain or pins & needles along the distribution of the median nerve Lateral 3 & ½ fingers are involved 5/26/

Carpal Tunnel Syndrome The exact cause is difficult to determine Condition is relieved by decompressing the tunnel by making a longitudinal incision through the flexor retinaculum 5/26/

Injury to the Ulnar Nerve (motor at elbow) Flexor carpi ulnaris & medial half of flexor digitorum profundus are paralyzed In a tightly clenched fist the tightening of the tendon of profundus is absent Profundus tendon to the ring & little fingers will be functionless Terminal phalanges of these fingers fail to flex properly 5/26/

Injury to the Ulnar Nerve (motor at elbow) Flexion of wrist joint will result in abduction due to paralysis of flexor carpi ulnaris Small muscles of hand will be paralyzed except the muscles of thenar eminence and first 2 lumbricals Adductor pollicis longus is paralyzed so the adduction of thumb is not possible 5/26/

Injury to the Ulnar Nerve (motor at elbow) Metacarpophalangeal joints become hyperextended due to the paralysis of lumbrical and interosseous muscles Interphalangeal joints are flexed due to the same reason as mentioned above Dorsum of hand will show hollowing due to the wasting of dorsal interosseous muscles 5/26/

Injury to the Ulnar Nerve (sensory at elbow) Loss of skin sensation of anterior & posterior surfaces of the medial 3 rd of the hand and medial 1 & ½ fingers The skin areas involved in sensory loss are warmer and drier than normal Arteriolar dilatation and absence of sweating resulting from loss of sympathetic control 5/26/

Injury to the Ulnar Nerve (motor at wrist) Small muscles of the hand will be paralyzed Claw hand is more obvious as flexor digitorum profundus is not paralyzed Marked flexion of the terminal phalanges occur 5/26/

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Injury to the Ulnar Nerve (sensory at wrist) The sensory loss is usually confined to the palmar surface of medial 3 rd of the hand and the medial 1 & ½ finger Trophic changes are same as that injuries of ulnar nerve at elbow Unlike median nerve injuries, lesions of ulnar nerve leave a relatively efficient hand Pincer like action is good 5/26/

Summary of upper limb nerve injuries Erb’s palsy------upper trunk Klumpke’s palsy---- lower trunk Winging of scapula---- long thoracic nerve Ape’ s hand---- median nerve---- supracondylar fracture Wrist drop Radial nerve---fracture of spiral groove Claw hand-----ulnar nerve----- fracture of medial epicondyle 5/26/