Term
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Definition
Axon degeneration with schwann cell preservation
Result: partial or complete block of conduction across a segment of a nerve |
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Term
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Definition
Segmental axon degeneration with schwann cell preservation
Result: distant wallerian degeneration occurs |
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Term
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Definition
Axonal transection before degeneration
Result: Axonal regeneration can not occur. |
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Term
| Sunderland System of Nerve Damage |
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Definition
1st Grade:Nerve in continuity, compression, ischemia. recovery 2-3weeks.
2nd Grade: injury to axon but supporting structures intact, WD occurs, Recovery 1mm/day
3rd Grade: Endoneurium disrupted. Epineurium, perineurium intact. Recovery poor to complete depending on intrafascicular fibrosis
4th Degree: Interruption of all neural and supporting elements. Epineurium intact. Nerve enlargement occurs.
5th Degree: Complete transection with loss of continuity. |
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Term
| What causes constriction, compression or stretching of neurovascular structures? |
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Definition
Myofascial banding
Fibrous adhesions
Osteophytes
SOL |
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Term
| Progression of nerve degeneration from compression |
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Definition
Ischemia
focal demyelination
Force exerted on myelin sheath priduces thinning and irregularities in myelin deposition
Damage blood-nerve barriers, increasing intraneural permeability to degradative macromolecules
Conduction Block
Terminal axon Infarction
Wallerian Degeneration |
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Term
| Risk factors of nerve injury |
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Definition
Stenosis
Metabolic abnormality
Chronic nutritional deficiency
Vascular insufficency
Toxic Exposure
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Term
| Why is cutaneous sensation more likely to recover than motor function from denervation? |
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Definition
Cutaneous sensation: pain / touch / temp, carried by small afferent fibres
Motor carried by large myelinated nerves
Also receptor : axon ratio
Pacinian Corpuscles (HF vibration), 1:1
Meissners Corpuscle (LF vibration), 1:multiple
Merkels cells (touch and pressure), multiple:1 |
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Term
| Predisposing Factors to Peripheral Neuropathy |
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Definition
RA
Diabetes
Thyroid Disease
Uremia
Respiratory Insufficency
HIV-1 |
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Term
| How does RA cause peripheral neuropathy? |
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Definition
Direct compression from inflammation around soft tissues
Commonly, median nerve in carpal tunnel
Ulnar nerve at the elbow
Posterior tibeal nerve at popliteal space
Common peroneal nerve, at tibiofibular articulation and fibular head. |
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