Periphral nerve injury

Peripheral nerve damage affecting the upper extremities can vary widely in cause and extent.
Many disorders, ranging from mild carpal tunnel syndrome to severe brachial plexopathy, need to be considered in a patient presenting with pain, sensory loss, or weakness involving the shoulder, arm, or hand.

1. Periphiral nerve injuries of the upper limb Prepared by: Dr . Abdullah K. Ghafour 3rd year IBFMS trainee Supervised by: Dr. Hamid Ahmed Jaff

2. INTRODUCTION Peripheral nerve damage affecting the upper extremities can vary widely in cause and extent. Many disorders, ranging from mild carpal tunnel syndrome to severe brachial plexopathy , need to be considered in a patient presenting with pain, sensory loss, or weakness involving the shoulder, arm, or hand.

3. ANATOMY Nerve roots emerge from the spinal cord formed by ventral (anterior rami) of cervical spinal nerves C5-C8 and thoracic spinal nerves T1 form brachial plexus. Brachial plexus is responsible for cutaneous (sensory) and muscular (motor) innervation of the entire upper limb.

4. ANATOMY 5 main nerves arise from brachial plexus : Axillary nerve (C5,C6) Musculocutaneous nerve (C5,C6,C7) Radial nerve (C5,C6,,C7,C8 &T1) Median nerve (C5,C6,,C7,C8 &T1 ) Ulnar nerve (C8 &T1)

5. Brachial Plexus

6. PATHOLOGY Nerves can be injured by ischaemia , compression, traction, laceration or burning. Damage varies in severity from transient and quickly recoverable loss of function to complete interruption and degeneration. There may be a mixture of types of damage in the various fascicles of a single nerve trunk.

7. Classification of Nerve Injuries Seddon’s classification (1942) : Neurapraxia ; mechanical pressure causing segmental demyelination Axonotmesis ; axonal interruption with loss of conduction but the nerve is in continuity and the neural tubes are intact. Neurotmesis ; division of the nerve trunk with loss of continuity. Brain’s classification (1943) : Localised degeneration of the myelin sheaths Complete interruption of axons with Preservation of supporting structures (Schwann tubes, endoneurium , perineurium ) All essential parts destroyed, Interruption can occur without apparent loss of continuity

8. Classification of Nerve Injuries III. Sunderland classification (1978): First degree injury ; This embraces transient ischaemia and neurapraxia Second degree injury ; axonal distruption ( Axonotmesis ) Third degree injury ; The endoneurium is disrupted but the perineurial sheaths are intact and internal damage is limited. Fourth degree injury Only the epineurium is intact. Fifth degree injury The nerve is divided.

9. Diagnosis- history  History Which nerve ? What level ? What is the cause ? What degree of injury ? Old or fresh injury ?

10. Diagnosis- examination   Motor: All muscles distal to the injury – paralyzed & atonic Atrophy : 50 -70 % in 1st two months Striations & motor end plate configurations retained for 12 – 18 months (critical limit of delay ) Sensory loss usually follows a definite anatomical pattern, although factor of overlap from adjacent nerves may be present Autonomous zone Weber 2 point discrimination test Tinel’s sign

11. Diagnosis- examination   Reflex ; Abolishes all reflexes transmitted by that nerve, either afferent or efferent arc. Complete & incomplete lesion. So , not a reliable guide to injury severity. Autonomic : Loss of sweating Loss of pilomotor response Vasomotor paralysis in autonomous zone Others: Trophic Changes Esp . hand and feet Skin – thin, glistening, breaks easily to form ulcers Fingernails – Ridged , distorted and brittle Osteoporosis (Reflex sympathetic dystrophy)

12. Diagnosis- examination

13. Brachial plexus injury In upper plexus injuries (C5 and 6) the shoulder abductors and external rotators and the forearm supinators are paralyzed. Sensory loss involves the outer aspect of the arm and forearm. Erb-Duchenne palsy: ( Waiter’s tip position)The limb hangs by the side adducted and medially rotated by unopposed pectoralis major. The forearm extended and pronated because the action of biceps is lost .

14. Brachial plexus injury Pure lower plexus injuries ; ( klumpke pulsy ) are rare . Affects T1 nerve root. Wrist and finger flexors are weak and the intrinsic hand muscles are paralysed . Sensation is lost in the ulnar forearm and hand. If the entire plexus is damaged, the whole limb is paralysed and numb.

15. Musculocutaneous nerve injury SENSORY SUPPLY skin of lateral forearm MOTOR SUPPLY anterior compartment of arm (BBC) biceps – flexes elbow, supinates forearm brachialis – flexes elbow coracobrachialis  – flexes and adducts the arm at the glenohumeral joint COMMON INJURIES musculocutaneous nerve injuries are rare, as the nerve is protected beneath the bulk of the biceps muscle it may be damaged by stab wounds to the upper arm

16. MCN injury manifestations SENSORY LOSS numbness over lateral forearm MOTOR DEFICIT paralysis of anterior compartment of arm – very weak elbow flexion and weak forearm supination absent biceps reflex DEFORMITY wasting of anterior compartment of arm elbow usually held in extension with forearm pronated

17. Axillary nerve injury Sensory function : sensation of an oval shaped area over the lateral shoulder “ sergeant's patch “ Motor function : it innervates the deltoid (shoulder abduction) and teres minor (shoulder external rotation) muscles . Common causes of injury : Trauma, usually with shoulder dislocation or humeral fracture, iatrogenic

18. Axillary nerve injury manifestations Sensory loss : sharply-defined region of sensory loss over the lateral shoulder “sergeant's patch “ Motor loss : The patient complains of shoulder ‘weakness’. Although abduction can be initiated (by supraspinatus), it cannot be maintained. Deformity: wasting of the deltoid

19. Radial nerve injury Sensory function : posterior arm and forearm , lateral ⅔ of dorsum of hand and proximal dorsal aspect of lateral 3½ fingers Motor function : posterior compartment of the arm and forearm Common causes of injury : fractures of proximal humerus , shaft of humerus or radius, stab wounds to antecubital fossa, forearm or wrist

20. Radial nerve injury manifestations Low lesions; The patient complains of clumsiness and, on testing, cannot extend the MCP joints of the hand . In the thumb there is also weakness of extension. Wrist extension is preserved. High lesions ; There is an obvious wrist drop, due to weakness of the radial extensors of the wrist, as well as inability to extend the MCP joints or elevate the thumb. Sensory loss is limited to a small patch on the dorsum around the anatomical snuffbox . Very high lesions ; In addition to weakness of the wrist and hand, the triceps is paralysed and the triceps reflex is absent.

21. Median nerve injury Sensory function : Skin over thenar eminence, lateral ⅔ palm of hand and palmar aspect of lateral 3½ fingers Motor function : all muscles of anterior compartment of forearm except flexor carpi ulnaris and the medial two parts of flexor digitorum profundus Common causes of injury : supracondylar fractures of humerus , compression by carpal tunnel syndrome

22. Median nerve injury manifestations Low lesions ; The patient is unable to abduct the thumb, and sensation is lost over the radial three and a half digits. In longstanding cases the thenar eminence is wasted and trophic changes may be seen . High lesions; in addition, the long flexors to the thumb, index and middle fingers, the radial wrist flexors and the forearm pronator muscles are all paralysed ‘pointing sign’.

23. Ulnar nerve injury Sensory function : skin over hypothenar eminence, medial ⅓ palm of hand ,palmar aspect of lateral 1½ fingers Motor function : two muscles of anterior compartment of forearm , and most of the intrinsic muscles of the hand Common causes of injury : supracondylar fractures of humerus , compression cubital tunnel in the elbow.

24. Ulnar nerve injury manifestations Low lesions; There is numbness of the ulnar one and a half fingers. The hand assumes claw hand deformity with hyperextension of the MCP joints of the ring and little fingers, due to weakness of the intrinsic muscles. Finger abduction is weak and this, together with the loss of thumb adduction , makes pinch difficult . High lesions ; The hand is not markedly deformed because the ulnar half of flexor digitorum profundus is paralysed and the fingers are therefore less ‘clawed’ (the ‘ high ulnar paradox’ ). Otherwise, motor and sensory loss are the same as in low lesions.

25. Treatment Nonoperative observation with sequential EMG indications neuropraxia (1st degree) axonotmesis (2nd degree) Operative surgical repair indications neurotomesis (3rd degree) nerve grafting indications defects > 2.5 cm type of autograft ( sural , saphenous, lateral antebrachial , etc ) no effect on functional recovery

26. Treatment Indications for surgery: When a sharp injury has obviously divided a nerve . When abrading, avulsing or blast wounds have rendered the condition of nerve unknown. When a nerve deficit follows a blunt or closed trauma & no clinical or electrical evidence of regeneration has occurred after an appropriate time. When a nerve deficit follows a penetrating wound as stab or low velocity gunshot wound, part observed for evidence of nerve regeneration for appropriate time.

27. Treatment Types of Nerve Repair : Endoneurolysis Partial Neurorrhaphy Neurorrhaphy Epineural Epi-perineural Perineural Nerve grafting

28. Treatment Time of Surgery: Primary repair : First 6 – 8 hours Delayed primary repair : First 7 – 18 days Secondary repair : > 3 weeks

29. Treatment Factors that influence regeneration after neurorrhaphy : 1 . Age of patient 2 . Gap between nerve ends 3 . Delay between time of injury and repair 4 . Level of injury 5 . Condition of nerve ends 6 . Experience & technique of surgeon

30. THANKS THANKS TIME FOR QUESTIONS