[36] Other Nerve Injuries Flashcards
What are the nerve roots of the radial nerve?
C5-T1
What do low lesions of the radial nerve affect?
Posterior interosseous nerve
What causes low lesions of the radial nerve?
Fracture around the elbow or forearm, e.g. fracture of the head of the radius
What does a lesion of the posterior interosseous nerve produce?
Loss of extension of the CMC joints, producing finger drop
No sensory loss
What can cause high lesions of the radial nerve?
Fracture of shaft of the humerus where the nerve is in the radial groove
What results from high lesions of the radial nerve?
Wrist drop
Loss of sensation to dorsum of the thumb root (snuff box)
What can cause very high lesions of the radial nerve?
Compression in axilla, e.g. crutches
What results from a very high lesion of the radial nerve?
Paralysis of the triceps and wrist drop
What are the roots of the ulnar nerve?
C8-T1
Where can the ulnar nerve get injured in the elbow?
Cubital tunnel
Where can the ulnar nerve get injured in the wrist?
Guyon’s canal
What are the effects of ulnar nerve palsy?
Intrinsic hand muscle paralysis, leading to claw hand
Weakness of finger ad/abduction
Sensory loss over little finger
What is the ulnar paradox?
A lesion at the elbow has less clawing, as FDP is paralysis which decreases flexion of 4th and 5th digits
How can the ulnar nerve be tested?
Cross fingers
Look for Froment’s sign?
What is Froment’s sign?
Flexion of the thumb IPJ when trying to hold onto paper held between the thumb and finger
What does Froment’s sign indicate?
Weak adductor policis
What are the nerve roots for the median nerve?
C5-T1
What is produced when there is an injury to the median nerve above the antecubital fossa?
Can’t flex the index finger IPJs
Can’t flex terminal thumb phalanx
Loss of sensation in median distribution
What is affected when there is an injury to the median nerve at the wrist?
Typically affects the abductor pollicis brevis
When else might the median nerve get injured?
Carpal tunnel syndrome
