**Core Concept**
Lambert-Eaton Myasthenic Syndrome (LEMS) is a rare autoimmune disorder characterized by muscle weakness, fatigue, and autonomic dysfunction. It is caused by antibodies against voltage-gated calcium channels (VGCCs) at the neuromuscular junction.

**Why the Correct Answer is Right**
The tensilon test, which involves administering edrophonium (a cholinesterase inhibitor), is typically positive in myasthenia gravis but negative in LEMS. This is because LEMS patients have impaired release of acetylcholine from the motor nerve terminals, making cholinesterase inhibitors less effective. In contrast, LEMS patients often have preserved or even increased nerve terminal release of acetylcholine in response to electrical stimulation, making decremental response to repeated electrical stimulation a characteristic feature. LEMS is indeed associated with adenocarcinoma of the lung, particularly small cell lung cancer. The ocular muscles are typically spared in LEMS, unlike in myasthenia gravis.

**Why Each Wrong Option is Incorrect**
**Option A:** The tensilon test is typically negative in LEMS, not positive.
**Option B:** Ocular muscles are indeed spared in LEMS, making this statement true.
**Option C:** Decremental response to repeated electrical stimulation is a characteristic feature of LEMS, making this statement true.
**Option D:** LEMS is indeed associated with adenocarcinoma of the lung, making this statement true.

**Clinical Pearl / High-Yield Fact**
LEMS can be challenging to diagnose, but a positive response to 3,4-diaminopyridine (a potassium channel blocker) can be a helpful diagnostic clue.

**Correct Answer: A. The tensilon test is typically negative in LEMSand not positive.