Peripheral Nerve Palsies/Injuries Flashcards
What are peripheral nerve injuries also known as?
Palsies
Refers to a range of conditions resulting from damage to the PNS.
Name the three main types of palsy classified using Seddon classification.
- Neuropraxia
- Axonotmesis
- Neurotmesis
What is the definition of Neuropraxia?
Temporary conduction block
Myelin damage with no axon loss.
What is the expected recovery for Neuropraxia?
Complete recovery in days to weeks
What are the NCS findings for Neuropraxia?
Normal conduction distal to lesion; slow/blocked across site
Provide an example of Neuropraxia.
- Saturday night palsy (radial nerve)
- ‘Foot drop’ after prolonged squatting (peroneal nerve)
What is the definition of Axonotmesis?
Axonal disruption with intact connective tissue
Axon and myelin lost, endoneurium intact.
What is the expected recovery for Axonotmesis?
Good but slow recovery
What are the NCS findings for Axonotmesis?
Wallerian degeneration; reduced amplitudes
Provide an example of Axonotmesis.
Crush injury to limb (e.g. sciatic or radial nerve damage)
What is the definition of Neurotmesis?
Complete nerve transection
Axon, myelin, and connective tissue lost.
What is the expected recovery for Neurotmesis?
Poor without surgical repair
What are the NCS findings for Neurotmesis?
No conduction
Provide an example of Neurotmesis.
Iatrogenic injury during surgery (e.g. thyroidectomy damaging recurrent laryngeal nerve)
What is Erb’s palsy associated with?
Upper trunk: C5-C6; birth injury, shoulder trauma
Characterized by ‘waiter’s’ tip.
What is Klumpke’s palsy associated with?
Lower trunk: C8-T1; birth injury, grabbing during fall
Can lead to claw hand +/- Horner’s if T1 affected.
What is the cause of Radial nerve palsy?
Humeral shaft fracture, Saturday night palsy
Results in wrist drop and weak elbow/wrist/finger extension.
What causes Ulnar nerve palsy?
Elbow trauma, entrapment at cubital tunnel
Leads to claw hand, more prominent in ring/little fingers.
What causes Median nerve palsy?
Carpal tunnel, wrist laceration
Results in ape hand and loss of thumb opposition.
What is the cause of Long thoracic nerve palsy?
Trauma, backpack injury
Results in winged scapula.
What causes Axillary nerve palsy?
Shoulder dislocation, surgical neck fracture
Leads to deltoid weakness and numbness over deltoid.
What is the cause of Common peroneal nerve palsy?
Fibular head injury, tight plaster casts
Results in foot droop and sensory loss on dorsum of foot.
What causes Femoral nerve palsy?
Pelvic trauma/surgery
Results in weak knee extension and reduced patellar reflex.
What is the cause of Obturator nerve palsy?
Pelvic surgery
Leads to medial thigh numbness and weak thigh adduction.
