Movement symposium 2: Peripheral nerve lesions Flashcards
What is Erb’s palsy?
Common in newborn when there is excessive stretching of the neck during delivery causing damage to C5, C6 nerve roots.
What are the symptoms of Erb’s palsy?
Paralysis of muscles of shoulder and arm supplied by C5, C6 e.g.
- Arm hangs limply by the side
- “waiter’s tip” position
- Adducted shoulder
- Medially rotated arm
- Extended elbow
- Pronated forearm
What is the explanation for the muscular symptoms of Erb’s palsy?
Loss of abductors e.g. Deltoid (axillary C5,6)
Loss of lateral rotators - infraspinatus (suprascapular C5,6) and teres minor (axillary C5,6)
Loss of flexion and supination by biceps (musculocutaneous nerve C5,C6,C7)
Loss of flexion by brachialis (musculocutaneous nerve C5,C6,C7)
How might Erb’s palsy occur in an adult or child?
Child - brachial plexus stretched during birth
Adult - fall on the shoulder
Both result in extreme abduction at the neck
What is Klumpke’s palsy?
Damage to inferior trunk of brachial plexus (C8, T1 – ulnar nerve)
Less common than Erb’s palsy
Occurs in newborns where the baby’s upper limb is pulled excessively during delivery
Paralysis of the majority of the intrinsic hand muscles (and ulnar flexors of the wrist and digits)
Imbalance of the intrinsic & extrinsic muscles leads to hand deformity - Claw hand
What might happen to the hand in Klumpke’s palsy and why?
The extensors primarily extend the metacarpophalangeal joints whilst FDS and FDP inserting into the distal and middle phalanges, flex the interphalangeal joints
Thus in a claw hand there is hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints - claw hand (not to be confused with hand of benediction)
Due to paralysed lumbricals of digits 4 and 5
How might Klumpke’s palsy occur in adults and children?
Children - baby’s upper limb is pulled excessively during birth.
Adult - upper limb is suddenly pulled superiorly e.g. grasping to prevent a fall
What is cubital tunnel syndrome?
- 2nd most common nerve entrapment syndrome
- Cubital tunnel - tendinous arch between the humeral and ulnar heads of flexor carpi ulnaris.
- May be caused by: constricting fascial bands, direct compression, occupational activities from repetitive elbow flexion and extension.
- Same symptoms as Klumpke’s palsy plus elbow pain
- Treatment initially anti-inflammatories then surgery if unresolved
What syndrome may Klumpke’s palsy be associated with and why?
Horner’s syndrome - ptosis, miosis, anhidrosis, vasodilation
Sympathetic neurons supplying the head originate from T1 and may also be damaged by traction
What is radial nerve palsy?
- Injury to radial nerve in spiral groove of humerus results in wrist drop
- Inability to extend the wrist and metacarpophalangeal joints due to paralysis of extensor muscles of the forearm.
- Triceps is usually weakened rather than paralysed
How might median nerve damage occur?
Supra condylar fractures or pronator teres syndrome.
What structures are supplied by the median nerve?
Supplies majority of forearm flexors EXCEPT flexor carpi ulnaris (ulnar) and medial half of flexor digitorum profundus (ulnar + median).
Also supplies thenar eminence and lateral 2 lumbricals of the hand
What might happen to the hand as a result of median nerve injury?
Inability to flex digits 1-3
- Flexor digitorum superficialis and profundus
- Lateral 2 lumbricals
- Flexor pollicis longus
- Thenar eminence
Flexion of digits 4 and 5 weakened but still able to flex including distal interphalangeal joint (ulnar nerve)
When trying to make a fist appear like hand of benediction
What name is given to the motor portion of the the radial nerve and what does it supply?
Posterior interosseous nerve - supplies wrist, finger and thumb extensors.
What name is given to the sensory portion of the radial nerve and what does it supply?
Dorsal sensory nerve - dorsum 1st web space
