**Core Concept**
Neurocysticercosis is a parasitic infection caused by the larvae of the pork tapeworm (Taenia solium) that affects the central nervous system. It is a leading cause of epilepsy in developing countries and can present with a variety of neurological symptoms.

**Why the Correct Answer is Right**
Seizures are the most common presentation of neurocysticercosis due to the larval cysts' predilection for the cerebral cortex and basal ganglia. When the cysts degenerate, they release antigens that trigger an immune response, leading to inflammation and neuronal damage, which can cause seizures. This is often the first symptom of the disease and can occur even before any other symptoms appear.

**Why Each Wrong Option is Incorrect**
**Option B:** Focal neurological deficits, such as weakness or numbness, can occur in neurocysticercosis, but they are not as common as seizures.
**Option C:** Dementia is not a typical presentation of neurocysticercosis, although it can occur in rare cases where the infection affects the cerebral cortex.
**Option D:** Radiculopathy, which affects the nerve roots, is not a common presentation of neurocysticercosis, as the infection primarily affects the central nervous system.

**Clinical Pearl / High-Yield Fact**
Neurocysticercosis is often referred to as the "most common parasitic infection of the brain" and is a leading cause of epilepsy in developing countries. It is essential to consider this diagnosis in patients with unexplained seizures or focal neurological deficits, especially in regions where the infection is endemic.

**✓ Correct Answer: A. Seizures**