Home › MCQs › MBBS › Question #10232
Back to Questions
MBBS QUESTION #10232
Question 1
Lambert-Eaton myasthenic syndrome, often paraneoplastic (associated with small cell lung cancer), differs from myasthenia gravis in that its autoantibodies target:
  • Postsynaptic acetylcholine receptors
  • Presynaptic voltage-gated calcium channels, impairing calcium-dependent acetylcholine vesicle release✔️
  • Muscle-specific kinase (MuSK) exclusively
  • The motor end-plate acetylcholinesterase enzyme
Correct Answer Explanation
In Lambert-Eaton syndrome, antibodies against presynaptic voltage-gated calcium channels impair ACh release; unlike myasthenia gravis, strength characteristically improves with repeated muscle use (as residual calcium accumulates presynaptically), a key clinical distinguishing feature.