NERVE INJURIES OF UPPER LIMB

1. NERVE INJURIES OF UPPER LIMB Dr. Mujahid Khan

2. 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 or tearing of C5 and C6 roots of the plexus

4. Nerves To be Affected • The suprascapular nerve • The nerve to the subclavius • The musculocutaneous nerve • Axillary nerve • All possess nerve fibers derived from C5 and 6 roots and will therefore be functionless

5. Muscles to be Paralyzed • Supraspinatus (Abductor of shoulder) • Subclavius (depresses the clavicle) • Infraspinatus (lateral rotator of shoulder) • Biceps brachii (flexor of elbow) • Coracobrachialis (flexor of shoulder) • Deltoid (Abductor of shoulder) • Teres minor (lateral rotator of shoulder)

6. 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

7. 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

9. 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

10. Injuries of Long Thoracic Nerve • Can be injured by blows to or pressure on the posterior triangle of the neck • During the surgical procedure of radical mastectomy • Paralysis of the serratus anterior results in the inability to rotate the scapula during the movement of abduction of the arm above a right angle

11. Injuries of Long Thoracic Nerve • The patient feels difficulty in raising the arm • The vertebral border & inferior angle of scapula protrude posteriorly • Known as winged scapula

13. 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

14. 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 recognizable clinically

15. 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

16. 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

18. Sensory Findings • Small 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

26. 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

27. 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

28. 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

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

30. 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. Injury to the Ulnar Nerve(sensory at elbow) • Loss of skin sensation of anterior & posterior surfaces of the medial 3rd 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

38. 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

40. Injury to the Ulnar Nerve(sensory at wrist) • The sensory loss is usually confined to the palmar surface of medial 3rd 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