Peripheral Nerve Injury Flashcards
Content: Neural Structures in the PNS (4)
- Muscle spindle receptors
- GTO
- Motor Endings
- Axons
Q: What do the rami communicantes connect with?
Sympathetic Ganglia
Diagram: Axon Characteristics Table
Content: Mechanisms of Nerve Injury (5)
- Compression or crush
- Laceration
- Stretch
- Radiation
- Electricity
Content: Sedden’s Classification of Nerve Injury (3)
- Neurpraxia
- Axonotmesis
- Neurotmesis
Content: Neurapraxia (3)
- Low severity injury
- Nerve remains intact but electrical conduction is interrupted by ischemia/compression
- Secondary injuries can be caused by vascular damage leading to intrafascicular edema
Content: Axonotmesis (3)
- Axon is disrupted by myelin sheath is intact
- Typically due to a crush injury
- If neuronal tubules are maintained, regeneration/restoration of sensory/motor may return
Content: Neurotmesis (3)
- Loss of nerve conduction and damage to surrounding nerve trunk CT
- In extreme cases complete nerve transection occurs
- Commonly a neuroma forms over the proximal stump preventing normal regeneration
Diagram: Seddon’s Classification of Nerve Injury
Diagram: Summary of Seddon’s Classification
Content: Any Peripheral Nerve Injury in Extremity Trauma by %
- After LE Fx
- After UE wound
- After Crush Injury
- 1.77
- 1.85
- 1.91
Q: What are the most common peripheral nerve injuries following extremity trauma?
Radial/Ulnar after Humerus Fx (1.03%) and Sciatic/lumbosacral plexus/femoral after Pelvis Fx (1.76%)
Diagram: Signs and Symptoms of Mixed Peripheral Nerve Lesions (Axonotmesis or Neurotmesis)
Q: What conditions can cause peripheral nerve injury due to compression of the nerve roots? (4)
- Degenerative disc/joint disease
- Spondylolisthesis
- Spine deviations
- Narrowing of the intervertebral foramen
Q: Compression of the following nerves caues what UE syndrome?
- Brachial Plexus
- Ulnar n.
- Radial n.
- Medial n.
- Thoracic outlet syndrome
- cubital tunnel syndrome or compression on tunnel of Guyon
- Radial n. compression
- Carpal Tunnel Syndrome