Professional and Linguistic Assessments Board (PLAB) Practice Exam

What characterizes the difference between sensation in the lateral leg and medial leg?

1. Bilateral distribution

2. Different contributing nerves

3. Same nerve root

4. Symmetrical distribution

The correct answer is: Different contributing nerves

The distinction in sensation between the lateral and medial aspects of the leg is primarily determined by the different contributing nerves that serve these areas. The lateral leg is primarily innervated by the common peroneal nerve, which branches from the sciatic nerve, while the medial leg is innervated by the saphenous nerve, a branch of the femoral nerve. This difference in nerve supply leads to variations in sensory perception between these two regions. The other options do not accurately reflect the nature of the sensory differences. Bilateral distribution refers to sensations being similar on both sides of the body, which is not the case here. Same nerve root implies that both areas would be served by the same nerve roots, which is not true. Symmetrical distribution suggests that sensations would be uniform on both sides of the body or within each area, which also does not apply in this context due to the differing nerve innervation.