**Core Concept**
Perampanel is a medication used in the management of epilepsy, specifically for the treatment of focal seizures and generalized seizures. It works by selectively and competitively blocking the activity of AMPA receptors, a subtype of glutamate receptors, which are involved in the excitatory neurotransmission in the brain.

**Why the Correct Answer is Right**
Perampanel binds to the AMPA receptor GluR2 subunit, preventing the receptor from opening and allowing calcium ions to flow into the neuron. This reduces the excitatory neurotransmission and subsequent neuronal hyperexcitability, thereby controlling seizures. The AMPA receptor blockade also leads to a decrease in the release of excitatory neurotransmitters from the presynaptic neuron, further contributing to the anticonvulsant effect.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because perampanel does not work by blocking NMDA receptors, which are another subtype of glutamate receptors involved in excitatory neurotransmission. NMDA receptor antagonists, such as ketamine and memantine, have different mechanisms of action.
**Option B:** This option is incorrect because perampanel is not a GABA receptor agonist, which would enhance inhibitory neurotransmission. Instead, perampanel works by blocking excitatory neurotransmission through AMPA receptors.
**Option C:** This option is incorrect because perampanel does not have a significant effect on sodium channels, which are involved in the generation of action potentials. Other antiepileptic drugs, such as phenytoin and carbamazepine, work by blocking sodium channels.

**Clinical Pearl / High-Yield Fact**
Perampanel is unique among antiepileptic drugs in its mechanism of action as an AMPA receptor antagonist. This property makes it a valuable addition to the treatment arsenal for patients with focal and generalized seizures who are not adequately controlled by other medications.

**Correct Answer: B. Perampanel is a selective and competitive AMPA receptor antagonist.**