1. Nerve injury I By
Prof. Dr. Kawther Ahmed
Prof. Dr. Kawther Ahmed

2. INTEDED LEARNING OUTCOMES (ILOs)
At the end of the lecture students will be able to:
Describe the cause, muscle affected and the deformity resulting from the injury of:
C5 and C6 (upper trunk lesion).
Tearing of nerve roots C8 and T1 (lower trunk lesion).
Injury of the radial nerve and describe how to test for the integrity of the sensory and motor functions of the nerve.
ILOs
Prof. Dr. Kawther Ahmed

3. Lesions of brachial plexus
Prof. Dr. Kawther Ahmed

4. Complete lesion of brachial plexus
* Cause of injury: rare, as in sever trauma
* Results
1. Motor paralysis of all muscles of upper limb except 2 muscles:
a. Trapezius (as it is supplied by spinal part of accessory nerve).
b. Levator scapulae (as it is also supplied by C4 nerve).
2. Sensory loss of all sensations of the whole upper limb except 2 areas:
a. Tip of shoulder (as it is also supplied by C4 nerve).
b. Floor of axilla (as it is also supplied by T2 nerve).
Prof. Dr. Kawther Ahmed

5. Upper Trunk lesion (Erb’s Paralysis)
Erb’s point
Site of injury: Erb’s point
Cause of injury: over extension of the head from the shoulder which is commonly a birth injury or due to fall on shoulder.
Nerve roots involved: Mainly C5 and partly C6.
Affected nerves:
Suprascapular nerve.
Nerve to subclavius.
Axillary nerve.
Musculocutaneous nerve.
Prof. Dr. Kawther Ahmed

6. Upper Trunk lesion (Erb’s Paralysis)
Motor loss
Abductors of the arm (Supraspinatus & deltoid)
lateral rotators of the arm (Infraspinatus & teres minor)
3. Flexors of the elbow (Brachialis &)
4. Supinators of the arm (supinator and biceps brachii).
Deformity: Policeman’s tips position or Porter’s tips hand
The arm: hangs by the side being adducted and medially rotated.
The forearm: is extended and pronated.
Prof. Dr. Kawther Ahmed

7. Lower Trunk lesion (Klumpke's Paralysis)
Site of injury: Lower trunk of brachial plexus.
Cause of injury:
1- Birth difficulty.
2- Over stretch of the arm.
Nerve roots involved: Mainly T1 and partly C8.
Motor effect: paralysis of:
All intrinsic muscles of hand; mainly lumbricals and interossei.
Ulnar flexors of wrist & fingers.
Prof. Dr. Kawther Ahmed

8. Lower Trunk lesion (Klumpke's Paralysis)
Deformity: Complete claw hand:
Caused by a combined ulnar and median nerve lesion
Sensory loss:
on the medial side of the arm. If C8 is also involved, the sensory loss extends on the medial side of forearm, hand and medial 2 fingers.
* Autonomic loss: If the proximal part of the ventral ramus of T1 is injured, Horner’s syndrome
(ptosis, miosis, enophthalmos and anhydrosis) takes place.
Prof. Dr. Kawther Ahmed

9. Radial Nerve Injury A. Lesion in axilla: Causes:
1- Bad fitting of the upper end of a crutch pressing the nerve up (crutch palsy).
2- Drunken person falling asleep with one arm over the back of a chair (Saturday night’s palsy
or sleep palsy).
3- Fracture and dislocation of the proximal end of the humerus.
Prof. Dr. Kawther Ahmed

10. Radial Nerve Injury Motor effect: paralysis of: Sensory loss:
1- Triceps & anconeus (loss of elbow extension)
2- Brachioradialis & supinator ????
3- Long extensors of wrist and fingers
Deformity: wrist or hand drop & finger drop
There is disability to grip firmly.
Sensory loss:
On the posterior surface of the lower part of the arm.
A narrow strip on the back of the forearm.
Lateral 2/3 of the back of the hand.
Lateral 3½ fingers up to the middle phalanges.
Prof. Dr. Kawther Ahmed

11. Radial Nerve Injury B. Lesion in spiral groove: Deformity: Causes:
Fracture of the middle of the shaft of the humerus.
Using a tourniquet to the arm for a long time.
Motor effect: Paralysis of long extensors of the wrist and fingers
Deformity:
wrist drop & finger drop.
Sensory loss: over the lateral 2/3 of the dorsum of the hand and the dorsal surface of the roots of lateral 3½ fingers.
Prof. Dr. Kawther Ahmed

12. Radial Nerve Injury Causes: Motor effect: paralysis of:
C. Lesion at superior radioulnar joint (Posterior interosseous nerve)
Causes:
1- Fracture of proximal end of radius.
b- Dislocation of head of radius.
Motor effect: paralysis of:
1- The muscles of the back of the forearm except anconeus, brachioradialis and extensor carpi radialis longus
Deformity: fingers drop.
2- The extensors carpi radialis longus can produce and maintain extension of the wrist (no wrist drop).
Sensory loss: No sensory loss.
Prof. Dr. Kawther Ahmed

13. Radial Nerve Injury Over the lateral 2/3 of the dorsum of the hand
D. Lesion in the forearm (superficial branch of the radial nerve):
This leads only to sensory loss
Over the lateral 2/3 of the dorsum of the hand
The dorsal surface of the roots of the lateral 3½ fingers.
Prof. Dr. Kawther Ahmed

14. Case study
After a difficult forceps delivery of a male infant, the baby presents later with his left arm was medially rotated and adducted, while the forearm was pronated and extended.
Name the deformity.
What is the clinical condition resulting in this deformity?
Injury to which part of brachial plexus is responsible for this condition?
Why the forearm is pronated?
Prof. Dr. Kawther Ahmed

15. Prof. Dr. Kawther Ahmed