In each part of this question, list clinical examination findings for each of the two underlined conditions that would help you to distinguish between them:
- A myopathy or a neuropathy as being the cause of weakness in all limbs of a patient
- Wasting is late sign
- Usually proximal weakness
- Reflexes preserved until late
- Normal sensory exam
- May be muscle tenderness
- Wasting earlier
- May be fasciculations
- Often peripheral distribution
- Loss of reflexes
- May be abnormal sensory exam
This comes down to basic common sense.
If the nerves are healthy, and the muscles are to blame,
- The sensory supply should be preserved
- The reflexes should be preserved
- Weakness should be proximal - that is where the bigger muscles are, and the weakness there will be more obvious.
- There should be no fasciculations
- There may be myocardial involvement (skeletal myopathies tend to be associated with cadiomyopathy)
- The muscles involved may be painful and tender(as in myositis)
This question has been repeated. Its doppelganger, Question 3.1 from the first paper of 2010, has a much better-organised college answer.
Chapter 57 (pp. 617) Neuromuscular diseases in intensive care by George Skowronski and Manoj K Saxena
Young, G. Bryan, and Robert R. Hammond. "A stronger approach to weakness in the intensive care unit." Critical care 8.6 (2004): 416.
Dhand, Upinder K. "Clinical approach to the weak patient in the intensive care unit." Respiratory care 51.9 (2006): 1024-1041.